AMARANTHACEAE (AMARANTH FAMILY) 373 



nerved nor angled. Streets of Albany, New York City, and Brooklyn ; doubt- 

 less introduced, but the native habitat unknown. 



2. ACNIDA L. WATER HEMP 



Habit of Amaranthus. Bracts 1-3, unequal. Staminate calyx of 5 thin 

 oblong mucronate-tipped sepals, longer than the bracts ; stamens 5, the anther- 

 cells united only at the middle. Stigmas 2-5, often long and plumose-hispid. 

 Fruit somewhat coriaceous and indehiscent, or a thin membranous utricle 

 dehiscing irregularly (rarely circumscissile), usually 3-5-angled. (Name from 

 a- privative, and Kvid-rj, a nettle.) 



* Fruit indehiscent, with firm and close pericarp ; salt-marsh plants. 



1. A. cannabina L. Usually stout, 1-2 m. high or more, glabrous; leaves 

 lanceolate to linear-lanceolate, acuminate, long-petioled ; sepals of sterile flowers 

 ovate-oblong, obtuse or acutish ; bracts usually thin, lax, and much shorter than 

 the fruit, sometimes more rigid and longer ; fruit about 3 mm. long, obovoid ; 

 seed usually less than 3 mm. long, shining. (A. rusocarpa Michx.) Salt or 

 brackish marshes, coast of N. H. to Fla. 



* * Fruit dehiscing irregularly, the pericarp thin, loose and usually roughened; 

 not salt-marsh plants. 



2. A. tuberculata Moq. Tall and erect, with flexuous branches ; leaves 

 lanceolate to rhombic-ovate, acute or acutish ; sepals of sterile flowers lanceo- 

 late, acute or acuminate ; pistillate flowers closely clustered in more or less 

 dense naked or leafy axillary and terminal spikes (or the axillary capitate) ; 

 bracts rather rigid, acuminate, equaling or exceeding the fruit ; utricle about 

 1 mm. long ; seed shining, 0.7 mm. in diameter. (A. tamariscina, var. Uline & 

 Bray.) Vt. and Mass. (Ammidown) to Dak. and La. 



Var. subnuda Wats. Often decumbent ; leaves smaller, obtusish ; flowers 

 aggregated into distinct globose glomerules (7-15 mm. in diameter). (A. tama- 

 riscina, var. concatenata Uline & Bray, not A. cannabina, var. concatenata 

 Moq.) Sandy bottom lands, w. Que. to Wise, and Mo. Passing into the 

 typical form. 



Var. prostrata (Uline & Bray) Robinson. Prostrate, much branched; leaves 

 (1-2 cm. long, 3-10 mm. broad) and glomerules (4-6 mm. in diameter) small. 

 (A. tamariscina, var. Uline & Bray.) Similar situations, w. Que. to Minn., and 

 south w. 



* * * Fruit regularly circumscissile ; western. 



3. A. tamariscina (Nutt. ) Wood. With the habit of the preceding species 

 but readily distinguished by the fruit. {Amaranthus Nutt.) Prairies, etc., 

 " Dak. 1 ' to Tex. and N. Mex. ; said to occur as far e. as 111. 



3. CEL6SIA L. 



I 



Flowers subtended by a bract and two bractlets. Calyx scarious, in fruit 

 erect and (in our species) concealing the utricle. Stamens 5. Fruit a thin 

 inembranaceous utricle, circumscissile or dehiscing irregularly, ovoid or subglo- 

 bose. (Name from KiJXeos, a burning, on account of the seared appearance of 

 the flowers.) 



1. C. ARGENTEA L. Erect glabrous herb, 3-12 dm. tall ; leaves lanceolate, 

 short-petioled, acute ; inflorescence a simple dense cylindrical spike ; sepals 

 white or roseate-tinged, much longer than the bracts; style conspicuous, 

 exserted. Montgomery Co., Pa. (Porter}. (Adv. from the Tropics.) 



4. IRESINE P. Br. 



Flowers mostly polygamous or dioecious, 3-bracted. Calyx of 5 sepals. Sta- 

 mens mostly 5. Fruit a globular utricle, not opening. Herbs, with opposite 

 petioled leaves, and minute scarious-white flowers crowded into clusters or 



