WOOTON AND STANDLEY—FLORA OF NEW MEXICO. 163 
large rounded top 12 to 15 meters high. Its leaflets are broadly lanceolate, 6 to 9 
cm. long, not revolute-margined but serrate. The nut is 20 to 25 mm. in diameter. 
This species has been confused with a Californian one (J. californica S. Wats.) from 
which it is said, by those who know both, to be distinct. The Californian plant is 
found in the Sacramento Valley. 
Our native walnuts, this species in particular, are often known by the native name 
of ‘‘nogal.”’ 
Order 19. FAGALES. 
KEY TO THE FAMILIES. 
Staminate and pistillate flowers in aments; fruit never 
with a bur or cup.............. eee eee eee eee .. 32. BETULACEAE (p. 163). 
Staminate flowers in aments, the pistillate often soli- 
tary; fruit with a bur or cup................... 33. FAGACEAE (p. 164). 
32. BETULACEAE. Birch Family. 
Moneecious or rarely dicecious trees or shrubs with alternate simple leaves and 
deciduous stipules; sterile flowers in catkins; fertile flowers clustered, spicate, or in 
scaly catkins; fruit a 1-celled and 1-seeded nut with or without a foliaceous involucre. 
KEY TO THE GENERA. 
Ovary inclosed in a bladdery bag................. Lecce ee eeeeeee 1, Ostrya (p. 163). 
Ovary not inclosed in a bladdery bag. 
Stamens 2; bractsof the mature pistillate aments membra- 
nous, usually 3-lobed, deciduous with the nut ....... 2. Brruta (p. 163). 
Stamens usually 4; bracts of the mature pistillate aments 
thickened and woody, erose or toothed, persistent.... 3. ALNuS (p. 164). 
1. OSTRYA Scop. Hop HORNBEAM. 
A small tree; sterile flowers consisting of several stamens in the axil of each bract; 
fertile flowers a pair to each deciduous bract, inclosed in a bractlet, this in fruit 
becoming a bladdery bag, the involucres forming a kind of strobile resembling that 
of the hop. 
- 1. Ostrya baileyi Rose, Contr. U.S. Nat. Herb. 8: 293. 1905. 
TYPE LocaLiry: Guadalupe Mountains, Texas. 
Rance: Known only from the type locality. 
The type was collected only two miles from the New Mexico line, and the species, 
with but little doubt, occurs at the north end of the range in New Mexico. 
2. BETULA L. Bircu. 
Small tree or large shrub with slender stems; sterile flowers 3 to each shield-shaped 
scale of the catkin; fertile flowers 2 or 3 to each 3-lobed bract, the bracts thin, decidu- 
ous; fertile catkins ovoid to cylindric. 
1. Betula fontinalis Sarg. Bot. Gaz. 31: 239. 1901. 
Betula microphylla fontinalis Jones, Contr. West. Bot. 12: 77. 1908. 
TYPE LocaLiry: ‘‘On the Sweetwater, one of the branches of the Platte.’’ 
RanGE: British America to Colorado and New Mexico. 
New Mexico: San Juan Valley; Tunitcha Mountains; Paquate. Along streams, 
in the Upper Sonoran and Transition zones. 
