Flora of the Southeastern United States

1 Capsule turgid, longer than wide; leaves monomorphic; [collectively of many habitats and widespread].

  2 Flowers and fruits sessile or subsessile, the pedicels < 1 mm long; perennial.

    3 Leaves linear-subulate; corolla 2-3× as long as the calyx

    3 Leaves ovate; corolla 1-1.5 × as long as the calyx

  2 Flowers and fruits on definite pedicels; annual or perennial.

      4 Leaves clasping or subclasping-rounded at the base; perennial; [section Gratiola].

        5 Calyx subtended by 0 (-1) bractlet; corolla lobes white; corolla tube greenish yellow, conspicuously veined

        5 Calyx subtended by 2 bractlets; corolla lobes white or yellow-orange; corolla tube greenish yellow and conspicuously veined, or orange and not conspicuously veined.

          6 Corolla lobes and tube yellow-orange (very rarely white), not conspicuously veined; sepals and flower stalks sparsely or not at all glandular-puberulent

          6 Corolla lobes white to lavender, corolla tube greenish yellow, usually conspicuously veined; sepals and flower stalks densely glandular-puberulent.

             7 Leaves oblong-ovate to ovate (or linear-lanceolate in submersed forms), finely dentate; corolla veined with purple lines; sepals lanceolate to oblong-lanceolate

             7 Leaves triangular to lanceolate, margins entire, or with a few teeth toward the tip; corolla veined with brown lines; sepals linear-lanceolate

               8 Leaves 3.5× as long as wide; lower leaf surface with only sunken, translucent glands

               8 Leaves < 3× as long as wide; lower leaf surface with large, yellow sessile glands and sunken, translucent glands

      4 Leaves cuneate at the base; annual; [section Nibora].

                 9 Corolla yellow; [LA and TX]

                 9 Corolla white (or with pink or purple flush); [collectively widespread].

                   10 Pedicels stout, erect, 1-5 (-12) mm long

                   10 Pedicels slender, spreading, 10-45 mm long.

                     11 Corolla 13-25 mm long; leaves oval or oblanceolate

                     11 Corolla 5-14 mm long; leaves elliptic, rhombic-lanceolate, or lanceolate

                       12 Mid-stem leaves (6-) 7-13 (-18) mm long; proximal fruiting pedicels (5-) 7-17 (-22) mm long, (0.9-) 1-2 (-2.3) × as long as the subtending bracteal leaves; bracteoles shorter than to barely exceeding the sepals; [of granite outcrops in the GA Piedmont]

                       12 Mid-stem leaves (11-) 20-41 (-66) mm long; proximal fruiting pedicels (8-) 13-25 (-37) mm long, (0.3-) 0.5-1 (-1.6) × as long as the subtending bracteal leaves; bracteoles slightly to conspicuously longer than the sepals; [collectively of more habitats and more widespread].

                          13 Leaves narrowly elliptic or rhombic to oblanceolate, not conspicuously falcate, (2.7-) 5-11 (-18) mm wide, (2.5-) 3.5-5 (-6)× as long as wide; leaf margins with (1-) 3-5 (-7) teeth per side; primary veins 3-5 (-7); mid-stem moderately to densely glandular pubescent (rarely glabrate); seeds (0.18-) 0.22-0.26 (-0.29) mm thick; [widespread]

                          13 Leaves linear, linear-lanceolate, to elliptic-lanceolate, often falcate, (1-) 2.5-4 (-4.5) mm wide, (5.5-) 6-9.5 (-11)× as long as wide; leaf margins with 0-2 (-3) teeth per side; primary veins 1 (-3); mid-stem glabrous; seeds (0.19-) 0.26-0.32 (-0.37) mm thick; [limestone cedar glades of n. AL and c. TN]

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

    3 Plants erect herbs, not vining; [tribe Digitaleae]

    3 Plants vining; [tribe Antirrhineae].

      4 Calyx glandular-pilose; corolla lacking a raised palate (the raised area of lower lip)

      4 Calyx glabrous; corolla with a raised yellow palate (the raised area of lower lip)

  2 Corolla with a distinct spur or broad pouch protruding between the 2 lower calyx lobes; [tribe Antirrhineae].

        5 Corolla with a broad pouch at the base (saccate or gibbose).

          6 Calyx lobes about equal, all shorter than the corolla tube; corolla 25-40 mm long; leaves to 15 mm wide

          6 Calyx lobes distinctly unequal, all longer than the corolla tube; corolla 10-13 mm long; leaves to 5 mm wide

        5 Corolla with a slender spur at the base.

             7 Flowers in terminal racemes

             7 Flowers solitary in leaf axils.

               8 Stems erect; leaves linear

               8 Stems prostrate; leaves orbicular, ovate, or triangular.

                 9 Leaves orbicular in outline, palmately lobed and veined; stems rooting at nodes

                 9 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.

                   10 Leaves strongly basally disposed, usually all the leaves basal (or with significantly reduced cauline leaves); petals 3 or 4, scarious and translucent in texture or otherwise dull-yellow and inconspicuous; inflorescence a spike; [tribe Plantagineae]

                     11 Plants with leaves usually all basal; petals scarious and translucent in texture, not bilabiate; fruit a circumsessile dehiscent capsule (i.e. a lid-bearing pyxide); [collectively widespread]

                     11 Plants with prominent basal leaves and reduced, sub-whorled, cauline leaves; petals yellow, bilabiate; fruit a loculicidal capsule; [s. OH w. to s. IL, northward]

                   10 Leaves cauline, either opposite or whorled; petal 0, or 4, or 5; inflorescence various.

                       12 Leaves whorled.

                          13 Aquatic; leaves 5-30 mm long, lanceolate, toothed to deeply dissected into linear segments; [tribe Gratioleae]

                          13 Terrestrial; leaves 40-15 cm long, lanceolate or elliptic, toothed; [tribe Veroniceae]

                       12 Leaves opposite.

                            14 Petals 0; sepals 0, stamens 1; leaves both < 2 cm long and entire; [tribe Callitricheae]

                            14 Petals 4 or 5; sepals 4 or 5; stamens 2 or 4; leaves > 2 cm long, or serrate, or both.

                              15 Calyx and corolla 4-merous.

                                16 Leaves punctate; stamens 4; [tribe Gratioleae]

                                16 Leaves not punctate; stamens 2; [tribe Veroniceae]

                              15 Calyx and corolla 5-merous.

                                  17 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].

                                    18 Inflorescence compact, the inflorescence axis generally hidden by the closely packed and overlapping flowers; each flower subtended by large overlapping bracts

                                    18 Inflorescence more diffuse, the inflorescence axis readily visible between the flowers; flowers lacking extra subtending bracts

                                  17 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).

                                       19 Stamens 2; [section Gratioleae].

                                         20 Capsule turgid, roundish in ×-section; capsule longer than wide; leaves monomorphic; [collectively of many habitats and widespread].

                                           21 Flowers and fruits on definite pedicels; annual or perennial; leaves not papillose

                                           21 Flowers and fruits sessile or subsessile, the pedicels < 1 mm long; perennial; leaves papillose on the surfaces and margins

                                       19 Stamens 4.

                                             22 Sepals evidently connate into a tube about as long as the lobes; [section Cheloneae]

                                             22 Sepals distinct or very nearly so.

                                               23 Leaves deeply pinnatifid; [tribe Stemodieae]

                                               23 Leaves entire or toothed; [tribe Gratioleae].

                                                 24 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

                                                 24 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

1 Leaves peltate.

  2 Leaf blades oval in shape, ca. 1.5-2× as long as wide, at maturity floating on the water’s surface; underwater portions of fresh plant coated in transparent mucilage

  2 Leaf blades orbicular in shape, ca. 1× as long as wide, at maturity floating on the water’s surface, emersed, or submersed; underwater portions of fresh plant not mucilaginous (though possibly with green algae, etc.).

    3 Leaves small, < 8 cm in diameter, at maturity emersed or submersed

    3 Leaves large, > 20 cm in diameter, at maturity floating on the water’s surface or emersed

1 Leaves not peltate, the petiole attached at a cuneate, cordate, or sagittate base.

      4 Leaf blades cuneate, rounded, or truncate at the base.

        5 Basal leaves variously shaped, > 10 mm long.

          6 Main veins palmate from the leaf base and also diverging from the midvein, the secondary and tertiary veins then reticulating; inflorescence a spike; [Eudicots]

          6 Main veins either parallel or palmate from the leaf base with cross-veins at nearly right angles to the main veins; inflorescence either a diffuse raceme or panicle of white flowers, or a linear spadix of tightly packed golden-yellow flowers; [Monocots].

             7 Inflorescence diffuse, a raceme or panicle with whorled branches or pedicels, the flowers widely spaced and white; leaves green, “wettable”

             7 Inflorescence tightly packed with flowers, an elongate, golden yellow spadix; leaves blue-green, “unwettable”

      4 Leaf blades cordate or sagittate at the base.

               8 Leaf blades sagittate, the two lobes distinctly acute; leaf apex acute; leaf blade 1.3-3× as long as wide

               8 Leaf blades cordate, the two lobes rounded or sub-acute; leaf apex rounded or apiculate; leaf blade 0.8-8× as long as wide.

                 9 Leaf blade margins serrate, dentate, and/or incised

                 9 Leaf blade margins entire or obscurely crenate.

                   10 Flowers 4-5-merous (sepals 4-5, petals 4-5, stamens 4-5); [Eudicots]

                     11 Leaves emersed or submersed, on stout, stiff petioles (the submersed and winter leaves cuneate-based and lanceolate); flowers 4-merous (sepals 4, petals 4, stamens 4); inflorescence a spike

                     11 Leaves floating, on slender, flexuous petioles (all leaves cordate-based); flowers 5-merous (sepals 5, petals 5, stamens 5); inflorescence an umbel

                   10 Flowers 3-merous or many (>5-) -merous; [Basal Angiosperms or Monocots].

                       12 Perianth parts numerous (usually showing differentiation into sepals and petals, though often with some intergradation), borne in a spiral; stamens numerous; leaves usually > 10 cm long or > 10 cm wide, or both (a few northern species of Nymphaea with leaves as small as 2.5 cm × 2.5 cm); [Basal Angiosperms]

                       12 Perianth parts 3-6 (either differentiated or not into sepals and petals); stamens either 3, or 9-12 (-18), or >20; leaves 1-10 cm long, 1-10 cm wide; [Monocots].

                          13 Perianth strongly differentiated, the 3 sepals green, leathery, and persistent, the 3 petals yellow or white, delicate, deciduous; stamens 20 or more

                          13 Perianth not strongly differentiated, the sepals petaloid and similar in texture and color to the petals; stamens 10 or fewer.

                            14 Flowers unisexual, white, the sepals and petals separate; stamens 3, 6, 9, 12, 15, or 18; leaves either with a central area of spongiform cells (most easily seen on the lower leaf surface) (Limnobium), or without spongiform cells (Ottelia)

                            14 Flowers bisexual, white to blue, the perianth segments united below into a perianth tube 3-45 mm long; stamens 3; leaves lacking a central area of spongiform cells

1 Leaves whorled, most nodes with 3 or more leaves.

  2 Leaves strongly toothed to pectinate

  2 Leaves entire or finely toothed.

    3 Leaves tipped by a callus (visible at 10× magnification); leaf margins entire; flowers many, grouped in a terminal involucrate head; [Eudicots]

    3 Leaves not callus-tipped; leaf margins finely toothed or at least with conical protrusions remaining from the disintegration of better-developed deciduous teeth; flowers solitary on elongate, flexuous stalks; [Monocots]

1 Leaves opposite, no nodes with 3 or more leaves.

      4 Cauline leaves in 2-many nodes.

        5 Leaves in 2-3 pairs, appearing verticillate; plants of marine waters; [of FL, MS, LA and southward]

        5 Leaves along stem at 2-many nodes; plants of fresh to brackish waters; [collectively widespread].

          6 Flowers 3-merous; [Monocots].

             7 Leaf margins (or at least leaf sheaths) serrate or minutely spiny; fruits sessile, entire; leaves 5-15× as long as wide

             7 Leaf margins (including sheaths) entire; fruit stalked, dentate on one side; leaves >20× as long as wide

          6 Flowers 4- or 5-merous; [Eudicots].

               8 Leaves 1-12 cm long; flowers borne in axillary or terminal spikes or clusters

               8 Leaves 0.5-3 (-5) cm long; flowers solitary, axillary.

                 9 Carpels 4-5, separate; fruit an aggregate of follicles; leaves succulent

                 9 Carpels 2-5, fused; fruit capsular (variously dehiscent); leaves thin in texture or somewhat succulent (e.g. Bacopa in PLANTAGINACEAE).

                   10 Leaves dimorphic, the terminal leaves usually spatulate (strongly expanded towards the apex); corolla absent; stamen 1

                   10 Leaves monomorphic, obovate, oblanceolate, or parallel-margined; corolla present (absent in Didiplis in LYTHRACEAE); stamens 2-6.

                     11 Flower radially symmetrical, 3-4-merous; petals absent or separate

                       12 Stems lacking ridges running down from leaf bases

                       12 Stems with ridges running down from leaf bases

                     11 Flower bilaterally symmetrical, 4-5-merous; petals present, fused at least basally, forming a tube.

                          13 Corolla 4-merous

                          13 Corolla 5-merous