APOCYNACEAE. 



[Vol. III. 



4. TRACHELOSPERMUM Lemaire, Jard. Fleur. i: pi. 61. 1851. 



Twining woody vines (some exotic species nearly erect shrubs), with opposite entire 

 deciduous leaves, and small yellow greenish or white flowers in terminal and axillary com- 

 pound cymes. Calyx small, deeply 5-parted, glandular within, the segments narrow. Cor- 

 olla funnelform or salverform, the tube nearly cylindric, expanded above, the lobes convo- 

 lute, more or less twisted. Stamens included, or short exserted; anthers sagittate, acuminate, 

 connivent around the stigma and slightly adherent to it. Disk of 5 glandular lobes. Ovary 

 of 2 carpels; ovules numerous in each carpel; style slender, its apex thickened below the 

 narrow ring of the ovoid stigma. Follicles much elongated, slender. Seeds linear, not 

 beaked, long-comose at the apex. [Greek, neck-seed, but the seed is not beaked.] 



About 6 species, natives of eastern Asia and North 

 America. The following is the only known North 

 American species. 



i. Trachelospermum difforme (Walt.) 



A. Gray. Trachelospermum. (Fig. 2899.) 



Echites difformis Walt. Fl. Car. g8. 1788. 

 Forsteronia difformis A. DC. Prodr. 8: 437. 1844. 

 T. difforme A. Gray, Syn. Fl. 2: Part 1, 85. 1878. 



A high-climbing vine, the stems Y^ in diameter 



or more, the twigs pubescent or glabrous. Leaves 



thin, ovate, oval or lanceolate, acuminate or acute 



at the apex, narrowed or rarely rounded at the 



base, 1 ^2 '-3' long, y z f -2' wide; petioles 2 // -4 // 



long; peduncles slender, shorter than the leaves; 



pedicels and branches of the cj me bracteolate at 



the base; flowers yellow or cream-color, 4 // -5 // 



long; lobes of the corolla ovate, spreading, shorter 



than the tube; follicles very slender, 5 '-9/ long, 



scarcely 1" thick. 



In moist woods and along streams, Delaware to 

 Florida, Texas and Mexico, mostly near the coast. 

 June-Aug. 



Family 18. ASCLEPIADACEAE Lindl. Nat. Syst. Ed. 2, 302. 1836.* 



Milkweed Family. 

 Perennial herbs, vines or shrubs, mostly with milky juice, with opposite 

 alternate or verticillate exstipulate leaves, and mostly umbellate perfect 

 regular flowers. Calyx inferior, its tube very short, or none, its segments 

 imbricated or separate in the bud. Corolla campanulate, urceolate, rotate 

 or funnelform, 5-lobed or 5-cleft, the segments commonly reflexed. A 5-lobed 

 or 5-parted crown (corona) between the corolla and the stamens and adnate to 

 one or the other. Stamens 5, inserted on the corolla, usually near its base; 

 filaments short, stout, mostly monadelphous, or distinct; anthers attached by 

 their bases to the filaments, introrsely 2-celled, connivent around the stigma, or 

 more or less united with each other; anther-sacs tipped with an infiexed or erect 

 scarious membrane, or unappendaged at the top, sometimes appendaged at the 

 base; pollen coherent into wax}'' or granular masses, one or rarely two such 

 masses in each sac, connected with the stigma in pairs or fours, by 5 glandular 

 corpuscles alternate with the anthers. Disk none. Ovary of 2 carpels; styles 

 2, short, connected at the summit by the peltate discoid stigma; ovules numerous 

 in each carpel, mostly anatropous, pendulous. Fruit of 2 several-many-seeded 

 follicles. Seeds compressed, usually appendaged by a long coma; endosperm 

 cartilaginous, mostly thin; embryo nearty as long as the seed; cotyledons flat. 



About 220 genera and 1900 species of very wide geographic distribution, most abundant in 

 tropical or warm-temperate regions. 



Erect or decumbent herbs. 



Corona-hoods each with an incurved horn within; leaves mostly opposite. 1. Asclepias. 

 Corona-hoods prominently crested within; leaves alternate. 2. Asclepiodora. 



Corona-hoods unappendaged or with a thickened crest-like keel; leaves opposite or alternate. 



3. Acerates. 

 Twining vines. 



Corolla-lobes erect; corona-lobes 1-2-awned. 

 Corolla rotate. 



Anthers tipped with a scarious membrane; pollen-masses pendulous. 

 Anthers merely tipped; pollen-masses horizontal. 



4. Ampelanus. 



5. Cynanchum. 



6. Vincetoxicum. 



* Text revised by Miss Anna Murray Vail. 



