342 Trees of Southern California. [zoe 



trunk hardly a foot in diameter. Flowers often 8-10; pod viscid, 

 rough hirsute, and with some tack-shaped glands. Dry washes 

 of the Colorado Desert from Indio to the Colorado River. Mesquite 

 Canon, etc. Larger and more abundant in Arizona. 



Parkmsonia aaileatal^. "Hills of the Colorado, near Ft. 

 Yvimsi,. Schott." Torrey, Mex. Bound. 59. 



Parkinsonia microphylla Torr. " Colorado River, near Ft. 

 Yuma," Torrey, 1. c. These two species of Southern Arizona 

 have not been observed by recent collectors at the above station. 



Parkinsonia Torrey ana Wats. Straggling tree, 15 feet high, 

 trunk 10 inches in diameter. Fls. April. Frequent in dry 

 washes of the Colorado Desert from Toros to the Colorado 

 River; Indian Wells, etc. 



Prosopis juliflora DC. Straggling tree 20 feet high, usually 

 several stemmed from the base, or arborescent. In various kinds 

 of soil, but indicating a damp subsoil, and attaining its greatest 

 development in the desert. Fls. (at San Bernardino) May; Fr. 

 September. Throughout the entire desert region, scattered, 

 or rarel}', as at Indio, forming groves. As a shrub extending 

 as far west as San Bernardino, Temecula, and San Diego. 



Prosopis ptibcscens Benth. Arborescent shrub, 15 feet high, 

 with slender stem. Common, but less abundant than the last, 

 through the desert region, usually growing in ravines or the 

 borders of dry washes. W' hitewater; Warm Springs, etc. 



.Icacia Crcggii Gray. Armed shrub 2-10 feet high, form- 

 ing dense thickets of small extent, usually on dry hillsides. 

 Western border of the Colorado desert at 2000-3000 feet altitude; 

 San Gorgonio Pass; San Felipe. Also at Warner's Hot Springs, 

 within the intramontane district. 



Prjinns cmarginata Walp., var. vwllis Brewer. Arborescent, 

 the slender stems 10-15 f'^^t high, usually several clustered. 

 Leaves and stipules glandular toothed, lower surface of leaves 

 sparsely hirsute, peduncles and petioles tomentose with long, soft 

 hairs. Fls. June. Rare. Border of streams in ravines. Bear 

 Valley, 6000 feet altitude, San Bernardino Mountains. 



Pntnus dcsnissa Walp. Cerasns demissa Greene, Fl. Fr. 

 I. Shrub 2-6 ft. high, on hillsides, often in open patches. 



