272 ORDER 100. ASCLEPIADACE^E. 



n Crown double, the outer a ring, the inner 5-leaved. S. Fla S A RCOSTEMMA. 



N Crown simple, <c deeply 5-parted. Leaves linear SEDTKEA. \ 



x of 5 awned scales. Leaves ovate PERIPLOCA. 9 



x a ring 5-10-lobed, or merely wavy. . .(y) 



y Anther slits vertical, pollinia pendulous. Leaves thin VINCKTOXICUM. 7 



y Anther slits horizontal, pollinia spreading. Leaves cordate GONOLOBUS. 3 



y Anther slits vertical, pollinia erect. Leaves thick HOYA. 11 



1. ASCLEPIAS, L. MILK-WEED. SILK-WEED. Calyx and cor. segm. 

 soon reflexed. Staminal crown of 5 distinct hoods (cucullate leaflets), each 

 with a little curved horn from within. Anth. consolidated with the stig., 

 forming a 5-angled truncate mass (antheridium), opening by 5 chinks. 

 Pollen masses (pollinia) 5 pairs, hanging vertically by a pedicel from a cleft 

 gland. Follicles 2, lance-shaped, seeds comous. If Erect, with the flow- 

 ers in simple umbels which are between the petioles or terminal. Jn. Aug. 



* Flowers whitish, greenish, or purple in various shades. . .(a) 



* Flowers orange-colored or scarlet. Leaves narrowly lanceolate Nos. 25 17 



a Leaves ovate to lanceolate, narrowed to a petiole. ..(6) 



a Leaves ovate-oblong to cordate, sessile or clasping Nos. 1214 



a Leaves linear, very narrow. ..(x) 



b Both crown and corolla greenish-purple. Pods woolly-spiny Nos. 1, 2 



b Both crown and corolla pure purple. Pods smooth Nos. 3, 4 



b Crown white ; corolla white tinged with pink. Flowers small Nos. 57 



6 Crown white ; corolla greenish-white. c Umbels pedunculate Nos. 8, 9 



c Umbels subsessile. S Nos. 10, 11 



x Leaves all opposite, or rarely the highest alternate .Nos. 18, 19 



x Leaves mostly verticillate or scattered. Flowers greenish Nos. 20, 21 



1 A. Corn ii ti Dcsn. Leaves oblong-ovate, downy beneath, acutish at base and short- 



stalked, longer than the many-flowered umbels ; hoods ovate ; horns acute. Road 

 sides and hedges. 2 4f. Leaves 58'. Flowers 6". 



2 A. SiillIvantirEng. Leaves ovate-oblong, smooth both sides, nearly sessile, 



hoods obovate ; horns blunt ; flowers 9". Ohio to 111. July. 



3 A. purpurasccns L. Simple; leaves ovate to elliptical, acate mucronate ; um 



bels subsolitary. terminal ; peduncle 1 2' ; pedicels 1' ; _horns horizontal. N. Eng. 

 to N. Car., and W. 3 4f. Flowers large (6"), dark purple. Hoods lance-ovate. 



4 A. incarnata L. Branching above ; leaves lanceolate ; umbels many or few, some 



what panicled ; flowers small (3") : ped. 4 2'. Wet places. 3 5f: common. 

 ft. pulchra. Hairy ; leaves lance-oblong or -ovate. Very handsome, t 



5 A. ovalifolia Dcsn. Low, downy; Ivs. ovate, acntish; umbels subsessile, 10-15- 



flwd. ; pet. oval ; hoods yellowish, obtuse, longer than the horns. W. (A. Vaseyi C-B.) 



6 A pereniiis Walt. Branched at base, half-shrubby, smooth; leaves thin, lanceo- 



late, pointed both ways, long-stalked, exceeding the small white umbels; hoods 

 shorter than the horns. Low grounds, W. and S. 2f. (A. parviflora C-B.) 



7 A. q u ad ri folia Ph. Simple, smooth ; leaves ovate, acuminate, some of them in 



whorls of 4; umbels few, loose-flowered, long-stalked. Dry woods. 2f. 



8 A. variegata L. Simple, smoothish ; leaves oval to lance-oval, short-pointed, 



acute at base ; umbels densely QO-flowered. small (!' 18" diam.) ; hoods orbicular. 

 /3. nivta. LVP. elliptical, pointed both ways ; umb. 10-15-flwd. N. J., W. & S. 1 3f. 



9 A. pliytolaccoides Ph. Tall, simple; leaves broadly ovate, pointed both ways, 



glaucous ; umbels lateral, with about 20 drooping fls. ; peduncles and pedicels 1 3' 

 long ; hoods truncate, with 4 unequal teeth ; horns exserted. Damp shades. 4 5f. 



10 A. tomentosa Ell. Woolly, stout ; leaves lance-oblong, wavy, cuspidate ; umbels 

 lateral, with many large flowers; hoods obovate. truncate. Barrens. S. 



