WOOTON AND STANDLEY—FLORA OF NEW MEXICO. 177 
8. PARIETARIA L. Pr ttrrory. 
Low annuals with alternate thin petioled entire leaves; inflorescence axillary, 
surrounded 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 ..........--..-2.20-2e ees cece e eee eee 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. Pl. 4: 955. 1806. 
TYPE Locality: Pennsylvania. 
Rance: 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. 8. 359. 1903. 
Tyre Locauity: Southern Utah. 
RanaeE: 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. HOUMULUS L. Hop. 
A climbing perennial herb; flowers dicecious, 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 Locauity: Beulah, New Mexico. 
Rance: Wyoming to New Mexico. 
New Mexico: Mountains west of Grant; Chama; Santa Fe and Las Vegas mountains; 
Sandia Mountains; Mogollon Mountains; Black Range; White Mountains. Thickets, 
in the Transition Zone. 
Order 21. SANTALALES. 
KEY TO THE FAMILIES. 
Leaves opposite; fruit a berry; tree parasites...... 38. LORANTHACEAE (p. 177). 
Leaves alternate; fruita drupe or nut; root parasites.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, dicecious; 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. Razoumorskya (p. 177). 
Berry globose, pulpy, semitransparent; anthers 2-celled; 
leaves usually large and foliaceous.............. 2. PHORADENDRON (p. 179). 
52576°—-15-—_12 
