AMAEANTHACEAE. 45 



iy€ 1. A. polygonoides L. Stem and branches 1-5 dm. long: leaf -blades rhombic, 

 ovate or oval, 1-2 cm. long: staminate calyx 0.9-1 mm. long: pistillate calyx 

 2.2-2.4 mm. long; sepals narrowly cuneate. — Hammocks and open sandy places, 

 U. keys, L. keys. — (Bah., Cuba, Ant.) 



n ' 2. A. hybridus L. Stems 5-25 dm. tall, not spiny : leaf-blades ovate to ovate- 

 lanceolate or elliptic, 3-12 cm. long: staminate calyx 1.7-1.9 mm. long: pistil- 

 late calyx 1.7-2 mm. long; sepals narrowly oblong to oblong-lanceolate. — 

 Waste places and cultivated grounds, Key West. — {Ber., Bah., Cuba, Ant.) 



/^%3. A. spinosus L. Stems 2-12 dm. tall, spiny: leaf-blades ovate, rhombic- 

 ovate, or lanceolate, 1.5-8 cm. long: staminate calyx 2-2.7 mm. long: pistil- 

 late calyx 2-2.5 mm. long; sepals broadened upward, abruptly pointed. — Pine- 

 lands and cultivated grounds, U. keys, L. keys. Nat. of Trop. Am. — [E. K.] 

 — (Bei:, Bah., Cuba, Ant.) — Thorny- amaraxth. 



/7i 4. A. gracilis Desf. Stems 2-9 dm. tall: leaf -blades ovate or rhombic, 2-6 cm. 

 long: staminate calyx 1.3-1.5 mm. long: pistillate calyx 1.4-1.6 mm. long; 

 sepals broadened upward, and mucronate. — Hammocks and cultivated grounds, 

 L. keys, L. S. keys. — (Bah., Cuba, Ant.) 



/"-S. A. crassipes Schlecht. Stem and branches 1-6 dm. long, stout: leaf -blades 

 spatulate to ovate, 1-2.5 cm. long: staminate calyx 1.9-2.2 mm. long: pistillate 

 calyx 1.7-2 mm. long; sepals spatulate, abruptly pointed: ovary tuberculate. — 

 Hammocks and waste places, L. keys. — (Bah., Cuba, Ant.) 



3. ACNIDA L. Herbs, mostly annuals and large. Leaves alternate: 

 blades entire. Flowers dioecious, the spike sometimes interrupted, the stami- 

 nate with 5 sepals and 5 distinct filaments, the pistillate flowers without a 

 perianth. 



/•}S 1- A. cuspidata Bertero. Stems 1.5-7 m. tall, widely branched : leaf- 

 blades lanceolate to elliptic-lanceolate, 10-30 cm. long: staminate calyx about 

 2 mm. long; sepals oblong to oblong-ovate, mostly obtuse: pistillate calyx 

 1.7-2 mm. long; sepals lanceolate: utricles 1-1.5 mm. long. — Low hammocks 

 or cultivated grounds, L. keys, L. S. keys. — [E. K.] — (Ant.) — Water-hemp. 



4. ACHITRANTHES L. Herbs or woody plants. Leaves opposite: 

 blades entire. Flowers perfect, in slender elongate spikes, commonly de- 

 flexed. Sepals 4 or 5, becoming firm. Stamens 5 or rarely fewer. Styles 

 "united. 



/^^ 1. A. indica (L.) Millsp. Plants 4-12 dm. tall, finely pubescent: leaf -blades 

 broadly rhombic-ovate to obovate or cuneate, 1-3 cm. long, truncate or retuse 

 at the apex, and abruptly tijsped: bracts 2.5-3 mm. long, long-acuminate: 

 sepals lanceolate, 3-4 mm. long: utricle with a sharp rim at the top, about 2 

 mm. long. — Cultivated grounds and waste places. Key West. Nat. of Asia. — 

 (Bah., Cvba, Ant.) 



5. ALTERNANTHERA Forsk. Herbs (ours perennial). Leaves oppo- 

 site: blades entire or nearly so. Flowers perfect, in head-like spikes. Sepals 

 5, unequal. Filaments united at the base. Staminodia sometimes surpassing 

 the anthers. Styles united. 



Staminodia shorter tlian tlie filaments. 



Stems pubescent : sepals awn-tipped : staminodia entire or nearly so. 



i. A. repens. 

 Stems glabrous or nearly so : sepals not awn-tipped : stami- 

 nodia copiously toothed. 2. A. polygonoides. 

 Staminodia as long as the filaments or surpassing them. 



Spikes sessile or nearly so : calyx sessile : sepals unequal 



in length. 3. A. maritima. 



