114 NORTH AMERICAN FLORA [VoLume 21 
InLustRations: Willd. Hist. Amaranth. pl. 11, f. 21; Reichenb. Ic. Crit. pl. 475; Britt. & 
Brown, Ill. Fl. f. 1398; ed. 2. f. 1659; Iowa Geol. Sutv. Bull. 4: f. 64; Fiori & Paol. Ic. FI. Ital. 
f. 1046: Reichenb. Ic. Fl. Germ. 24: bl. 295; Moss, Cambr. Brit. Fl. ol. 154; Hegi, Ill. Fl. pl. 97, f. 
5; Clark & Fletcher, Farm Weeds Can. i. 42, 
28. Amaranthus dubius Mart. Pl. Hort. Erlang. 197. 1814. 
Amaranthus tristis Willd. Hist. Amaranth. 21, at least in part. 1790. Not A. tristisL. 1753. 
Amaranthus incomptus Willd. Enum. Hort. Berol. Suppl. 64, hyponym. 3, 
Amaranthus tristis xanthostachys Mog. in DC. Prodr. 13?: 260. 9, 
Amaranthus tristis flexuosus Moq. in DC. Prodr. 13?: 260. 1849. 
Amaranthus tristis leptostachys Moq. in DC. Prodr. 13?: 260. 1849. 
Amaranthus dubius xanthostachys Thellung, in Asch. & Graebn. Syn. Mittel-Eur. Fi. - a 1914, 
Amaranthus dubius flexuosus Thellung, in Asch. & Graebn. Syn. Mittel-Eur. Fl. 5: 266. 14. 
Amaranthus dubius leptostachys 'Thellung, in Asch. & Graebn. Syn. Mittel-Eur. Fl. 5: 366. 1914, 
Stems rather slender, erect, 3-10 dm. high, succulent, simple or mutch branched, green» 
glabrous, rarely pubescent about the inflorescence; leaves numerous, the petioles 2-9 cm. 
long, slender, the blades ovate or rhombic-ovate, 2-12 cm. long, 1.2-8 cm. wide, acute to 
rounded at the apex, the tip rounded and usually emarginate, rounded, obtuse, or acutish at 
the base, thin, deep-green, glabrous, or rarely pubescent when young, rather inconspicuously 
nerved; flowers monoecious, green or whitish, in slender, dense, terminal or axillary, simple or 
paniculate, usually drooping spikes 5-25 cm. long and 4-12 mm. thick, these often interrupted 
below, dense clusters of flowers sometimes present in the axils of the leaves; bracts ovate or 
oval, acute, scarious except for the midnerve and the pungent tip, usually shorter than the 
sepals but often equaling or rarely slightly exceeding them; sepals of the staminate flowers 
oblong-ovate or oval, acute or acutish, mucronate, 1-nerved, scarious; sepals of the pistillate 
flowers oblong to ovate, 1.5-2 mm. long, obtuse or acutish, often emarginate, mucronate, 
scarious, l-nerved, erect, distinct; stamens 5; style-branches 3, long and slender; utricle sub- 
globose, slightly longer than thick, not compressed, usually exceeding the sepals, thin-walled, 
slightly rugulose, dehiscent at the middle; seed rotund, 1 mm. in diameter, usually sharp- 
edged, dark reddish-brown or black, lustrous. 
Tyre LocALity: Described from cultivated plants. 
DisTRIBuTION: Common nearly throughout the West Indies; southwestern Mexico and Yuca- 
tAn; also in tropical South America; adventive in Europe 
ILLUSTRATIONS: Willd, Hist. Amaranth. pl. 5, f. 10; ‘Wight, Ic. pl. 514, 713. 
29. Amaranthus spinosus L. Sp. Pl. 991. 1753. 
Amaranthus diacanthus Raf. Fl. Ludov. 31. 1817. 
Amaranthus cavacasanus H. B. K. Nov. Gen. & Sp. 2: 195. 1817. 
Amaranthus spinosus rubricaulis Hassk. Flora 25: Litt. 20. 1842. 
Amaranthus spinosus viridicaulis Hassk. Flora 25: Litt. 20. 1842. 
Amaranthus spinosus purpurascens Mog. in DC. Prodr. 13*: 260. 1849. 
Amaranthus spinosus inermis Schum. & Laut. Fl. Deuts. Schutzg. Siidsee 305. 1900. 
eel spinosus circumscissus Thellung, in Asch. & Graebn. Syn. Mittel-Eur. Fl. 5: 269. 
Amaranthus spinosus basiscissus ‘Thellung, in Asch. & Graebn. Syn. Mittel-Eur. Fl. 5: 269, 1914. 
Amaranthus spinosus indehiscens Thellung, in Asch. & Graebn. Syn. Mittel-Eur. Fl. 5: 269. 1914. 
Galliaria spinosa Nieuwl. Am. Midl. Nat. 3: 278. 1914. . 
Stems stout and succulent, erect or ascending, 3-12 dm. high, glabrous below, more or 
less pubescent above, often reddish, striate or sulcate; petioles slender, 0.5-9 cm. long, often 
pubescent, bearing in the axils 2 rigid sharp-pointed spines 2-25 mm. long; leaf-blades ovate 
to rhombic-ovate or lanceolate, 1.5-12 cm. long, acute at the base, narrowed toward the apex 
but obtuse to broadly rounded at the tip, dark-green, glabrous or sparingly pubescent; flowers 
monoecious, the pistillate in dense, globose, sessile, mostly axillary clusters, the staminate in 
slender, erect or drooping, terminal spikes 3-18 cm. long and 4-8 mm. thick; bracts 
lanceolate to subulate, often spine-like, shorter than the sepals or sometimes 2~3 times as 
long; sepals of the pistillate flowers 5, oblong, obtuse or acute, 1.5 mm. long, those of the 
staminate flowers lance-oblong, acute or abruptly acuminate; stamens 5; style-branches 3; 
utricle ovoid, about equaling the sepals, irregularly and imperfectly circumscissile; seed smooth, 
black, lustrous, 0.7-1 mm. in diameter. 
