Flora of the Southeastern United States
2022 Edition

Colors

Data mode

Account

Login
Sign up

Click the number at the start of a key lead to highlight both that lead and its corresponding lead. Click again to show only the two highlighted leads. Click a third time to return to the full key with the selected leads still highlighted.

X
Keyed in multiple places:

Key to Rubiaceae

1 Trees, shrubs, or woody vines.
..2 Prostrate or climbing woody vine (liana), rooting at nodes; corolla lilac; [alien]; [subfamily Rubioideae; tribe Paederieae]
..2 Shrub or tree (sometimes somewhat scrambling, but not rooting at nodes); corolla white, green, maroon, or orange-red; [native or alien].
....3 Inflorescence spherical or globular; [collectively widespread]
......4 Fruits dry, dehiscent; [subfamily Cinchonoideae; tribe Naucleeae]
......4 Fruits fleshy, indehiscent; [subfamily Rubioideae; tribe Morindeae]
....3 Inflorescence cymose, thyrsoid, or corymbose; [Coastal Plain, from s. SC southward].
........5 Flowers orange-red; leaves usually whorled; [subfamily Cinchonoideae; tribe Hamelieae]
........5 Flowers white, green, or maroon; leaves opposite.
..........6 Flowers solitary, terminal; [subfamily Ixoroideae; tribe Gardenieae]
..........6 Flowers in cymose or thyrsoid inflorescences.
............ 7 Inflorescence cymose; some calyx lobes expanded into pink or reddish “flags”; leaves deciduous; domatia not present; [of s. SC southward]; [subfamily Ixoroideae; tribe Condamineeae]
............ 7 Inflorescences thyrsoid; calyx lobes inconspicuous; leaves evergreen; domatia present in secondary vein axils; [of ne. FL southward]
............ ..8 Lateral veins 3-6 on either side of the midvein; fruit white; petals yellowish, > 6 mm long; [subfamily Cinchonoideae; tribe Chiococceae]
............ ..8 Lateral veins 8-14 on either side of the midvein; fruit red; petals white, <5 mm long; [subfamily Rubioideae; tribe Psychotrieae]
1 Herbs (or creeping subshrubs in Mitchella).
............ ....9 Leaves whorled; [subfamily Rubioideae; tribe Rubieae]
............ ....9 Leaves opposite
............ ......10 Flowers paired, the ovaries connate and developing into a single fleshy red fruit; leaves roundish; creeping subshrub; [subfamily Rubioideae; tribe Mitchelleae]
............ ......10 Flowers single or in inflorescences with multiple flowers, the fruits either dry or fleshy and yellowish or black; leaves various; herb; [subfamily Rubioideae; tribe Spermacoceae].
............ ........11 Carpels with few to many seeds.
............ ..........12 Corolla 5-lobed
............ ..........12 Corolla 4-lobed.
............ ............ 13 Capsule longer than the calyx tube; flowers blue, pink, or white
............ ............ 13 Capsule not longer than the calyx tube; flowers white
............ ........11 Carpels 1-seeded.
............ ............ ..14 Flowers in dense, terminal, involucrate heads; flowers 4- or-6-lobed; styles 3
............ ............ ..14 Flowers in axillary or terminal clusters, or single in axils, not involucrate; flowers 4-lobed; styles 2.
............ ............ ....15 Flowers usually solitary in leaf axils; fruit separating into 2 parts.
............ ............ ......16 Sepals 4 and similar in size; style entire; [of dry habitats]
............ ............ ......16 Sepals 2 (or 4, and then markedly dimorphic); style cleft; [of moist to wet habitats]
............ ............ ....15 Flowers in terminal and axillary clusters; fruits not separating into 2 parts.
............ ............ ........17 Carpels opening transversely
............ ............ ........17 Carpels opening longitudinally

Key Q: herbaceous dicots with whorled leaves on the stem {add [Platycodon] CAMPANULACEAE}

1 Cauline leaves palmately compound.
..2 Cauline leaves essentially sessile, and also palmately cleft to the base, and further lacerately divided into linear or oblanceolate segments
..2 Cauline leaves petiolate, with 3-5, sessile or petiolulate, ovate, elliptic, or obovate leaflets (these serrate and sometimes with additional lobes).
....3 Inflorescence a spherical umbel of many flowers; fruit a drupe with 2-3 seeds; stem leaves 3-5
......4 Leaflets 3 (-5), sessile or subsessile, the petiolules 0-3 mm long; larger leaflets 4-8 cm long, 0.5-2.5 cm wide, averaging about 2.5× as long as wide, the apex obtuse to acute; fruit yellow-green when ripe, longitudinally winged and ribbed in ×-section; petals white (rarely tinged with pink); inflorescence nodding in bud; underground storage organ a spherical tuber
......4 Leaflets (3-) 5, petiolulate, the petiolules (7-) 10-25 mm long; larger leaflets 6-15 cm long, 3.5-7 cm wide, averaging about 1.8× as long as wide, the apex acuminate; fruit bright red when ripe, smoothly elliptical in ×-section; petals light green; inflorescence erect in bud; underground storage organ an +/- elongate root, this vertical or horizontal, and sometimes branched
....3 Inflorescence of single terminal flowers on the 1-several branches; fruit an aggregate of achenes; stem leaves 3
1 Cauline leaves simple.
........5 Inflorescence an involucrate head subtended by phyllaries, heads solitary or many, variously arrayed in secondary inflorescences; fruit a cypsela
........5 Inflorescence various, but not as above; fruit various, not as above (sometimes the flowers tightly grouped, but then with other features differing, such as stamens 4, or green calyx present, or fruit a schizocarp of mericarps, etc.).
..........6 Fruit a 3-lobed, 3-locular capsule; 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
..........6 Fruit various, not as above; inflorescence not a cyathium (and staminate or bisexual flowers almost always with > 1 stamen); fresh plants lacking milky juice.
............ 7 Leaves succulent, the terminal whorls closely juxtaposed; pistils 4-5; fruit an aggregate of follicles
............ 7 Leaves herbaceous, thin in texture, whorls separated; pistil 1, of 2-5 fused carpels; fruit a capsule, achene, or drupe.
............ ..8 Larger whorled leaves on a plant < 10 mm wide [some taxa keyed here and under the second lead].
............ ....9 Inflorescence a cymule, either axillary, or axillary and terminal; ovary inferior.
............ ......10 Leaves markedly variable in shape or size in each whorl; fruit a capsule; petals 5
............ ......10 Leaves similar in size and shape in each whorl; fruit dry or fleshy, indehiscent; petals (3-) 4
............ ....9 Inflorescence a terminal raceme, panicle, spike, cyme, corymb, or umbel; ovary superior.
............ ........11 Corolla bilaterally symmetrical, the petals connate; carpels 2; stamens 4, 6, or 8.
............ ..........12 Stamens 4; corolla blue or almost white
............ ..........12 Stamens 6 or 8; corolla pink or yellow
............ ........11 Corolla radially symmetrical, the petals separate; carpels 2, 3, or 5; stamens 5, 10, or many.
............ ............ 13 Inflorescence an axillary umbel; leaves narrowly linear and more than 10× as long as wide, > 20 mm long and < 2 mm wide; whorls of 3-6 leaves
............ ............ 13 Inflorescence a terminal cyme, raceme, panicle, or umbel; leaves as above, or broader in shape, narrower, or shorter; whorls of 3-16 leaves.
............ ............ ..14 Inflorescence a terminal cyme or umbel; corolla white; carpels 5.
............ ............ ....15 Leaves narrowly linear, 12-16 in each whorl; stamens 5
............ ............ ....15 Leaves ovate or obovate, 3 (-4) in each whorl
............ ............ ..14 Inflorescence a terminal raceme or panicle; corolla reddish, maroon, or yellow.
............ ............ ......16 Corolla reddish or maroon
............ ............ ......16 Corolla yellow
............ ..8 Larger whorled leaves on a plant > 10 mm wide.
............ ............ ........17 Inflorescence a spike; perianth absent; fruit a drupe
............ ............ ........17 Inflorescence various, but not a spike; perianth present; fruit various, but not a drupe.
............ ............ ..........18 Inflorescence of terminal involucrate clusters; perianth of 6 tepals; fruit an achene; stamens 9; [plants of very dry habitats]
............ ............ ..........18 Inflorescence various, but not as above; perianth of 2 whorls (the calyx often obsolete in Galium in RUBIACEAE), 3-, 4-, 5-, 6-, or 7-merous; stamens 2-7; [plants of dry-mesic to very wet habitats].
............ ............ ............ 19 Fruit dry or fleshy, indehiscent; petals (3-) 4; ovary inferior
............ ............ ............ 19 Fruit a capsule or follicle, dehiscent; petals 4-7; ovary superior.
............ ............ ............ ..20 Inflorescence an umbel; fresh plants with milky juice
............ ............ ............ ..20 Inflorescence not an umbel; fresh plants with clear juice.
............ ............ ............ ....21 Corolla pink-purple, 6-merous, the petals separate and borne on the edge of a hypanthium; stamens 8, 10, or 12; [plants of wetlands]
............ ............ ............ ....21 Corolla white, yellow, or greenish, 4-, 5-, or 7-merous, the petals fused at least basally into a tube (falling as a unit), not on a hypanthium; stamens 2, 4, 5, or 7; [plants of mesic habitats].
............ ............ ............ ......22 Stamens 2; corolla bilaterally symmetrical
............ ............ ............ ......22 Stamens 4, 5, or 7; corolla radially symmetrical.
............ ............ ............ ........23 Petals yellowish-white, with prominent green streaks; biennial or monocarpic plant, 10-30 dm tall when fertile; leaves 15-35 cm long
............ ............ ............ ........23 Petals white or yellow; perennial plants, 1-15 dm tall; leaves 1-15 cm long.
............ ............ ............ ..........24 Leaves punctate; stem without swollen nodes
............ ............ ............ ..........24 Leaves not punctate; stem with swollen nodes