130 BOTANY. 



to preserve and flowers and fruit have not often been found or collected. 

 Full notes, living joints, good fruit and seed, and pressed flowers are 

 desirable, to make us sufficiently acquainted with these plants. The best 

 method of preserving the flowers is to split them open before attempting to 

 dry them. Living plants or joints are very valuable, but alone are not 

 sufficient, because in cultivation they very rarely flower and scarcely ever 

 bear fruit. 



Opuntia (Cylindropuntia) clavata, Engelm. — A low, cespitose plant, 

 with short (1-3' high, 1' thick), clavate, ascending, strongly tuberculate 

 joints, the upper areolae bearing 4-7 ebony-white, flattened, striate spines, 

 surrounded by a number of smaller, bristly ones ; yellow flowers, 2' wide; 

 dry, yellow, oval pod, covered with numerous, large, woolly, and long-bristled 

 areola. — El Rito, New Mexico, Rothrock, in 1874 (92). Also about Santa 

 F6, etc. 



Opuntia (Cylindropuntia) pulchella, Engelm. (see Watson's Bot. 

 King's Expl. 119; Simpson's Report, Botany, t. 3). — A very small, purple- 

 flowered species of Nevada. A flower brought home by Mr. Bischoff was, 

 by a singular error, enumerated in the Catalogue of 1874 as Cereus viridi- 

 florus. 



Opuntia (Cylindropuntia) arborescens, Engelm. (see Watson, I. c. 

 120). — Cuero, New Mexico (101), Rothrock, in 1874; Cienega, South Arizona 

 (near Tucson), the same (584); and from Camp Bowie, Ariz. (1002), by 

 Mrs. Major Sumner. This handsome species extends northward to the 

 plains of Colorado and Pike's Peak, covering extensive tracts. Remark- 

 able for its horizontal, often whorled, branches ; purple flowers, 2-2£' in 

 diameter; ovary often with some spiny bristles, which at maturity disap- 

 pear. The skeleton, as the cactus wood is rather fancifully called after the 

 soft tissues have rotted away, forms a heavy, hollow cylinder, with regular 

 rhombic holes or meshes corresponding to the tubercles and spine-bunches 

 of the plant, and makes excellent canes. This species is closely allied to 

 the Mexican 0. imbricata and 0. decvpiens, arborescens being the northern, 

 larger-flowered form, but the seeds are different. 



Opuntia (Cylindropuntia) Bigelovii, Engelm. (Pac. R. R. Rep. 4, 



