OF ARTS AND SCIENCES. 135 



tube: fruit not seen. — L. I'enosiis, var. obovatus, Turrey in racif. 11. 

 Rep. 4. 77. In the Sierra Nevada, in Calaveras County, where it lias 

 been collected by Bi^'elow, Brewer (n. 1G02, 1G12), Dr. G. L. Good- 

 ale, and II. Mann. Other specimens flora the Blue INlouniains, Ore- 

 gon (-Rev. R. D. Nevius), and from Northern Idaho (Geyer, n. .'512; 

 L. po/i/morp/iiis, Hook. Jour. Bot. G. 207), are probably the same, 

 with rather narrower and acuter leaflets. 



SornouA Auizonica. An evergreen shrub, somewhat canescent 

 with short appressed silky hairs : leaflets two or three paii's, nar- 

 rowly oblong, acutish, about an inch long ; stipules small, subulate : 

 racemes very short (half an inch long), and few-flowered; bracts de- 

 ciduous : pedicels bracteolate, about three lines long : calyx narrowed 

 at base : pods smooth, coriaceous, compressed, reticulated and with 

 nerve-like margins, three or four inches long, more or less contracted 

 between the thick oblong (half inch long) seeds ; stipe exceeding the 

 calyx. — S. speciosa, Torrey in Pacif. R. Rep*. 4. 82. At Cactus 

 Pass and on White Cliff Creek in W. Arizona, by Dr. Bigelow ; 

 only fruiting specimens found, January. The pod is thinner and more 

 compressed than is usual in the genus and the seed less globose. 

 The more eastern S. speciosa, Benth., has very thick and terete silky 

 pods, with ovate seeds, and larger obtuse or emarginate cuneate- 

 obovate or broadly spatulate leaves. 



Parkinsonia Torreyana. a small tree, twenty or thirty feet 

 high, with smooth light green bark ; younger branches and leaves 

 sparingly pubescent : leaflets two or three pairs in each pinna, oblong, 

 obtuse, narrower toward the somewhat oblique base, Iwo or three lines 

 long, glaucous : flowers on long pedicels in racemes terminating the 

 branches ; pedicels jointed near the middle, the joint not evident until in 

 fruit : petals appai'ently bright yellow, four lines long ; claw of the 

 upper petal with a thick prominent gland : ovary glabrous : pod with a 

 double groove along the broad ventral suture, usually two inches long 

 or more, 2— 8-seeded, straight or somewhat contracted between the 

 seeds : seeds very thick. — Cercidium jioridam, Torrey in Pacif. R. 

 Rep. 5. 360, t. 3. Abundant on the Lower Colorado River and in 

 the valleys of Western and Southern Arizona, and known as Palo 

 Verde or Green-barked Acacia. It has been always mistaken for 

 P. forida (^Cercidium Jloriduin, Benth.), of the Rio Grande Valley, 

 which has sessile axillary racemes, pods with a narrow acute margin 

 on the ventral side, thinner'seeds, and somewhat smaller leaflets. 



The characters which have been relied upon to sepaiate Cercidium, 

 Tulasne, from Parkinsonia, do not hold good in regard to our western 



