102 NORTH AMERICAN FLORA [VorumE 21 
Dimeianthus Raf, Fl. Tell. 3: 41. 1837. 
Amblogyna Raf. Fl. Tell. 3: 42. 1837. 
Euxolus Raf. Fl. Tell. 3: 42. 1837. 
Penirius Raf. Fl. Tell. 3: 42. 1837. 
Albersia Kunth, Fl. Berol. ed. 2. 144. 1838. 
Mengea Schauer, in Meyen, Nova Acta Acad. Leop.-Carol. 19: Suppl. 1: 405. 1843. 
Pyxidium Mog. in DC. Prodr. 132: 262. 1849. 
Sarratia Mog. in DC. Prodr. 13%: 268. 1849, 
Galliaria Bubani, Fi. Pyren. 1: 184. 1897. 
Annual herbs, erect or prostrate, glabrous or pubescent, usually branched. Leaves 
alternate, petiolate, entire or rarely sinuate-dentate, often mucronate. Flowers small, monoe- 
cious, dioecious, or polygamous, bracteate and bibracteolate, glomerate, the glomerules axillary 
or spicate or paniculate; sepals 5 or rarely 1-3, membranaceous, equal or subequal, sometimes 
indurate at the base after anthesis, erect in fruit. Stamens 5 or rarely 1-3; filaments filiform 
or sttbulate, distinct; anthers oblong or linear-oblong, 4-celled. Ovary ovoid, compressed; 
style short or wanting; style-branches 2 or 3, subulate or filiform, papillose or pubescent; ovule 
1, subsessile, erect. Utricle usually included in the perianth, compressed, indehiscent or cir- 
cumscissile or bursting irregularly, membranaceous or coriaceous, entire or 2-3-dentate at the 
apex. Seed erect, compressed, smooth; embryo annular, the endosperm farinaceous; radicle 
inferior. 
Type species, Amaranthus caudatus L. 
Sepals of the pistillate flowers spatulate, usually contracted into a narrow 
_claw at the base, more or less urceolate, at least in age, or, if not 
urceolate or spatulate, the flowers dioecious. 
Inflorescence of axillary, few- or many-flowered clusters; stems weak, 
ascending or prostrate. 
Pedicels and bracts much thickened and indurate. 
Utricle indehiscent; style-branches 2. 1, 
Utricle circumscissile; style-branches 3. 2 
Pedicels and bracts not thickened or indurate. 
Utricle circumscissile; leaf-blades suborbicular to obovate or oval, 
the leaves not crowded. 3. A. polygonoides. 
Utricle indehiscent; leaf-blades oblong-lanceolate, the leaves 
crowded at the ends of the branches. 4, A. Berlandieri. 
Inflorescence of terminal spikes but clusters of flowers usually present 
also in the axils of the leaves; stems stout, usually erect. 
Flowers dioecious. 
Utricle indehiscent. 
Plants prostrate or ascending; pistillate sepals greenish, 
spatulate. 
Sepals of the pistillate flowers rounded or obtuse at the 
apex, spreading from the middle, 3-3.5 mm. long; sepals 
of the staminate flowers 3 mm. long. 5. A. Greggii. 
Sepals of the pistillate flowers retuse, 2.2-2.9 mm. long, 
erect; sepals of the staminate flowers 2.3 mm. long. 6. 
Plants erect; pistillate sepals oblong, tinged with red. 7. 
Utricle circumscissile. 
Bracts 2-3 times as long as the pistillate calyx. 
Plants viscid-pubescent; leaf-blades obtuse to rounded at 
the apex. 8. A. Watsoni. 
Plants not viscid-pubescent; leaf-blades attenuate to 
acutish at the apex. 9. A. Palmeri. 
Bracts equaling or shorter than the pistillate calyx. 
Stems erect; leaf-blades oval-oblong to oblong-linear; 
bracts lanceolate; plants pale-green. 10. A. Torreyi. 
Stems spreading; leaf-blades oval to suborbicular; bracts 
ovate or broadly ovate; plants deep-green. 11. A. myrianihus. 
Flowers monoecious. 
Utricle indehiscent. 
Inflorescence narrow, spikelike, of numerous dense clusters; 
leaf-blades lanceolate to linear-oblong; sepals of the pistillate 
flowers 2 mm. long. 12, A. obcordatus. 
Inflorescence a broad panicle composed of numerous slender 
spikes; leaf-blades ovate or oblong-ovate; sepals of the 
. crassipes. 
. scleropoides. 
as 
. annectens. 
. ambigens, 
oe 
pistillate flowers 3 mm. long. 13. A. scariosus. 
Utricle dehiscent. 
Stamens 5. 
Bracts shorter than the pistillate perianth; leaf-blades 
obtuse. 14, A. chihuahuensis. 
Bracts longer than the pistillate perianth. 
Leaf-blades obtuse or retuse; inflorescence naked above. 15. A. lepturus. 
Leaf-blades acute; inflorescence leafy throughout. 16. A. Bigelovii. 
Stamens 2 or 3. 
