AMARANTACE^. (AMARANTH FAMILY.) 429 



2. ACNIDA, Mitch. WATER-HEMP. 



Characters of Amarantus, except that the flowers are completely dioecious 

 and the pistillate ones without calyx. 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 plu- 

 mose-hispid. Fruit somewhat coriaceous and indehiscent, or a thin membran- 

 ous utricle dehiscing irregularly (rarely circumscissile), usually 3 - 5-angled. 

 (Name from a- privative, and wiSy, a nettle.) 



1. ACNIDA proper. Fruit indehiscent, with firm and close pericarp. 



1. A. cannabina, L. Usually stout, 2-6 high or more, glabrous; 

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

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

 shorter than the fruit, sometimes more rigid and longer; fruit about \" long, 

 obovate, the pericarp rather thin, more or less rugosely angled ; seed somewhat 

 turgid, not angled, usually less than 1" long, shining. Salt or brackish 

 marshes, coast of N. Eng. to Fla. 



2. A. rusocrpa, Michx. Very similar; fruit larger, l|-2" long, the 

 pericarp thicker, and the larger seed flattened with thick margins, usually 

 thickest on the cotyledonar side. N. Y. (?) and Penn. to S. Car. ; apparently 

 much less common than the last, though it is often difficult to positively dis- 

 tinguish the species from the immature fruit. 



2. MONTlSLIA. Fruit dehiscing irregularly, the pericarp thin, loose and usu- 

 ally roughened ; not salt-marsh plants. 



3. A. tuberculata, Moq. Tall and erect, or sometimes low and decum- 

 bent ; leaves lanceolate, acute or acutish or sometimes obtuse ; sepals of sterile 

 flowers lanceolate, 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, equalling or exceeding the fruit ' 

 utricle about -J" long; seed shining, j~" in diameter. (Montelia tamaris- 

 cina, Gray, in part.) Ohio to S. Dak., Mo., Ala., and La. 



Var. subntlda, Watson. Erect or often prostrate, the lower clusters at 

 least of pistillate flowers more or less cymose and often in globose heads ; bracts 

 thinner, narrow and lax, shorter than the fruit. (M. tamariscina, var. concate- 

 nata, Gray, in part.) W. Vt. (Oakes) ; Ont. to Minn., and southward. Often 

 appearing quite distinct from the type, but intermediate forms are not rare. 

 .1 



3. I BE SINE, P.Browne. 



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

 mens mostly 5 ; filaments slender, united into a short cup at base ; anthers 

 1 -celled, ovate. Fruit a globular utricle, not opening. Herbs, with opposite 

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

 spiked and branching panicles ; the calyx, etc., often bearing long wool (whence 

 the name, from elpecric&vr), a wreath or staff entwined with fillets of wool). 



1. I. celosioides, L. Nearly glabrous, annual, erect, slender (2-4 

 high); leaves ovate-lanceolate ; panicles very slender, often broad and diffuse, 

 naked ; bracts and calyx silvery-white, the fertile calyx twice longer than the 



