Rhiu. ANACARDIACE^E. 109 



the edge of the disk, somewhat withering- persistent. Stamens 8 or 10, inserted at 

 the sinuses of the disk, shorter than the calyx : filaments subulate, persistent : 

 anthers didymous. Ovary one-celled, of a single ovoid carpel, with style extremely 

 short or none, and a depressed entire or obscurely 2-lobed stigma. Ovules 2, col- 

 lateral or nearly so, inserted on the ventral suture barely above the base of the cell, 

 ascending, obovate, anatropous. Fruit a firm-coriaceous follicle, ovoid, oblique, 

 acute, many-striate, opening down the ventral suture, 1 2-seeded. Seed obovate, 

 compressed, with a smooth crustaceous testa, in which on both sides is a small 

 bulging empty cavity ; a small arillus or caruncle at the hilum. Embryo or even 

 well-filled nucleus not seen. Low and rigid shrubs (of the interior arid region) ; 

 with slender spinescent branches, and small alternate simple and entire leaves, which 

 separate in age by an indistinct articulation from a dilated scale-like minutely 

 2-stipulate base ; the stipules adnate to the scale and setaceous-subulate ; flowers 

 small, solitary, terminating short axillary branches or spur-like fascicles : petals 

 white. PI. Wright, ii. 29, t. 12, & Proc. Am. Acad. xi. 73. 



1. G-. Nevadense, Gray, 1. c. Two or three feet high, much branched, pale or 

 slightly hoary with almost imperceptible pubescence : leaves oval, half an inch or 

 less in length, with short petiole abruptly terminating in the retuse broad stipulifer- 

 ous scale : calyx-lobes and petals 4 : stamens 8. 



Dry hills, Washoe Co., Nevada, Lcm.mon and Case, 1875. An interesting acquisition. 



G. SPINESGENS, Gray, the only other species, of New Mexico and Southern Utah, is smooth, 

 has smaller and narrower leaves and mostly 5-merous flowers. 



ORDER XXX. AJtf ACARDIACE.S!. 



Shrubs or trees (largely tropical or subtropical), with a resinous and usually acrid 

 juice, alternate leaves (either simple or compound) without stipules and almost 

 always not pellucid-punctate, and small regular flowers commonly polygamous or 

 dioecious ; the stamens as many or twice as many as the petals ; the free ovary in 

 the genuine representatives of the order 1-celled and 1-ovuled, but the styles often 

 3 ; the fruit drupaceous ; and the seed without albumen. 



A large order of nearly 50 genera, and 450 species, represented in California, as in the Atlantic 

 United States, only by the large and polymorphous genus Rhus. 



PISTACIA MEXICAXA, HBK., of Central Mexico, ranging to the valley of the Rio Grande, is 

 reported by Dr. Cooper as from San Diego. It is a small tree, with pinnate leaves ; leaflets 5 to 

 10 pairs, on a somewhat winged rhachis, oblong-obovate or cuneate, glabrate, half an inch long ; 

 flowers dioecious, without petals, in axillary or paniculate spikes ; stamens 5 ; fruit smooth, 2 

 lines in diameter, somewhat compressed. 



SCHINUS MOLLE, Linn., a native of Mexico and South America, is common as a cultivated 

 ornamental shrub in the southern part of the State, under the name of Pepper-tree or Chili 

 Pepper. It is an evergreen tree of moderate size, and very graceful habit ; leaves with 20 or more 

 pairs of lanceolate leaflets ; flowers small and dioecious, in large panicles, having 5 greenish petals 

 and 1 stamens ; drupes numerous, as large as a small pea, strongly pungent ; seed suspended 

 above the middle of the cell, instead of from a basal stalk as in most genera. The apparently 

 spontaneous movements of the leaves when placed in water are due to the bursting of the resinif- 

 erous glands with which they abound. 



1. RHUS, Linn. 



Sepals and petals (4 to 9) usually 5. Stamens as many or twice as many, with 

 subulate filaments, inserted under the edge of a disk lining the base of the calyx. 

 Fruit a small dry drupe. Seed pendulous upon a slender seed-stalk arising from 



