124 NORTH AMERICAN FLORA [VoruME 21 
III. CENTROSTACHYDEAE. Herbs or shrubs. Leaves opposite or 
alternate. Flowers perfect, polygamous, or dioecious; perianth-segments free, 
or united at the base. Stamens hypogynous, united at the base to form a 
short or elongate tube; anthers 4-celled. Ovary 1-ovuled, the ovule pendu- 
lous, the radicle superior. 
Flowers partly sterile, glomerate in the axils of bractlets, the tips of the peri- 
anth-segments of the fertile flowers usually uncinate. 8. CYATHULA. 
Flowers all fertile, each subtended by a bract and 2 bractlets. 9. CENTROSTACHYS. 
8. CYATHULA Lour. Fl. Cochinch. 101. 1790. 
Pubescent, branched, annual or perennial herbs.’ Leaves opposite, petiolate, the blades 
entire. Flowers fasciculate, each fascicle consisting of 1 or 2 perfect flowers and few or many 
sterile ones, the fascicles bracteate and bracteolate, spicate or capitate, reflexed in age; bracts 
concave, scarious, usually aristate; segments of the sterile flowers finally produced into elongate 
bristles, these uncinate at the apex; perianth of the perfect flowers scarious, 5-parted, the 
segments subequal, Il-nerved. Stamens 5; filaments united at the base; staminodia linear or 
quadrate and lacerate; anthers oblong, 4-celled. Ovary obovoid; style filiform; stigma capi- 
tate; ovule 1, suspended from the apex of an elongate funicle. Utricle included in the perianth, 
areolate at the apex, membranaceous, indehiscent. Seed inverted, oblong; embryo annular, 
the endosperm farinaceous; cotyledons plane, linear; radicle erect. 
Type species, Cyathula geniculata Lour. 
Sepals 2 mm. long; sterile segments 12-20, equaling the perianth. 1. C. prostrata. 
Sepals 3-4 mm. long; sterile segments 3-6, in age twice as long as the peri- 
anth,. 2. C. achyranthoides. 
1. Cyathula prostrata (L.) Blume, Bijdr. Ned. Ind. 549. 1826. 
Achyranthes prostrata L.. Sp. Pl. ed. 2.296. 1762. 
Cyathula geniculata Lour. Fl. Cochinch. 102. 1790. 
Desmochaeta prosirata DC. Cat. Hort. Monsp. 102. 1813. 
Pupalia prosirata Mart. Nova Acta Acad. Leop.-Carol. 13!: 321. 1826. 
Perennial, sometimes suffrutescent at the base, sparsely branched; stems slender, prostrate 
or ascending, 3-10 dm. long, geniculate, rooting at the nodes, the branches erect or ascending, 
angulate, sparsely hirtellous or puberulent, glabrate in age; petioles slender, 2-10 mm. long; 
leaf-blades rhombic-obovate, oblong-ovate, or oval, 2-7 cm. long, 1-4.5 em. wide, acute at the 
apex, rounded or acute at the base, thin, bright-green, shortly pilose-strigose on both surfaces 
or sometimes nearly glabrous, the blades of the lowest leaves often broadly oval or suborbicular 
and rounded at the apex; spikes terminal and axillary, 5-30 cm. long, 5-7 mm. thick, obtuse 
or acutish, much interrupted below, the rachis puberulent; bracts oblong-ovate, long-acuminate, 
glabrous, membranaceous, half as long as the flowers; bractlets triangular-ovate, half as long 
as the perianth, aristate-mucronate, villous; fertile flowers 2, the perianth-segments 2 mm. 
long, lance-oblong, acuminate, prominently nerved, villous, dull, green or purplish; segments 
of the sterile flowers 12-20, yellowish, about as long as the fertile flowers; staminodia short, 
oblong, bidentate at the apex; seed oblong, 1.2 mm. long, brownish, fuscous, lustrous. 
‘TYPE LOCALITY: India. 
DISTRIBUTION: Jamaica and Panama; probably adventive in America; also in Trinidad, 
Brazil, eastern and southern Asia, Africa, and the East Indies. 
ILLUSTRATIONS: Wight, Ic. pl. 733; Fawe. & Rendle, Fl. Jam. 3: f. 42. 
2. Cyathula achyranthoides (H. B. K.) Moq. in DC. Prodr. 
13?: 326. 1849. 
Desmochaeta achyranthoides H. B. K. Nov. Gen. & Sp. 2: 210. 1818. 
Desmochaeta densiflora H. B. K. Nov. Gen. & Sp. 2: 211. 1818. 
Desmochaeta uncinata R. & S. Syst. Veg. 5: 554. 1819. 
Achyranthes uncinata Willd.; R. & S. Syst. Veg. 5: =e assynonym. 1819. 
Achyranthes hirtiflora A. Rich. in Sagra, Hist. Cuba 11: 175. 1850. 
Cyathula prostrate achyranthoides Kuntze, Rev. Gen. 542. 1891. 
