WOOTON AND STANDLEY FLORA OF NEW MEXICO. 177 



3. PABIETARIA L. Pellitory. 



Low annuals with alternate thin petioled entire leaves; inflorescence axillary, 

 Burroiinded by an involucre of 2 to 6 more or less united bracts; achenes nearly terete. 



KEY TO THE SPECIES. 



Involucre 2 to 3 times as long as the flowers; stems simple or 



sparingly branched 1. P. pennsylvanica. 



Involucre about equaling the flowers or very slightly surpassing 



them; stems much branched at the base, stouter 2. P. obtusa. 



1. Parietaria pennsylvanica Muhl.; Willd. Sp. PI. 4: 955. 1806. 

 Type locality: Pennsylvania. 



Range : British America to Florida and Mexico. 



New Mexico: North Percha Creek; Sierra Grande. Damp ground, in the Upper 

 Sonoran Zone. 



2. Parietaria obtusa Rydb. in Small, Fl. Southeast. U. S. 359. 1903. 

 Type locality: Southern Utah. 



Range: Colorado and Utah to Texas and Arizona. 



New Mexico: Gila Hot Springs; mountains west of San Antonio; Organ Mountains. 

 Damp ground, chiefly in the Upper Sonoran Zone. 



37. CANNABINACEAE. Hemp Family. 



1. HUMULTJS L. Hop. 



A climbing perennial herb ; flowers dioecious, the staminate in loose axillary panicles, 

 the pistillate in short axillary spikes; bracts foliaceous, imbricated; leaves palmately 

 3 to 5-lobed ; fruiting calyx and other parts of the plant covered with yellow resinous 

 dots. 



1, Humulus lupulus neomexicanus Nels. & Cockerell, Proc. Biol. Soc. Wash- 

 ington 16: 45. 1903. 



Type locality: Beulah, New Mexico. 



Range : Wyoming to New Mexico. 



New Mexico: Moun tains west of Grant ;Chama; Santa Fe and Las Vegas moim tains; 

 Sandia Mountains; Mogollon Mountains; Black Range; White Mountains. Thickets, 

 in the Transition Zone. 



Order 21. SANTALALES. 



REY TO THE FAMILIES. 



Leaves opposite; fruit a berry; tree parasites 38. LOS,ANTHACEAE (p. 177). 



Leaves alternate; fruit a drupe or nut; rootparasites.39. SANTALACEAE (p. 181). 



38. LORANTHACEAE. Mistletoe Family. 



Evergreen plants parasitic on shrubs and trees, yellowish or brownish green ; branches 

 dichotomous, the joints swollen; leaves opposite, thick, entire, often reduced to con- 

 nate scales; flowers small and inconspicuous, greenish, dioecious; sepals 2 to 5; stamens 

 of the same number and inserted on the sepals; ovary inferior, 1-celled; fruit a berry 

 with a viscid endocarp. 



KEY to the genera. 



Berry compressed, fleshy, opaque; anthers 1-celled; 



leaves all reduced to connate scales 1. Razoumofskya (p. 177). 



Berry globose, pulpy, semi transparent; anthers 2-celled; 



leaves usually large and foliaceous 2. Phoradendron (p. 179). 



52576°— 15 12 



