164 CONTKIBUTIONS FEOM THE NATIONAL HEEBAEIUM. 



3. ALNUS Hill. Alder. 



Shrubs or small trees with thia toothed leaves; sterile catkins with 4 or 5 bract- 

 lets and 3 flowers upon each scale; fertile catkins ovoid or ellipsoid, the scales each 

 subtending 2 flowers and a group of 4 small scales, the latter becoming woody in 

 fruit, wedge-obovate. 



KEY TO THE SPECIES. 



Leaves rounded to truncate at the base, somewhat lobed, ovate to 



broadly oblong; stamens 4 1. A. tenuifolia. 



Leaves usually cuneate or at least narrowed at the base, seldom 

 lobed, the younger ones lanceolate, the older elliptic or ob- 

 long; stamens 1 to 3, usually 2 2. A.ohlongifolia. 



1. Alnus tenuifolia Nutt. N. Amer. Sylv. 1: 32. 1842. 



Type locality: "On the borders of small streams within the Range of the Rocky 

 Mountains, and afterwards in the valleys of the Blue Mountains of Oregon." 



Range: British America to California and New Mexico. 



New Mexico: Tunitcha Mountains; Cedar Hill; Chama; Santa Fe and Las Vegas 

 mountains. Along streams, in the Transition Zone. 



The powdered bark of the alder, together with ashes of JuniperiLS monosperma and 

 a decoction of Cercocarpus montanus, were used by the Navahos in preparing a 

 red dye for wool. 



2. Alnus oblongifolia Torr. U. S. & Mex. Bound. Bot. 204. 1859. 

 Alnus acuminata H. B. K. eiT. det. many authors. 



Type locality: Banks of the Mimbres and near Santa Barbara, New Mexico. 

 Type collected by Wright (no. 1864). 



Range: Southern Arizona and New Mexico. 



New Mexico: Magdalena Mountains; Mogollon Mountains; Black Range. Along 

 streams, in the Transition Zone. 



33. FAG ACE AE. Beech Family. 



1. QTIERCUS L. Oak. 



Low shrubs or large trees with rough bark on the older stems and hard tough wood ; 

 leaves chlorophyll green and deciduous, or bluish or grayish green and persistent 

 almost or quite until the appearance of the leaves of the following season, of various 

 shapes, size, and textiu-e, generally short-petioled, mostly more or less stellate- 

 pubescent at some time; flowers monoecious, the staminate usually in slender pendu- 

 lous aments, the pistillate solitary or in few-flowered spikelike aments, appearing 

 with the leaves; fruit (acorn) a nut varying in shape and size with the species, the 

 cup being also of varying size and shape. 



The treatment here given follows that of Doctor Rydberg,' and much of the work 

 was done in consultation with him, while examining a rather extended series of New 

 Mexican specimens. The species listed cover the material at New York and Wash- 

 ington and that in the herbarium of the New Mexico Agricultural College. With the 

 use of this material is combined the field experience of Doctor Rydberg and the 

 authors, extending over a number of years of careful study of the genus. 



The attitude here assumed is that forms represented by numerous individuals that 

 are easily distinguishable in the field and herbarium are worthy of separate names. 

 A\Tiether one calls them species or subspecies matters little; we prefer the former and 

 the forms are so treated here. 



1 The Oaks of the Continental Divide. Bull. N. Y. Bot. Gard. 2: 187. 1901. 



