FLORA OF THE DISTRICT OF COLUMBIA. 143 



6. PILEA Lindl. 



1. Pilea pumila (L.) A. Gray. Richweed. 



Moist, often alluvial soil; common. Aug. -Sept, Eastern N. Amer. (Adicea 

 pumila Raf.) 



7. BOEHMERIA Jacq. 



1. Boehmeria cylindrica (L.) Swartz. False nettle. 



Moist or wet soil; frequent. July-Oct. Eastern N. Amer. 



Boehmeria nivea (L.) Gaud., ramie, with leaves white-hairy beneath, was collected 

 in waste ground along the river front, Washington, Sept., 1899 (Steele). Native of 

 Asia; sometimes cultivated for ornament or for its fiber, rarely escaping in the U. S. 



42. LOEANTHACEAE. Mistletoe Family. 



1. PHORADENDRON Nutt. 



1. Phoradendron flavescens (Pursh) Nutt. Mistletoe. 



Rare in our region but more abundant eastward toward Chesapeake Bay, 'growing 

 on branches of Nyssa sylvatica and Acer rubrum. May- July, the white berries matur- 

 ing in late autumn. Southern states, north to N. J. 



43. SANTALACEAE. Sandalwood Family. 



1. COMANDRA Nutt. 



1. Comandra umbellata (L.) Nutt. Bastard toad-flax. 



Dry fields and woods; frequent. May- July. Eastern N. Amer. 



The plant is parasitic upon the roots of other plants. It is glabrous, more or less 

 glaucous, with oblong or elliptic, sessile, alternate, obtuse or acutish leaves, and 

 small white flowers in cymes. 



44. ARISTOIOCHIACEAE. Birthwort Family. 



Stems erect, slender; petioles shorter than the leaf blades, these ovate or ovate- 

 oblong, long-tapering at the tip; flowers very irregular 1. ARISTOLOCHIA. 



Stems prostrate, stout, rooting; petioles longer than the blades, these kidney-shaped, 

 broadly rounded at the apex; flowers regular 2. ASARUM. 



1. ARISTOLOCHIA L. 



1. Aristolochia serpentaria L. "» Virginia snakeroot. 



Dry woods; local. June- July. Eastern U. S. 



The deep purple flowers are borne on slender scaly branches at the base of the 

 plant. The roots are used in medicine. 



2. ASARUM L. 



1. Asarum canadense L. Wild ginger. 



Rich woods; common. Apr.-May. Eastern N. Amer. 



The rootstocks have the flavor of ginger. 



Material from our region has been referred to ^. re/?ermm Bicknell (A. oanadense 

 reflezum Robinson; A. reflexum. ambiguum Bicknell). That is supposed to differ from 

 A . canadense in having short calyx lobes about as long as the calyx tube ; in ^ . canadense 

 the calyx lobes are longer than the tube. A. reflexum, however, scarcely seems worthy 

 of specific rank. 



