APET'ALOUS TREES. 71 



PIPER AC E^E. 



Herbs with joinfed stems, alternate entire leaves and perfect flowers in spikes, en- 

 tirely destitute of floral envelopes. 



ANEMOPSIS, Hook, 



Flowers in a simple conical spadix, which is surrounded by a 5-8-leaved persistent 

 colored involucre, each flower subtended by a free colored bract. Stamens 6 to 8, free, 

 growing upon the immersed ovary. 



A, Californica, Hook. Stem simple, erect, 3 to 15 inches high, with a single broad, 

 clasping leaf in the middle, and an axillary branchlet reduced to 1 or more petioled 

 leaves; radical leaves oblong-oval, cordate at base, 2 to 6 inches long; involucre 1 to 1 

 inches broad, white, becoming brown. Used medicinally by the Mexicans, who call it 

 Yerba Mama. 



APETALOUS TREES. 



The Order Betulaceae (Birch Family) is represented in California by two Birches, 

 which scarcely attain to the dignity of trees, and are confined to the high Sierras, and 

 four Alders, two of which grow in the central part of the state, viz. : 



Alnus rubra, Bong. (Red Alder), and the more common 



Alnus rhombifolia, Nutt. (White Alder), which may be distinguished by its thinner 

 leaves, not rusty beneath, and more slender branches not so distinctly dotted with white. 



Myrica Californica, Cham. (Bayberry) representing the Order Myricacese, grows 

 in moist places, and may be known by its thick oblanceolate serrate evergreen leaves 

 and dense clusters of small fruit, whitened by a coat of wax. 



Umbellularia Californica, Nutt. (Order Lauraceae), is the well-known Laurel. 



Platanus racemosa, Nutt, is the California Sycamore. 



The Order Salicaceae is represented by 4 or 5 Willows, large enough to be called 

 trees, and 3 Poplars, viz. : 



Populus tremuloides, Michx. (Quaking Asp), a small tree, with whitish bark and 

 round ovate leaves. In the high Sierra. The only Calif ornian tree, except one of two 

 willows, found east of the Rocky Mountains. 



P. trichacarpa. Torr & Gr. (Cotton wood.) Petioles round; young bark brownish. 



P. Fremonti, Wat. (Fremont's cottonwood.) Petioles flattened; young bark yellowish. 



The WALNUT FAMILY is represented by Juglans Californica, the California Black 

 Walnut. 



About a dozen kinds of Oak Trees, and several shrubs of the same genus, with the 

 chestnut-like Chinquapin, represent the Order Cupuliferae. 



