394 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Flowers in crowded spikelike clusters, 
terminal or axillary, the pistillate 
usually below; petals small and 
inconspicuous, often wanting in 
the pistillate flowers, 
Stamens 10, monadelphous........- 10. Drraxis (p. 401). 
Stamens 6, the filaments distinct...11. Croton (p. 402), 
Petals wanting in all flowers. 
Stamens numerous, 8 to 20. 
Shrubs; stigmas 2-cleft............. 15. Bernarpta (p. 405), 
Herbs; stigmas dissected........... 12. ACALYPHA (p. 403). 
Stamens few, 2 to 5. 
Plants slender, small, covered with 
stinging hairs; capsules pedi- 
celed.............0.. ee eee ee 13, Traata (p. 404). 
Plants stout, much larger, glabrous; 
capsules sessile............... 14. Stiiiineta (p. 404), 
1. POINSETTIA Graham. PoInservria. 
Annuals, 30 to 60 cm. high, the stems simple or branched from the base; upper 
leaves often colored, alternate below, opposite above; stipules glandlike; involucres 
in axillary or terminal cymes or solitary, the lobes fimbriate; glands fleshy, solitary 
or rarely 3 or 4, sessile or short-stalked, without appendages, the missing ones repre- 
sented by narrow lobes; capsules exserted; seeds narrowed above, tuberculate or 
roughened. 
KEY TO THE SPECIES. 
Glands of the involucre sessile or nearly so; leaves discolored at 
the base; plants glabrous.........................222--- 1. P. havanensis. 
Glands of the involucre stalked; bracts and leaves not dis- 
colored; plants more or less pubescent. 
Leaf blades linear to linear-lanceolate; seeds not promi- 
nently tuberculate; glands of the involucre 3 or 4... 2. P. cuphosperma. 
Leaf blades ovate to ovate-lanceolate; seeds prominently 
tuberculate; glands of the involucre solitary. ....... 3. P. dentata. 
1. Poinsettia havanensis (Willd.) Small, Fl. Southeast. U. 8. 722. 1903. 
Euphorbia havanensis Willd.; Boiss. in DC. Prodr. 15?: 73. 1862. 
TYPE LOCALITY: Cuba. 
Rance: Southeastern United States to Arizona and in tropical America. 
New Mexico: Organ Mountains. 
2. Poinsettia cuphosperma (Engelm.) Small, Fl. Southeast. U. S. 721. 1903. 
Euphorbia dentata cuphosperma Engelm. in Torr. U. 8. & Mex. Bound. Bot. 190. 
1859. 
Euphorbia cuphosperma Boiss. in DC. Prodr. 15?: 73. 1862. 
Tyre Locauity: Copper Mines, New Mexico. Type collected by Wright (no. 
1834). 
RaNnGE: Wyoming and South Dakota to Texas. 
New Mexico: Upper Pecos River; Santa Rita; Organ Mountains; Roswell; White 
Mountains. Dry, open slopes, in the Upper Sonoran Zone. 
3. Poinsettia dentata (Michx.) Klotzsch & Garcke, Monatsb. Preuss. Akad. Wiss. 
Berlin 1859: 253. 1859. 
Euphorbia dentata Michx. Fl. Bor. Amer. 2: 211. 1803. 
TYPE Loca.ity: ‘‘Hab. in Tennassee.”’ 
