174 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
the deciduous-leaved species, being frequently more than 10 cm. long and half as 
broad. They are of a rich dark green and glabrous on the upper surface and much 
paler beneath. In outline the leaves are broadly elliptic-obovate, deeply pinnate- 
lobed, the rounded, open sinuses reaching three-fourths the way to the midrib. The 
lobes are broadly oblong to triangular, rounded toward the acute or obtuse apex, and 
many of them bilobate. The acorns are large, with hemispheric cups having mod- 
crately thickened scales, 
A queer form which seems to be most nearly related to this species is shown in 
Standley’s 4755 from Winsors Ranch, where it is common on rich hillsides. The 
leaves are divided to within 2 or 3 mm. of the midrib, the segments reduced in num- 
ber and size; in a few cases the leaf is reduced to a long-oblanceolate form less than 1 
cm, wide at the obtuse tip, without lobes of any kind. 
24. Quercus gambelii Nutt. Journ. Acad. Phila. II. 1: 179. 1848. GAMBEL OAK. 
Quercus douglasii gambelia A. DC. in DC, Prodr. 16?: 23. 1864, in part. 
Quercus undulata gambelii Engelm. Trans. Acad. St. Louis 3: 382. 1876. 
Type LocaLity: Banks of the Rio Grande, New Mexico, west of Santa Fe. Type 
collected by Gambel. 
Rance: Mountains of northern New Mexico and southern Colorado. 
New Mexico: Chama; Tierra Amarilla; Canjilon; Santa Fe and Las Vegas moun- 
tains; Johnsons Mesa; Sandia Mountains; Zuni Mountains; East View. At middle 
elevations, in the Upper Sonoran and Transition zones. 
The original description of this species applies to a shrubby, deciduous, green- 
leaved oak with an acute acorn, from the region of Santa Fe. Such an oak is to be 
found in that region, although it is by no means the common form. Most of the de- 
ciduous, green-leaved oaks of New Mexico and Colorado have obtuse or truncate 
acorns, and are to be found listed here under other names. If one were to consider 
all the white oaks of the State as belonging to a single species, it should be called Q. 
gambelii; but there are numerous easily recognizable variants of that type and our 
judgment as to their proper recognition is expressed in this treatment. 
Order 20. URTICALES. 
KEY TO THE FAMILIES. 
Fruit a samara or drupe, sometimes nutlike......... 34, ULMACEAE (p. 174). 
Fruit an achene. ‘ 
Flowers on the outside or inside of a recepta- 
cle; fruits forming syncarps; sepals ac- 
crescent, enveloping the achenes...... 35. MORACEAE (p. 175). 
Flowers not on a receptacle; fruits not forming 
syncarps; sepals neither thick and juicy 
nor enveloping the achenes. 
Style or stigma 1; ovule erect; filaments 
inflexed in the bud................ 386. URTICACEAE (p. 176). 
Styles or stigmas 2; ovule pendulous; fila- 
ments erect in bud.......---.--.... 387. CANNABINACEAE (p. 177). 
34. ULMACEAE. Elm Family. 
1. CELTIS L. Hackserry. 
A small tree or large shrub; leaves ovate or ovate-lanceolate, abruptly acuminate, 
reticulate, cordate and very unequal at the base; flowers greenish, axillary, the 
fertile solitary or in pairs, appearing with leaves; calyx 5 or 6-parted, persistent; 
stamens 5 or 6; ovary 1-celled, with a single ovule. 
