210 



CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Anthers 2-celled; leaves opposite (mainly basal in 

 Gossypianthus) ; at least the younger parts of the 

 plant white-hairy. 



Pubescence of stellate hairs 3. Cladothrix (p. 213). 



Pubescence not stellate. 



Stems erect; fruiting calyx with spiny crests. . . 4. Froelichia (p. 214). 

 Stems decumbent or prostrate (except in one 

 species of Gomphrena); fruiting calyx 

 not with spiny crests. 



Stamens perigynous 8. Brayulinka i >. 216). 



Stamens hypogynous. 



Stems erect or decumbent; heads of 

 flowers pedunculate or terminal, 



large, 2 to 3 cm. in diameter 5. Gomphrena (p. 214). 



Stems prostrate; flower clusters sessile, 

 axillary, small, 1 cm. in diame 

 ter or less. 

 Staminodia wanting; cauline 

 leaves elliptic-lanceolate, 

 15 mm. long or less, appear- 

 ing as bracts subtending the 



flower clusters 6. Gossypianthus (p. 215). 



Staminodia present (shorter than 

 the filaments) ; cauline 

 leaves obovate-spatulate, 

 petiolate, 15 to 30 mm. 

 long, not bractiform 7. Alternanthera (p. 215). 



1. AMARANTHUS L. Amaranth. Pigweed. 



Rather coarse annuals; flowers monoecious or dioecious, with 5 or fewer hyaline or 

 greenish scalelike sepals, subtended by spine-tipped greenish or reddish bracts, 

 borne in axillary clusters or in terminal paniculately branched spikes; petals wanting; 

 stamens 5 or fewer; pistil solitary, with 2 or 3 styles; fruit a single-seeded indehiscent 

 or circumscissile pyxis. 



The leaves and seeds of the amaranths were formerly used for food by the Indians. 



key to the species. 



Flowers dioecious (in long terminal paniculate spikes). 



Bracts of the pistillate flowers much longer than the flowers, 



aristate-pungent 1. A. palmeri. 



Bracts of the pistillate flowers of the same length as the flowers, 



not pungent 2. A. torreyi. 



Flowers monoecious, in short, clustered, terminal or axillary spikes. 

 Sepals usually fewer than 5; plants low, usually spreading or 

 ascending; inflorescence mostly of axillary clusters. 

 Sepals 4 or 5; plants prostrate; seeds about 1.6 mm. in 



diameter 11. A. bliloides. 



Sepals 3; plants erect or spreading; seeds 0.8 mm. in 

 diameter. 



Plants glabrous or glabrate; leaves plane 12. A. graeeizans. 



Plants viscid-pubescent; leaves crispate 13. A. 



