56 Flora of the Palouse Region 



A. rhombifolia Nutt. Tree 10-15 m. tall, with white bark, which on 

 older trees becomes broken into rectangular blocks: leaves ovate, elliptic or 

 obovate, mostly cuneate at the base and obtuse at the apex, glandular- 

 denticulate, finely puberulent on each surface, somewhat glandular beneath, 

 5-8 cm. long; petioles 1 cm. or less long: fruiting aments oblong-ovate, 2-3 

 cm. long, on short stout peduncles: nutlets broadly obovate, the margins 

 thickened. Banks of Snake River. 



A. sinuata Rydb. Small tree or shrub, 3-5 m. tall, erect or ascending: 

 bark rather dark, except in old stems: twigs chestnut brown: buds smooth, 

 gummy: leaves ovate, acuminate, obtuse orcuneate at the base, bright green, 

 doubly dentate, glabrous above, nearly so beneath, thin, very gummy when 

 voung, 5-8 cm. long; petioles slender, 1-2 cm. long: fruiting aments 1-1.5 

 cm. long, on slender longer peduncles. Thatuna Hills, along streams. 



A. tenufolia Nutt. Small tree, 5-10 m. tall: bark whitish even on the 

 twigs: buds pubescent: leaves ovate or somewhat obovate, mostly obtuse, 

 rounded or subcordate at the base, with small lobes at the end of each vein, 

 dentate-serrate, dull-green, 3-8 cm. long, sparsely pubescent on both sides, 

 becoming glabrous above; petioles stout, pubescent, 1-1.5 cm. long: fruiting 

 aments ovate, 1-2.5 cm - long, resinous. Along the South Fork below Pull- 

 man, and along the North Fork of the Palouse. 



Family 20. URTICACEAE. 



Herbs, shrubs or trees: leaves alternate or opposite, simple, 

 mostly stipulate: flowers small, monoecious, dioecious, polygamous 

 or perfect: calyx 2-9-cleft or 2-9 sepals: petals none: stamens 

 as many as the calyx-lobes and opposite them: ovary i-celled, 

 rarely 2-celled, mostly superior: ovule solitary: fruit a drupe or 

 akene (in ours); endosperm not copious, or scanty or none. 



Trees or shrubs: fruit a drupe. 86. CELTis. 

 Herbs: fruit an akene. 



Leaves opposite, with stinging hairs. 87. urTica. 



Leaves alternate, without stinging hairs. 88. parikTaria. 



86. CELTIS. 



Trees or shrubs: leaves serrate or entire, pinuately veined or 

 3 5-nerved: flowers polygamous or monoecious, borne in the axils 

 of this season's leaves, the staminate clustered, the fertile solitary 

 or 2-3 together: calyx 4 6-parted or of distinct sepals: ovary sessile; 

 stigmas 2: fruit an ovoid or globose drupe. 



C. OCCidentalis L-. Scraggly tree or shrub, 3-5 m. tall: leaves oblique- 

 ovate, acuminate, cuneate at the base, sharply serrate, pubescent when 

 voung, glabrous and shiny above when mature, somewhat pubescent on the 

 veins beneath, rough, reticulated, 4-8 cm. long; petioles about 1 cm. long: 

 fruit reddish, globose, smooth, 5-7 mm. in diameter, on slender peduncles, 

 about 2 cm. long. 



Basaltic bluffs on Snake River: a handsome tree when grown in good soil, 

 but under natural conditions very scraggly; leaves often distorted as a result 

 of insect attacks. 



