ABT 
gray scaly bark, 6 to 20 dm. high, with numerous slender divaricate 
branches: joints slender cylindrical, 6 to 7 mm. in diameter, covered 
with crowded and depressed-flattened 5- or 6-angled ashy gray tubercles 
5 to 6 mm. long: pulvini with wool, but scarcely bristly, unarmed or 
with a single (rarely double) elongated (3.5 to 5 em.) porrect or some- 
what deflexed spine (rarely a few additional minute ones), which is 
whitish and yellow to reddish and brown, and in a very loose yellow 
_ sheath (contracted at base and firmly adhering to the spine, loose and 
saceate above): flowers purple, 1 to2 em. broad: fruit ovate (contracted 
at base and apex), with narrow and deep umbilicus, dry and tubercu- 
late, bristly, 18 to 20 mm. long: seeds few, somewhat regular, with 
thick spongy margin, 3.5 to 4mm, broad. (Z1/, Pacif. Ry Rep. iv, t. 21, 
f, 1-7)—Type not found in the Engelmann collection. 
Deserts of the Colorado from southern Nevada through southeastern 
California and western Arizona into Sonora. 
Specimens examined: ARIZONA (Schott of 1856; Parry of 1867; Bis- 
choff of 1871; Palmer of 1876; Toumey of 1592, Yuma): CALIFORNIA 
(Parry of 1852; Bigelow of L854; Cooper of 1861; Wright of 1582; Parish 
Bros. 170 of 1882, San Bernardino Mts.; Zrelease of 1892): SONORA 
(Schott of 1855; Pringle of 1884, sandy plains, near Gulf of California). 
4 
The original name ramosissima (1852) was considered an unsuitable one in a section 
in which all the species are branching; it was therefore changed to tessellata (1856), 
referring to the curious crowded and angular flattened tubercles. The spines are 
crowded together at the upper end of each year’s growth, and these with their 
yellow shining sheaths surmounting very slender branches covered with scale-like 
tubercles give the plant a striking appearance. The spines have a wide range of 
coloration, since they may be not only whitish to vellow (the usual colors), but hav- 
ing always a yellowish tip, they may be ashy-gray or deep reddish-brown, or even 
black below or sometimes a combination of all of these colors. 
~** Stem erect but weak and using a support, branching and woody: spines none: 
flowers yellow. 
101. Opuntia rotundifolia Brandegee, Zoe, ti, 21 (1891). 
Erect and slender, weak and branching, 20 to 30 dm. high, supported 
by bushes, with a cylindrical woody stem only, 1 to 1.5 cm. in diameter: 
joints 6 to 10 cm. long, with fleshy round ovate leaves 2 to 3 em. long 
and wide: pulvini remote, with gray wool, numerous retrorsely barbed, 
usually reddish-brown, bristles 3 to 5 min. long, and no spines: flowers 
yellow, about 4 cm. broad: fruit slender-clavate, bristly, about 5 em. 
long and 4 to 6 mm. in diameter: seeds few, whitish and flattened, 
densely covered with white hairs (somewhat deciduous with age).— 
Type in Herb. Brandegee. 
“Not uncommon at low elevations in the Cape Region,” Lower Cali- 
fornia. 
Specimens examined: LOWER CALIFORNIA ( Brandegee of 1890, San 
José del Cabo). 
The specimens I have examined are presumably a part of the type material, 
They consist of naked terete stems 3 to 5 mm. in diameter, with the small tomentose 
