1 Plant erect or trailing (but not twining), herbaceous or woody.

  2 Plant a woody shrub, subshrub, or woody vine (trailing or climbing, but not twining).

    3 Leaves alternate.

      4 Fruit follicles; [waif]

      4 Fruit drupes; [native and non-native]

        5 Leaves lanceolate; corolla white, salverform, < 1 cm long; fruit white; [rare native, s. FL]

        5 Leaves linear; corolla yellow, funnelform, ca. 5 cm long; fruit green to brown; [non-native, s. TX and FL peninsula]

    3 Leaves opposite to subopposite or whorled.

          6 Plants armed, the stems with stout, bifurcated spines

          6 Plants unarmed, the stems without spines.

             7 Plant primarily trailing, rhizomatous, and suffrutescent, < 4 dm tall (usually becoming a "ground-cover"); leaves narrowly to broadly ovate; flowers blue, lavender, or white

             7 Plant erect, > 4 dm tall (2-5+ dm tall in Mandevilla, but plants not trailing and lacking rhizomes) or trailing and obviously woody (Allamanda, which has yellow flowers); leaves either lanceolate or elliptic (oblanceolate to obovate in Allamanda cathartica and Tabernaemontana); flowers yellow, white, pink, or red.

               8 Flowers white, pink, or red; shrubs or trees (shorter shrubs [2-5 dm tall] in Mandevilla; [non-natives, except Mandevilla].

                 9 Flowers cream-colored, long salverform (the floral tube 40-100 mm long and conspicuously pubescent); follicles long-fusiform and pubescent; leaf abaxial surfaces densely gray-white pubescent; plants short shrubs (2-5+ dm tall); [s. TX only in our area]

                 9 Flowers white, pink or red, if salverform the floral tube primarily glabrous and much shorter in length (2-12 mm long); fruit a drupe (Ochrosia) or rounded to long-fusiform follicle (if long-fusiform, then not conspicuously pubescent); [collectively widespread non-natives, including s. TX, but naturalizing primarily in FL]

                   10 Plants lianas or subshrubs, often at least somewhat climbing; latex milky; leaves opposite, not whorled; stipular colleters interpetiolar and intrapetiolar; follicles strongly 3-angled, fusiform, and paired on the stem

                   10 Plants erect shrubs or trees; latex milky or clear; leaves usually whorled (sometimes opposite, or predominantly so in Tabernaemontana); stipular colleters interpetiolar only; fruit (follicles or drupes) terete or 2-angled, if paired then conspicuously elongate-cylindric (Alstonia; Nerium)

                     11 Ripened fruit bright red or orange and fleshy (the interior at least bearing a fleshy red or orange aril in Tabernaemontana); latex milky.

                       12 Leaf apex obtuse to broadly acute; fruit a fleshy red drupe

                       12 Leaf apex acuminate or apiculate; fruit a yellowish-orange follicle with seeds bearing orange-red arils

                     11 Fruit conspicuously elongate-cylindric, brown or red-brown follicles (not drupe-like nor fleshy); latex milky or clear.

                          13 Plants trees, 2-60 m tall, with a single or multiple stem(s); latex milky; flowers white or cream colored, the anthers not connivent and not adhering to stigmas; follicles [uncommon non-natives, s. FL]

                          13 Plants shrubs, 10-40 dm tall, much branched from the base; latex clear; flowers white, pink, or red, the anthers connivent and adhering to the stigmas; [commonly cultivated in our area (and sometimes persistent), particularly near the coast; NC s. to FL, w. to TX]

               8 Flowers yellow; plants erect subshrubs 4-12 dm tall (Angadenia berteroi) or trailing to erect woody vines 0-20 m tall (Allamanda); [native or non-native].

                            14 Leaves oblanceolate, 15-40 mm wide, mostly in whorls of 3-4; plants larger trailing or erect woody vines; follicles rounded and spiny; [non-natives of disturbed habitats, c. and s. FL].

                              15 Lateral veins of the leaf blades not or only slightly raised on lower surface; seeds winged; corolla tube (below stamen insertion) 2-4 cm long

                              15 Lateral veins of the leaf blades prominently raised on lower surface; seeds not winged; corolla tube (below stamen insertion) 1.0-1.8 cm long

                            14 Leaves narrowly elliptic to oblong, 2.5-10 mm wide, leaves opposite; plants smaller subshrubs; follicles smooth; [native of pine rocklands and marl prairies, s. FL]

  2 Plant an erect (or primarily upright) herb or trailing herbaceous vine (occasionally subshrubs in Cataranthus).

                                16 Flowers with conspicuous or less conspicuous corona; follicles not paired; seeds with coma present.

                                  17 Leaves alternate, or sometimes whorled (e.g., A. verticillata), variously shaped, but not both petiolate and cordate; plant either an erect herb or a decumbent herb with stiff, thick stems (> 4 mm in diameter)

                                  17 Leaves opposite, petiolate and cordate, 2-4 cm long; plant a trailing herbaceous vine with weak, thin stems (< 2 mm in diameter)

                                16 Flowers lacking corona; follicles paired (occasionally single by abortion); seeds with coma absent (Catharanthus, Amsonia) or present (Apocynum).

                                    18 Leaves alternate (rarely a few on a plant subopposite)

                                    18 Leaves opposite.

                                       19 Flower < 8 mm across; paired follicles pendent, 10-22 cm long; seeds with coma; mature plants normally > 7 dm tall; plants herbaceous

                                       19 Flower > 20 mm across; paired follicles erect, 1.5-2.5 cm long; seeds lacking coma; mature plants 2-6 dm tall; plants herbaceous or sometimes subshrubs

1 Plant twining (the stems wrapping around another plant), herbaceous or woody.

                                         20 Leaves conspicuously cordate at base (or subcordate to truncate in Vinceotoxicum), ovate to broadly lanceolate, ca. 1-4× as long as wide.

                                           21 Plants in flower.

                                             22 Stem pubescence usually a mix of long eglandular and short, glandular-capitate hairs (the shorter hairs can be eglandular or glandular-capitate in Matelea); latex white; flowers variously colored: purple-black, maroon, brown, yellow, yellow-green, cream (white in Matelea baldwyniana); gynostegial corona < ½ as long as the corolla lobes.

                                               23 Corolla lobes glabrous on the outer surface; dorsal anther appendages laminar; follicles smooth and angled; leaves usually with a strong burnt popcorn or peanut butter smell when rubbed

                                               23 Corolla lobes glandular-puberulent or puberulent on the outer surface; dorsal anther appendages absent; follicles muricate (Matelea); leaves lacking a strong burnt popcorn or peanut butter smell when rubbed

                                             22 Stems glabrous, glabrate, or puberulent, if so lacking two distinct hair lengths and neither capitate-glandular (the puberulence either in conspicuous lines or of curved trichomes, often retrorse, and of similar length; latex white or clear; flowers primarily white or cream colored (except maroon in Vincetoxicum and occasionally reddish-maroon in Funastrum clausum); gynostegial corona > ¾ as long as the corolla lobes.

                                                 24 Corona with a conspicuous pentagonal ring present at the base of the staminal column (the structure apparent without dissection of flowers); latex white; stems glabrous or if pubescent, the trichomes curved (often retrorsely so)

                                                 24 Corona lacking a conspicuous pentagonal ring at the base of the staminal column; latex clear (except white in Cynanchum unifarium); stems glabrous to pubescent (if puberulent, often in lines).

                                                    25 Flowers primarily white (C. laeve) or cream-colored to yellowish or greenish-white (C. unifarium); corona a fleshy, lobed cup; stems puberulent in a single line (sometimes glabrate in C. unifarium); [natives, collectively widespread in our flora area]

                                                    25 Flowers light or dark maroon in color; corona not a fleshy cup, nearly as long as to longer than the corolla lobes; stem puberulence (including pedicels/peduncles) either distributed somewhat equally throughout stems or in decurrent lines from nodes; [non-natives, primarily northern and northeastern in our flora area]

                                           21 Plants in fruit.

                                                      26 Stem pubescence usually a mix of long eglandular and short, glandular-capitate hairs (the shorter hairs can be eglandular or glandular-capitate in Matelea); latex white; follicles muricate (studded) or smooth (sometimes ribbed, but lacking studs).

                                                        27 Follicles smooth, 5-angled but not conspicuously muricate; leaves usually with a strong burnt popcorn or peanut butter smell when rubbed

                                                        27 Follicles muricate (appearing studded); leaves lacking a strong burnt popcorn or peanut butter smell when rubbed

                                                      26 Stems glabrous, glabrate, or puberulent, if so lacking two distinct hair lengths and neither capitate-glandular (the puberulence either in conspicuous lines or of curved trichomes, often retrorse, and of similar length; latex white or clear.

                                                          28 Latex white; stems glabrous or if pubescent, the trichomes curved (often retrorsely so)

                                                          28 Latex clear (except white in C. unifarium); stems glabrous to pubescent (if puberulent, often in lines).

                                                            29 Stems puberulent in a single line (sometimes glabrate in C. unifarium); follicles ovoid to lanceolate-ovoid, (1.5-) 2.0-3.5 cm wide

                                                            29 Stem puberulence (including pedicels/peduncles) either distributed somewhat equally throughout stems or in decurrent lines from nodes; follicles fusiform to narrowly lanceolate-ovoid, ≤ 1 cm wide

                                         20 Leaves not cordate at base (cuneate, rounded, or truncate; occasionally hastate or subcordate); leaves ovate, lanceolate, or linear, ca. 1.5-10x as long as wide.

                                                              30 Leaves linear, the margins parallel.

                                                                 31 Leaves petiolate; calyx lobes deltoid, obtuse, ca. 1 mm long; leaves petiolate, not reflexed, often caducous; follicle 1-3 mm in diameter; [of se. SC and southwards]

                                                                 31 Leaves sessile; calyx lobes lanceolate, acute, (1.3-) 1.5-2.5 mm long; leaves sessile, reflexed, persistent; follicle 6-7 mm in diameter; [of ne. NC and southwards]

                                                              30 Leaves not linear, instead ovate, obovate, or lanceolate (rarely deltoid/rhomboid shaped).

                                                                   32 Flowers brownish-purple or maroon-colored.

                                                                     33 Stems herbaceous; corollas maroon-colored throughout, without green corolla margins; [widespread non-natives, ne. US]

                                                                   32 Flowers primarily white, whitish-green, creamy yellow, pure yellow, or light pink.

                                                                       34 Flowers with a gynostegial corona (crown-like structure), cream-white, greenish-white or pale pink colored (sometimes reddish-maroon in Funastrum crispum)

                                                                         35 Coronas in 2 whorls, with a conspicuous pentagonal ring present at the base of the staminal column (the structure apparent without dissection of flowers)

                                                                         35 Coronas in 1 whorl, lacking a pentagonal ring at the base of the staminal column (Leptadenia has an inconspicuous corona in 1 series that is ring-like, but the inner absent).

                                                                           36 Corolla lobes conspicuously pubescent on the upper (adaxial) surfaces; latex clear except only milky on developing fruit; [uncommon native, c. FL]

                                                                           36 Corolla lobes glabrous or if pubescent, not conspicuously so on the upper surfaces (usually confined to abaxial corolla lobe surfaces, if pubescent at all); latex white throughout; [native and non-natives, TX and FL]

                                                                              37 Corolla lobes 1.5-3.5 mm long (flowers smaller); leaves linear to ovate (but never hastate); plants with eglandular and minute glandular trichomes; [native of rocklands, woodlands, hammocks, pastures; TX and FL]

                                                                              37 Corolla lobes 7-13 mm long (flowers larger); leaves ovate, deltate, or hastate; plant with eglandular trichomes only; [non-native of disturbed habitats; FL]

                                                                       34 Flowers lacking a corona, white, creamy yellow or pure yellow colored.

                                                                                38 Corolla lobes 3-4 mm long, acute, reflexed, pale yellow; leaves subcoriaceous; [native, common]

                                                                                38 Corolla lobes 8-25 mm long, rounded, spreading, white OR yellow; leaves coriaceous (except Pentalinon, which has membranous to subcoriaceous leaves); [native or non-native].

                                                                                  39 Corolla campanulate (above short cylindric base, view flower from side), the lobes 8-12 mm long; [non-native]

                                                                                  39 Corolla salverform or funnelform, long and tubular (viewing flower from the side), the lobes 11-25 mm long; [native, c. and s. FL].

                                                                                    40 Leaf surfaces pubescent abaxially; flowers pure yellow; peduncles 20-40 mm long, sparsely pubescent

                                                                                    40 Leaf surfaces glabrous; flowers primarily white, sometimes creamy white with a tinge of yellow; peduncles 35-100 mm long, glabrous.

                                                                                      41 Leaf blades elliptic-ovate to orbiculate; calyx lobes 1.5-5.0 mm long, ovate to narrowly triangular; corolla lobes with a distinct limb; peduncles 35-60 mm long; follicles 5-7 mm wide, strongly divaricate; [typically occurring in rocklands, ocassionally in strands or marl prairies]

                                                                                      41 Leaf blades elliptic, oblanceolate, or oblong (rarely elliptic-obovate); calyx lobes 5-6 mm long, ovate; corolla lobes lacking a distinct limb; peduncles 75-100 mm long; follicles 3-4 mm wide, erect; [occurring in mangroves, swales, and similar coastal wetlands]