Flora of the Southeastern United States
2022 Edition

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Key to Plantaginaceae

1 Leaves alternate, at least those on the upper stem; calyx 5-merous; stamens 4.
..2 Corolla lacking a spur or pouch at the base; [tribe Digitaleae]
..2 Corolla with a distinct spur or broad pouch protruding between the 2 lower calyx lobes; [tribe Antirrhineae].
....3 Corolla with a broad pouch at the base (saccate or gibbose).
......4 Calyx lobes about equal, all shorter than the corolla tube; corolla 25-40 mm long; leaves to 15 mm wide
......4 Calyx lobes distinctly unequal, all longer than the corolla tube; corolla 10-13 mm long; leaves to 5 mm wide
....3 Corolla with a slender spur at the base.
........5 Flowers in terminal racemes
........5 Flowers solitary in leaf axils.
..........6 Stems erect; leaves linear
..........6 Stems prostrate; leaves orbicular, ovate, or triangular.
............ 7 Leaves orbicular in outline, palmately lobed and veined; stems rooting at nodes
............ 7 Leaves ovate or triangular, pinnately veined; stems not rooting
1 Leaves either strictly basal, or opposite or whorled throughout; calyx 0-, 4-, or 5-merous; stamens 1, 2, or 4.
............ ..8 Leaves strongly basally disposed, usually all the leaves basal; petals 4, scarious and translucent in texture; inflorescence a spike; [tribe Plantagineae]
............ ..8 Leaves cauline, either opposite or whorled; petal 0, or 4, or 5; inflorescence various.
............ ....9 Leaves whorled.
............ ......10 Aquatic; leaves 5-30 mm long, lanceolate, toothed to deeply dissected into linear segments; [tribe Gratioleae]
............ ......10 Terrestrial; leaves 40-15 cm long, lanceolate or elliptic, toothed; [tribe Veroniceae]
............ ....9 Leaves opposite.
............ ........11 Petals 0; sepals 0, stamens 1; leaves both < 2 cm long and entire; [tribe Callitricheae]
............ ........11 Petals 4 or 5; sepals 4 or 5; stamens 2 or 4; leaves > 2 cm long, or serrate, or both.
............ ..........12 Calyx and corolla 4-merous.
............ ............ 13 Leaves punctate; stamens 4; [tribe Gratioleae]
............ ............ 13 Leaves not punctate; stamens 2; [tribe Veroniceae]
............ ..........12 Calyx and corolla 5-merous.
............ ............ ..14 Plants erect, moderately robust, usually > 4 dm tall, larger leaves > 5 cm long; inflorescences terminal (the bracts subtending flowers strongly reduced in size in comparison to main leaves of the stem); [tribe Cheloneae].
............ ............ ....15 Inflorescence compact, the inflorescence axis generally hidden by the closely packed and overlapping flowers; each flower subtended by large overlapping bracts
............ ............ ....15 Inflorescence more diffuse, the inflorescence axis readily visible between the flowers; flowers lacking extra subtending bracts
............ ............ ..14 Plants creeping, decumbent or erect, small, usually < 4 dm tall (except Mecardonia, to 5 dm tall), larger leaves < 5 cm long; inflorescences axillary (all or most of the flowers axillary to more-or-less normally sized leaves).
............ ............ ......16 Stamens 2; [section Gratioleae].
............ ............ ........17 Capsule flattened, compressed in ×-section; capsule wider than long, notched; leaves dimorphic, with narrow submersed leaves on the lower stems, and broad floating leaves just subtending the aerial inflorescences; [of vernal pools on granite outcrops in Piedmont SC, GA, and AL]
............ ............ ........17 Capsule turgid, roundish in ×-section; capsule longer than wide; leaves monomorphic; [collectively of many habitats and widespread].
............ ............ ..........18 Flowers and fruits on definite pedicels; annual or perennial; leaves not papillose
............ ............ ..........18 Flowers and fruits sessile or subsessile, the pedicels < 1 mm long; perennial; leaves papillose on the surfaces and margins
............ ............ ......16 Stamens 4.
............ ............ ............ 19 Sepals evidently connate into a tube about as long as the lobes; [section Cheloneae]
............ ............ ............ 19 Sepals distinct or very nearly so.
............ ............ ............ ..20 Leaves deeply pinnatifid; [tribe Stemodieae]
............ ............ ............ ..20 Leaves entire or toothed; [tribe Gratioleae].
............ ............ ............ ....21 Corolla nearly radially symmetrical; corolla lobes about as long as the corolla tube; leaves palmately veined, with parallel veins diverging from the base, margins entire to crenulate; of aquatic to moist habitats, often somewhat succulent
............ ............ ............ ....21 Corolla distinctly bilabiate; corolla lobes shorter than the corolla tube; leaves pinnately veined, with a single main-vein and lateral veins diverging along it, margins serrate; of moist habitats, not succulent

Key N2: herbaceous dicots with mainly basal, simple leaves

1 Inflorescence an involucrate head subtended by phyllaries, the heads solitary or many and variously arrayed in secondary inflorescences, the ovary inferior, the corolla connate and tubular at least basally, the calyx absent, the stamens 5, the fruit a cypsela
1 Inflorescence, flower, and fruit structure various, but not with the combination of features as above (sometimes the flowers in a head subtended by bracts, e.g. Eryngium in APIACEAE, but then with other features differing, such as stamens 4, or green calyx present, or petals separate, or fruit a schizocarp of mericarps, etc.).
..2 Basal leaves 2-lobed, pinnately lobed, or palmately lobed (not considering cordate, hastate, or auriculate leaf bases as “lobed”).
....3 Basal leaves 2-lobed, hinged between the lobes, each lobe with stiff, marginal, eyelash-like bristles; [Coastal Plain of NC and SC, rarely planted and weakly naturalized elsewhere]
....3 Basal leaves 3-many-lobed, palmately or pinnately; [collectively widespread].
......4 Leaf lobing pinnate.
........5 Gynoecium of separate pistils (each with a single carpel); fruit an aggregate
........5 Gynoecium of a single pistil (with 2, rarely more, carpels); fruit simple.
..........6 Stamens many; sepals 2, petals 4; fresh plants with yellow, orange, or white milky juice
..........6 Stamens 4, 5, or 6; sepals 4 or 5; petals 4 or 5.
............ 7 Petals 4, distinct; stamens 6
............ 7 Petals 5, fused; stamens 2, 4, or 5.
............ ..8 Corolla radially symmetrical; stamens 5
............ ..8 Corolla 2-lipped, bilaterally symmetrical or asymmetrical; stamens 2 or 4.
............ ....9 Corolla lobes not twisted, the flower bilaterally symmestrical; stamens 2
............ ....9 Corolla lobes twisted so as to make the flower asymmetrical; stamens 4
......4 Leaf lobing palmate.
............ ......10 Petiole attachment peltate.
............ ........11 Leaves < 10 cm in diameter
............ ........11 Leaves > 15 cm in diameter
............ ......10 Petiole attachment marginal.
............ ..........12 Ovary inferior.
............ ............ 13 Petals 4; stamens 8; fruit a capsule
............ ............ 13 Petals 5; stamens 5; fruit a schizocarp of 2 mericarps.
............ ............ ..14 Fruit tuberculate; leaves 3-lobed
............ ............ ..14 Fruit smooth; leaves with 5 or more lobes
............ ..........12 Ovary superior, or half-inferior by fusion of a hypanthium a part of the way up the ovary wall.
............ ............ ....15 Gynoecium of separate pistils (each with a single carpel); fruit an aggregate.
............ ............ ......16 Perianth of 5 green sepals and 5 colored petals.
............ ............ ........17 Carpels partly fused, arrayed in a ring of 10-20
............ ............ ........17 Carpels separate, spiral, many
............ ............ ......16 Perianth of a single whorl of 3-12 petaloid sepals (the petals absent or small and rudimentary).
............ ............ ..........18 Leaves 2, the single flower terminal and associated with the upper leaf; fruit an aggregate of berries
............ ............ ..........18 Leaves normally > 2, flowers not as above; fruit an aggregate of achenes, utricles, or follicles
............ ............ ....15 Gynoecium of a single pistil (with 1-5 carpels); fruit simple.
............ ............ ............ 19 Hypanthium present, partially fused or not fused to the pistil; ovary partially inferior to superior
............ ............ ............ 19 Hypanthium absent; ovary superior.
............ ............ ............ ..20 Petals connate at base; leaves sharply toothed
............ ............ ............ ..20 Petals distinct; leaves with rounded lobes or teeth.
............ ............ ............ ....21 Corolla radially symmetrical; petals 8-12; capsule fusiform, narrowed to both ends, > 5× as long as wide
............ ............ ............ ....21 Corolla bilaterally symmetrical; petals 5; capsule ovoid, < 2× as long as wide
..2 Basal leaves not lobed, at most serrate or crenate (and sometimes also cordate, hastate, auriculate, or peltate at the base).
............ ............ ............ ......22 Basal leaves petiolate, the blade with a cordate, hastate, auriculate, or peltate base.
............ ............ ............ ........23 Leaf margins entire.
............ ............ ............ ..........24 Inflorescence a terminal and/or axillary raceme, panicle, or cyme of many small flowers; fruit an achene; perianth uniseriate, of 0, 4-5, or 6 tepals.
............ ............ ............ ............ 25 Flowers unisexual; staminate flowers 4-5 tepals, pistillate flowers lacking a perianth
............ ............ ............ ............ 25 Flowers bisexual; flowers with 6 tepals
............ ............ ............ ..........24 Inflorescence either a terminal spike, or a 1-7-flowered terminal cyme, or of a solitary axillary or terminal flower; fruit various; perianth biseriate (of differentiated sepals and petals (except uniseriate, of 3 fused sepals in ARISTOLOCHIACEAE).
............ ............ ............ ............ ..26 Flowers bilaterally symmetrical; inflorescence a terminal spike (with > 20 flowers); petals 4, usually scarious, transparent; sepals 4, green; stamens 4
............ ............ ............ ............ ..26 Flowers radially symmetrical; inflorescence either of a solitary flower or of a 1-7-flowered terminal cyme; petals 5, 8-12, or 0; sepals 5 (green), 3 (brown), or 5-9 (yellow); stamens 5, 12, or many.
............ ............ ............ ............ ....27 Gynoecium of separate pistils (each with a single carpel); fruit an aggregate of achenes or follicles; flowers bright yellow, either of 5-9 distinct petaloid sepals, or of 8-12 distinct petals subtended by 3-4 green distinct sepals
............ ............ ............ ............ ....27 Gynoecium either of a single pistil with 6 carpels or of a single pistil with 4 carpels or of 2 nearly separate carpels; fruit a simple capsule (or deeply 2-lobed); flowers white, brown, or greenish, either of 5 fused or distinct white petals and 5 fused or distinct green sepals, or of 3 fused brown or greenish petaloid sepals.
............ ............ ............ ............ ......28 Flowers brown or green, of 3 fused brown or greenish petaloid sepals (and 0 petals); carpels 6; stamens 12; leaves 4-10 cm wide
............ ............ ............ ............ ......28 Flowers white, of 5 white or whitish petals and 5 green sepals; carpels 2; stamens 5; leaves 1-12 (-15) cm wide
............ ............ ............ ............ ........29 Petals separate; sepals separate; plant glabrous
............ ............ ............ ............ ........29 Petals fused; sepals fused; carpels 2; plant pubescent.
............ ............ ............ ............ ..........30 {XXXX}; [common, widespread in our area]
............ ............ ............ ............ ..........30 {YYYY}; [rare alien]
............ ............ ............ ........23 Leaf margins crenate, serrate, or incised.
............ ............ ............ ............ ............ 31 Gynoecium of separate pistils (each with a single carpel); fruit an aggregate; perianth of 5 green sepals and 5 colored petals.
............ ............ ............ ............ ............ ..32 Carpels 10-20, partly fused, arrayed in a ring; petals white, pink, red, or purplish
............ ............ ............ ............ ............ ..32 Carpels many, separate, spiral; petals yellow or white.
............ ............ ............ ............ ............ ....33 Flowers lacking a hypanthium; fruit an aggregate of achenes or aggregate of follicles
............ ............ ............ ............ ............ ....33 Flowers with a hypanthium; fruit an aggregate of drupelets or aggregate of achenes
............ ............ ............ ............ ............ 31 Gynoecium of a single pistil (with 1-5 carpels); fruit simple.
............ ............ ............ ............ ............ ......34 Flowers bilaterally symmetrical; inflorescence of a solitary flower; fruit a 3-locular capsule
............ ............ ............ ............ ............ ......34 Flowers radially symmetrical; inflorescence an umbel (or composite of umbelliform units, or a terminal panicle.
............ ............ ............ ............ ............ ........35 Ovary superior; inflorescence a terminal panicle or terminal raceme.
............ ............ ............ ............ ............ ..........36 Inflorescence a terminal raceme; perianth of 4 green sepals and 4 white petals; fruit a silique/silicle; fresh foliage in spring and summer with a strong garlic odor; larger leaves < 10 cm in diameter
............ ............ ............ ............ ............ ..........36 Inflorescence a terminal panicle; perianth of 6 cream-colored petaloid sepals; fruit a winged achene; fresh foliage lacking a garlic odor; larger leaves typically > 30 cm in diameter
............ ............ ............ ............ ............ ........35 Ovary inferior; inflorescence an umbel (or a composite of umbellate units); fruit a schizocarp of mericarps.
............ ............ ............ ............ ............ ............ 37 Petiole attachment peltate
............ ............ ............ ............ ............ ............ 37 Petiole attachment marginal (the blade cleft to the petiole.
............ ............ ............ ............ ............ ............ ..38 Leaf blades longer than wide, sharply V-cleft at the base and otherwise shallowly denticulate
............ ............ ............ ............ ............ ............ ..38 Leaf blades as broad or broader than long, cleft at the base and also irregularly serrate or crenate around the margin
............ ............ ............ ......22 Basal leaves petiolate or not, with a truncate, rounded, or cuneate leaf base.
............ ............ ............ ............ ............ ............ ....39 Leaves tubular, with a sutured ventral flange, erect or reclining, adapted as a pitfall for insects (flat, phyllodial leaves sometimes present as well, common in the winter in some species, such as S. oreophila)
............ ............ ............ ............ ............ ............ ....39 Leaves flat, not sutured into a tubular shape.
............ ............ ............ ............ ............ ............ ......40 Stem leaves opposite; perianth 5-merous, at least the corolla bilaterally symmetrical (barely so in VALERIANACEAE), or the parts curved so as to be asymmetrical (Pedicularis in OROBANCHACEAE); stamens 2, 3, or 4.
............ ............ ............ ............ ............ ............ ........41 Ovary inferior; stamens 3
............ ............ ............ ............ ............ ............ ........41 Ovary superior; stamens 2 or 4.
............ ............ ............ ............ ............ ............ ..........42 Corolla narrowly tubular, the five lobes flaring at nearly 90 degrees and nearly radially symmetrical
............ ............ ............ ............ ............ ............ ..........42 Corolla distinctly 2-lipped (with prominently large upper and lower corolla lobes) or hooded (the upper lip hood-like), distinctly bilaterally symmetrical, or the lobes twisted so as to make the corolla asymmetrical.
............ ............ ............ ............ ............ ............ ............ 43 Corolla yellow, the upper lip often slightly to strongly maroon, hooded but the corolla lobes twisted so as to make the flower asymmetrical
............ ............ ............ ............ ............ ............ ............ 43 Corolla white, lavender, or blue, 2-lipped and bilaterally symmetrical.
............ ............ ............ ............ ............ ............ ............ ..44 Sepals separate to the base or nearly so, not forming a tube
............ ............ ............ ............ ............ ............ ............ ..44 Sepals connate for at least 0.3× their length to form a tube
............ ............ ............ ............ ............ ............ ......40 Stem leaves alternate; perianth radially symmetrical (less commonly bilaterally symmetrical); stamens 5, 6-8, 9, 10 (rarely 4).
............ ............ ............ ............ ............ ............ ............ ....45 Ovary inferior (or half-inferior in Samolus).
............ ............ ............ ............ ............ ............ ............ ......46 Perianth 4-merous; stamens 8
............ ............ ............ ............ ............ ............ ............ ......46 Perianth 5-merous; stamens 5.
............ ............ ............ ............ ............ ............ ............ ........47 Inflorescence an umbel; fruit a schizocarp of 2 mericarps
............ ............ ............ ............ ............ ............ ............ ........47 Inflorescence an axillary or terminal raceme; fruit a capsule
............ ............ ............ ............ ............ ............ ............ ....45 Ovary superior.
............ ............ ............ ............ ............ ............ ............ ..........48 Pistils many, each with a single carpel; fruit an aggregate of achenes
............ ............ ............ ............ ............ ............ ............ ..........48 Pistil 1, with 1-5 carpels; fruit simple (a legume, silique/silicle, capsule, utricle, or schizocarp of 4 nutlets).
............ ............ ............ ............ ............ ............ ............ ............ 49 Corolla bilaterally symmetrical (barely so in Limosella in SCROPHULARIACEAE); stamens 2, 4, 6, 8, or 10.
............ ............ ............ ............ ............ ............ ............ ............ ..50 Stamens 6-8 or 10.
............ ............ ............ ............ ............ ............ ............ ............ ....51 Petals separate; stamens 10
............ ............ ............ ............ ............ ............ ............ ............ ....51 Petals fused; stamens 10 or 6-8.
............ ............ ............ ............ ............ ............ ............ ............ ......52 Stamens 10, monadelphous
............ ............ ............ ............ ............ ............ ............ ............ ......52 Stamens 6-8, epipetalous
............ ............ ............ ............ ............ ............ ............ ............ ..50 Stamens 2 or 4.
............ ............ ............ ............ ............ ............ ............ ............ ........53 Stamens 2
............ ............ ............ ............ ............ ............ ............ ............ ........53 Stamens 4.
............ ............ ............ ............ ............ ............ ............ ............ ..........54 [plants of coastal wetlands]
............ ............ ............ ............ ............ ............ ............ ............ ..........54 [plants of uplands or inland seeps or fens]
............ ............ ............ ............ ............ ............ ............ ............ ............ 55 Flowers (and subtending bracts) red or yellow
............ ............ ............ ............ ............ ............ ............ ............ ............ 55 Flowers purple, blue, or lavender
............ ............ ............ ............ ............ ............ ............ ............ 49 Corolla radially symmetrical; stamens 5, 10, 4-6, or 9.
............ ............ ............ ............ ............ ............ ............ ............ ............ ..56 Perianth of 6 tepals; stamens 4-6 or 9; carpels 3
............ ............ ............ ............ ............ ............ ............ ............ ............ ..56 Perianth of green sepals and more brightly colored petals; stamens 5 or 10; carpels 2, 3, 4, or 5.
............ ............ ............ ............ ............ ............ ............ ............ ............ ....57 Leaves covered with sticky, gland-tipped hairs (often red), as flypaper traps for insects
............ ............ ............ ............ ............ ............ ............ ............ ............ ....57 Leaves lacking sticky gland-tipped hairs.
............ ............ ............ ............ ............ ............ ............ ............ ............ ......58 Fruit a schizocarp of 4 nutlets (ovary obviously 4-lobed in flower)
............ ............ ............ ............ ............ ............ ............ ............ ............ ......58 Fruit a capsule or silique/silicle (or utricle in Limonium in PLUMBAGINACEAE).
............ ............ ............ ............ ............ ............ ............ ............ ............ ........59 Inflorescence of a solitary, terminal flower; carpels 2-3 (-4).
............ ............ ............ ............ ............ ............ ............ ............ ............ ..........60 Corolla with a long tube and flaring corolla lobes (united > ½ its length)
............ ............ ............ ............ ............ ............ ............ ............ ............ ..........60 Corolla of separate petals or united only for a short length (< ¼ its length).
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ 61 Leaves serrate
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ 61 Leaves entire
............ ............ ............ ............ ............ ............ ............ ............ ............ ........59 Inflorescence of several to many flowers; carpels 5 (3 in Galax in DIAPENSIACEAE).
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ..62 Inflorescence an umbel; petals recurved, pink to almost white
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ..62 Inflorescence a raceme or panicle.
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ....63 Fruit a silique/silicle; petals 4; stamens 6
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ....63 Fruit either a capsule or a utricle; petals 5; stamens 5 or 10.
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ......64 Inflorescence a somewhat to very diffuse panicle, with 3 or more orders of branching, not giving at all the impression that the overall inflorescence is made of racemose units.
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ........65 Leaves entire; stamens 5; [plants of tidal marshes]
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ........65 Leaves serrate or crenate; stamens 10; [plants of various habitats, especially rock outcrops and bottomland forests and streambanks, never in tidal marshes]
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ......64 Inflorescence either a single terminal raceme (sometimes spike-like), or of 1 to several terminal and axillary racemes (these sometimes combined into a diffuse panicle, but one whose structure is clearly made up of many racemes).
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ..........66 Inflorescence of 1-several terminal and axillary racemes, the plant typically well-branched, especially from the base; stamens 5
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ..........66 Inflorescence of a single, terminal raceme, the plant unbranched; stamens 10 (or 5, with 5 staminodes)
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ............ 67 Inflorescence spike-like, the flowers many (> 40), barely pedicelled; capsule 3-locular
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ............ 67 Inflorescence a raceme, the flowers fewer (< 20) and distinctly pedicelled; capsule 5-locular

Key S1: herbaceous dicots with opposite, simple, and unlobed leaves on the stem

1 Inflorescence an involucrate head subtended by phyllaries, the heads solitary or many and variously arrayed in secondary inflorescences, the ovary inferior, the corolla connate and tubular at least basally, the calyx absent, the stamens 5, the fruit a cypsela
1 Inflorescence, flower, and fruit structure various, but not with the combination of features as above (sometimes the flowers in a head, e.g. Pycnanthemum in LAMIACEAE, but then with other features differing, such as stamens 4, or green calyx present, or fruit a schizocarp of mericarps, etc.).
..2 Leaves scale-like, stems fleshy; flowers embedded in the fleshy stem, no perianth present; [saline environments (coastal or rarely inland)].
..2 Leaves small to large; stems not fleshy; flowers sessile or on pedicels; [collectively of many habitats, saline and not].
....3 Ovary inferior or partially inferior.
......4 Perianth of a single whorl (petals absent) (note that in Mirabilis in NYCTAGINACEAE the petaloid calyx is subtended by a 5-lobed fused set of involucral bracts).
........5 Leaves herbaceous, suborbicular, about as long as wide or wider than long; calyx 3- or 4-merous; stamens 4, 8, or 12.
..........6 Plant ascending, with a single node (2 leaves); leaves > 6 cm long and wide; calyx 3-merous, brown to yellowish; stamens 12
..........6 Plant creeping, with many nodes; leaves 3-15 mm long and wide; calyx 4-merous, yellow to greenish; stamens 4 or 8
........5 Leaves fleshy, linear, lanceolate, to broadly ovate, at least slightly longer than broad; calyx 5-merous; stamens 3, 5, or 10.
............ 7 Flowers axillary, sessile or nearly so, solitary or a few; petaloid sepals widely spreading, separate; leaves linear to oblanceolate; stamens 5 or 30-50
............ 7 Flowers in terminal cymose panicles; petaloid sepals connate into a narrow tube (reminiscent of the corolla of Ipomoea); leaves lanceolate, elliptic, ovate, or broadly ovate; stamens 3 or 5
......4 Perianth in 2 whorls (sepals and petals both present).
............ ..8 Petals distinct; inflorescence diffuse.
............ ....9 Leaves distinctly 3-veined from the base, the 3 veins converging again at the leaf apex
............ ....9 Leaves with prominently pinnate venation
............ ..8 Petals connate into a tube (at least basally); inflorescence often a head or dense terminal cyme (also axillary, or solitary on long peduncles).
............ ......10 Petals 5; stamens 3, 4, or 5
............ ........11 Creeping subshrub; flowers paired at tip of an upright peduncle
............ ........11 Upright herb; flowers in axils or terminal corymbs
............ ..........12 Flowers in terminal corymbs; fruit dry
............ ..........12 Flowers axillary; fruit fleshy
............ ......10 Petals 4 (or 6 or 8 in Richardia in RUBIACEAE); stamens 4, 6, or 8.
............ ............ 13 Inflorescence a head, subtended by 4 large bright white bracts
............ ............ 13 Inflorescence a head or more diffuse (see below), sometimes subtended by green bracts.
............ ............ ..14 Leaves serrate; corolla bilaterally symmetrical (especially the flowers near the outer edge of the head); inflorescence a head
............ ............ ..14 Leaves entire; corolla radially symmetrical; inflorescence a head or more diffuse (see below).
............ ............ ....15 Petals acute; flowers in terminal panicles, cymes, or panicles, or axillary; plant habit various, not simultaneously with all the characters below
............ ............ ....15 Petals broadly rounded; flowers axillary, solitary; plant a diffusely branched herb with linear leaves
....3 Ovary superior.
............ ............ ......16 Perianth of a single whorl (petals absent) or missing entirely (petals and sepals both absent). {key lead number needs adjusting}
............ ............ ........17 Inflorescence a cyathium, consisting of a single pistillate flower (reduced to a single 3-carpellate pistil) and 2 or more staminate flowers (each reduced to 1 stamen), borne in a cup-like involucre, the involucre bearing pointed or rounded glands, these sometimes brightly colored and petaloid, mimicking an individual flower (the cyathia then secondarily arranged in terminal cymes, or solitary and axillary, etc.); fresh plants with milky juice; fruit a 3-lobed, 3-locular capsule
............ ............ ........17 Inflorescence not a cyathium (and staminate or bisexual flowers with > 1 stamen, except Callitriche in PLANTAGINACEAE); fresh plants lacking milky juice; fruit various, not as above.
............ ............ ..........18 Flowers 1 (or 2) in leaf axils; leaves entire.
............ ............ ............ 19 Flowers unisexual; sepals 0; flowers (staminate) with 1 stamen
............ ............ ............ 19 Flowers bisexual; sepals 4; flowers with 2, 4, or 6 stamens.
............ ............ ............ ..20 {XXXX}
............ ............ ............ ..20 {YYYY}
............ ............ ..........18 Flowers many, in axillary spikes, cymes, or glomerules, or in terminal spikes, heads, cymes, or panicles; leaves entire or serrate.
............ ............ ............ ....21 Fruit a 2-locular capsule; {XXXX}
............ ............ ............ ....21 Fruit single-seeded, an achene or utricle; {YYYY}.
............ ............ ............ ......22 Leaves serrate, regularly and sharply so; plants with stinging hairs (or not)
............ ............ ............ ......22 Leaves entire, or with a few very obscure crenations (Iresine) or basally disposed rounded lobe-like teeth (Atriplex); plants without stinging hairs.
............ ............ ............ ........23 Leaves of a pair slightly to strongly different in size
............ ............ ............ ........23 Leaves of a pair the same size.
............ ............ ............ ..........24 Styles 1-2 (-3); leaves 2-30 mm long, 0.5-8 mm wide, linear or narrowly elliptic
............ ............ ............ ..........24 Style 1; leaves generally either longer than 30 mm, or wider than 8 mm (if linear and smaller than those dimensions, then fleshy).
............ ............ ............ ............ 25 Tepals scarious; inflorescence of heads, spikes, or panicles
............ ............ ............ ............ 25 Tepals herbaceous; inflorescence of glomerules, these axillary or arrayed in spikes or panicles
............ ............ ......16 Perianth in 2 whorls (sepals and petals both present).
............ ............ ............ ............ ..26 Gynoecium of 4-many pistils, each 1-carpellate.
............ ............ ............ ............ ....27 Pistils 4-5, in a single whorl; stamens 4, 5, 8, or 10; fruit an aggregate of follicles
............ ............ ............ ............ ....27 Pistils many, spiral; stamens many; fruit an aggregate of plumose achenes
............ ............ ............ ............ ..26 Gynoecium either of 1 pistil (with 1 or more carpels), or of 2 pistils, united only by the style and stigma (APOCYNACEAE).
............ ............ ............ ............ ......28 Petals not at all connate, not even at their bases.
............ ............ ............ ............ ........29 Leaves with pellucid punctate glands (most easily visible with transmitted light); stamens often fascicled into 3, 4, or 5 fascicles; petals yellow or pinkish
............ ............ ............ ............ ........29 Leaves lacking pellucid punctate glands; stamens not fascicled; petals variously colored.
............ ............ ............ ............ ..........30 Sepals 2; stamens opposite the petals
............ ............ ............ ............ ..........30 Sepals 3-7; stamens opposite the sepals.
............ ............ ............ ............ ............ 31 Petals 3; sepals 5, dimorphic, the 2 outer sepals narrower than the 3 inner and concave sepals; stamens (3-) 5-15 (-25)
............ ............ ............ ............ ............ 31 Petals 4-7; sepals 4-7, normally monomorphic; stamens 4, 5, 6, 8, 10, or 12 (or sometimes rarely 2 or 3).
............ ............ ............ ............ ............ ..32 Capsule 2-5 (-6) locular; style 1; perianth 4-7-merous; stamens 4, 6, 8, 10, or 12
............ ............ ............ ............ ............ ..32 Capsule either 1-locular of 10-locular; styles 2-5; perianth 4-5-merous; stamens 4, 5, 8, or 10 (or rarely 2 or 3).
............ ............ ............ ............ ............ ....33 Capsule 1-locular, dehiscent apically by teeth or valves; sepals connate into a tube or separate; styles 2-5; perianth 4-5-merous; stamens 4, 5, 8, or 10 (or rarely 2 or 3)
............ ............ ............ ............ ............ ....33 Capsule 10-locular (each of the 5 carpels divided at maturity), septicidal; sepals distinct or nearly so; styles 5, perianth 5-merous; stamens 5
............ ............ ............ ............ ......28 Petals connate at least for a short distance at their bases.
............ ............ ............ ............ ............ ......34 Corolla radially symmetrical (or so slightly bilaterally symmetrical as to be mistakable as radially symmetrical); stamens as many as the corolla lobes (or 1 less in Ruellia in ACANTHACEAE, Buchnera in OROBANCHACEAE, Trichostema in LAMIACEAE, and Verbena in VERBENACEAE); carpels 2 or 3.
............ ............ ............ ............ ............ ........35 Pistils 2, united only by the style and stigma; fruit a schizocarp of 2 1-carpellate follicles (often single by abortion); plant with milky juice when fresh (except Catharanthus); leaves entire
............ ............ ............ ............ ............ ........35 Pistil 1 (of 2-5 fused carpels); fruit either a 2-5-carpellate capsule or of 2 or 4 1-seeded nutlets derived from 2 carpels; plant lacking milky juice; leaves entire or serrate.
............ ............ ............ ............ ............ ..........36 Ovary and capsule 3-5-carpellate; capsule 3- or 1-locular.
............ ............ ............ ............ ............ ............ 37 Sepals 2
............ ............ ............ ............ ............ ............ 37 Sepals 5.
............ ............ ............ ............ ............ ............ ..38 Inflorescence a terminal cyme; corolla salverform, with an elongated and very narrow tube, pink or white; capsule 3-locular
............ ............ ............ ............ ............ ............ ..38 Inflorescence various but not cymose, of terminal or axillary racemes or panicles, or of solitary axillary flowers; corolla connate only at the base, the petals appearing nearly separate (not salverform); capsule 1-locular
............ ............ ............ ............ ............ ..........36 Ovary and capsule 2-carpellate; fruit either a 2-locular capsule or of 2 or 4 1-seeded nutlets derived from 2 carpels.
............ ............ ............ ............ ............ ............ ....39 Stamens 4-12, the same number as the corolla lobes; corolla (and the flower as a whole) strictly radially symmetrical.
............ ............ ............ ............ ............ ............ ......40 Capsule septicidal; corolla white, pink, blue, yellowish white, or greenish white; inflorescence either a terminal or axillary cyme, or a terminal panicle or raceme, or a terminal or axillary cyme reduced to 1 or a few flowers
............ ............ ............ ............ ............ ............ ......40 Capsule loculicidal and also deeply 2-lobed; corolla white, pink, or scarlet with a yellow interior; inflorescence of cymosely arranged spikes
............ ............ ............ ............ ............ ............ ....39 Stamens either 4, 1 fewer than the 5 corolla lobes, or 2 (with 2 staminodes); corolla usually slightly bilaterally symmetrical (the flower as a whole made bilaterally symmetrical by the 2 or 4 stamens).
............ ............ ............ ............ ............ ............ ........41 Leaves entire; corolla tube flaring for all of its length
............ ............ ............ ............ ............ ............ ..........42 Fruit a schizocarp of 4 1-seeded nutlets; inflorescence terminal, of cymes; corolla ca. 5 mm long; leaves prominently 3-veined
............ ............ ............ ............ ............ ............ ..........42 Fruit a capsule; inflorescence axillary, of cymes or clusters (often reduced to a solitary flower); corolla > 12 mm long; leaves with single primary vein
............ ............ ............ ............ ............ ............ ........41 Leaves serrate; corolla salverform, the tube narrow and nearly the same diameter for most of its length; inflorescence a terminal spike, raceme, raceme of racemes, or head.
............ ............ ............ ............ ............ ............ ............ 43 Fruit a 2-locular capsule; stamens inserted near the base of the corolla tube
............ ............ ............ ............ ............ ............ ............ 43 Fruit a schizocarp of 4 mericarps; stamens inserted near or above the middle of the corolla tube
............ ............ ............ ............ ............ ......34 Corolla bilaterally symmetrical (or the corolla 2-lipped but the corolla lobes twisted so as to make the flower asymmetrical); fertile stamens fewer than the corolla lobes (except Plantago in PLANTAGINACEAE, which is equal, with 4 each; a few genera have a 5th, sterile, stamen which is obviously different in form than the 4 fertile stamens) (note that many corollas are bilabiate and the number of corolla lobes, 4 or 5, may be difficult to interpret); carpels 2.
............ ............ ............ ............ ............ ............ ............ ..44 Carpels 2, each carpel slightly to deeply lobed, separating at maturity into 4 half-carpellate units (not separating in Phyla in VERBENACEAE); fruit a schizocarp of 4 mericarps (or 2 nutlets in Phyla in VERBENACEAE).
............ ............ ............ ............ ............ ............ ............ ....45 Inflorescence a thyrse, verticillaster, or terminal cyme, the flowers borne in cymose lateral branches; corolla strongly bilaterally symmetrical (rarely nearly radially symmetrical); stems square in ×-section (or sometimes rounded, especially on older growth); fresh plants often (but not always) aromatic
............ ............ ............ ............ ............ ............ ............ ....45 Inflorescence of spikes, racemes, or heads, the flowers or fruits single at nodes; corolla often nearly radially symmetrical; stems rounded in X-section (rarely square); fresh plants usually not aromatic
............ ............ ............ ............ ............ ............ ............ ..44 Carpels 2, unlobed; fruit a capsule (or an achene in Phryma).
............ ............ ............ ............ ............ ............ ............ ......46 Stamens 2.
............ ............ ............ ............ ............ ............ ............ ........47 Corolla 4 lobed, almost radially symmetrical; corolla scarious, white, or bluish
............ ............ ............ ............ ............ ............ ............ ........47 Corolla 4-5-lobed, either strongly bilabiate or salverform (Pseuderanthemum in ACANTHACEAE); white, blue, or yellow.
............ ............ ............ ............ ............ ............ ............ ..........48 Inflorescence an axillary cluster or spike
............ ............ ............ ............ ............ ............ ............ ..........48 Inflorescence of solitary (rarely 2) axillary flower. {add [Hypoestes] ACANTHACEAE}
............ ............ ............ ............ ............ ............ ............ ............ 49 Sepals 4
............ ............ ............ ............ ............ ............ ............ ............ 49 Sepals 5, distinct or nearly so.
............ ............ ............ ............ ............ ............ ............ ............ ..50 Corolla barely bilaterally symmetrical, the lobes about as long as the tube; outer sepals ovate, much wider than the inner sepals
............ ............ ............ ............ ............ ............ ............ ............ ..50 Corolla distinctly bilabiate, the lobes shorter than the tube; sepals of nearly the same width.
............ ............ ............ ............ ............ ............ ............ ............ ....51 Sterile stamens (the lower pair) consisting of slender filaments
............ ............ ............ ............ ............ ............ ............ ............ ....51 Sterile stamens minute or completely absent
............ ............ ............ ............ ............ ............ ............ ......46 Stamens 4.
............ ............ ............ ............ ............ ............ ............ ............ ......52 Corolla 5-lobed, distinctly bilabiate or in some nearly radially symmetrical; corolla colored.
............ ............ ............ ............ ............ ............ ............ ............ ........53 Flowers in terminal racemes, panicles, or spikes, the inflorescence not interspersed with large, leaf-like bracts.
............ ............ ............ ............ ............ ............ ............ ............ ..........54 Sepals separate to the base or nearly so, not forming a tube
............ ............ ............ ............ ............ ............ ............ ............ ..........54 Sepals connate for at least 0.3× their length to form a tube (this cup-like and flaring in Scrophularia in SCROPHULARIACEAE).
............ ............ ............ ............ ............ ............ ............ ............ ............ 55 Inflorescence a diffuse panicle; corolla 5-11 mm long, reddish-brown (sometimes with some yellow); fruit a septicidal capsule
............ ............ ............ ............ ............ ............ ............ ............ ............ 55 Inflorescence of 1 or more terminal (and sometimes upper axillary) spikes or racemes; corolla 10-50 mm long (6-8 mm long in Phryma in PHRYMACEAE), white, pink, blue, purple, or yellow; fruit either a loculicidal capsule (OROBANCHACEAE) or a single seeded achene (Phryma in PHRYMACEAE).
............ ............ ............ ............ ............ ............ ............ ............ ............ ..56 Corolla 10-50 mm long, pink, blue, purple, or yellow; fruit a loculicidal capsule
............ ............ ............ ............ ............ ............ ............ ............ ............ ..56 Corolla 6-8 mm long, white to pale pink; fruit a 1-seeded achene contained in the accrescent calyx, this “lopping down” against the inflorescence axis
............ ............ ............ ............ ............ ............ ............ ............ ........53 Flowers axillary and solitary, borne in the axils of normally-sized leaves or somewhat reduced but still large and leaf-like bracts [some taxa keyed here and below].
............ ............ ............ ............ ............ ............ ............ ............ ............ ....57 Sepals separate to the base or nearly so, not forming a tube.
............ ............ ............ ............ ............ ............ ............ ............ ............ ......58 Corolla distinctly bilabiate
............ ............ ............ ............ ............ ............ ............ ............ ............ ......58 Corolla not bilabiate, only slightly bilaterally symmetrical.
............ ............ ............ ............ ............ ............ ............ ............ ............ ........59 Leaves serrate, 2.0-4.5 cm long; plant usually blackening on drying
............ ............ ............ ............ ............ ............ ............ ............ ............ ........59 Leaves entire, either mostly larger or smaller [see below]; plant not blackening on drying
............ ............ ............ ............ ............ ............ ............ ............ ............ ..........60 Leaves 0.6-2.8 cm long, round, obovate, or broadly elliptic, < 1.8× as long as wide; plants creeping, ascending to 3 dm tall; [plants of wet places]
............ ............ ............ ............ ............ ............ ............ ............ ............ ..........60 Leaves 3-30 cm long, narrowly elliptic to lanceolate, > 2× as long as wide; plants erect or the stems sprawling; [plants mostly of uplands]
............ ............ ............ ............ ............ ............ ............ ............ ............ ....57 Sepals connate for at least 0.3× their length to form a tube.
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ 61 Corolla yellow, orange, or red.
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ..62 Calyx lobes longer than the tube, or as long as the tube, corolla 25-50 mm long; plants usually blackening on drying
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ..62 Calyx lobes shorter than the tube; corolla 14-22 mm long; plants not blackening on drying.
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ....63 Corolla red or orange, with a very narrow, cylindrical tube, the lobes then flaring into a limb about 1 cm across; plants blackening on drying; [rare alien, in crop fields, a noxious hemiparasitic weed under quarantine]
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ....63 Corolla yellow, not narrowly cylindrical, the lower lip arched; plants not blackening on drying; [rare, in seepage wetlands]
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ 61 Corolla white, pale blue, lavender, or pink (sometimes with some yellow).
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ......64 Corolla pink (sometimes almost white), often lined with yellow inside; leaves narrowly linear, often filiform (except lanceolate in A. auriculata); plants usually blackening on drying (some species do not); corolla not strongly bilabiate
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ......64 Corolla white, blue, or combinations of blue and white (sometimes with some yellow markings); leaves broader, mostly lanceolate; plants not blackening on drying; corolla strongly bilabiate.
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ........65 Upper lip of the corolla hooded, enfolding the anthers
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ........65 Upper lip of the corolla not hooded and enclosing the anthers; plants not blackening on drying.
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ..........66 Corolla blue; lower lip of the corolla arched upwards into the throat; plants perennial from rhizomes or crowns, 3-13 dm tall
............ ............ ............ ............ ............ ............ ............ ............ ............ ............ ..........66 Corolla bicolored, the upper lip white or very pale blue, the lower lip bright blue; lower lip of the corolla folded downward into a pouch enfolding the anthers; plants annuals, 0.5-4 dm tall