424 
The above description was drawn up by Dr. Engelmann from the Agassiz material. 
Brandegee’s specimens supply a good joint, a flower, and ripe fruit, enabling me to 
supplement the description, The joint is 22 by 14 cm., the pulvini very large and 
prominent and close together, sometimes even in contact. The fulyous wool gradu- 
ally becomes darker until it is black, and encircling it above there is usually a more 
or less prominent tuft of bright-yellow bristles. The single withered flower is small 
and greenish yellow, The fruit is evidently juicy, globose or obovoid, strongly 
tuberculate, closely set with the pulvini bearing dark wool, and yellow bristles and 
spines, about 4.5 em. in diameter, The seeds are discoid and beaked, somewhat irreg- 
ular, with thick margin, 3 to 3.5 mm. broad. The spines are terete. 
17. Opuntia pycnantha margaritana, var. nov. 
Pulvini not so prominent, with more grayish wool, reddish bristles, 
dark-red more rigid and more or less angular and compressed spines.— 
Type in Herb. Brandegee. 
Santa Margarita Island. 
Specimens examined: LOWER CALIFORNIA (Brandegee of 1889), 
Mr. Brandegee also notes that the flowers are red. 
ii, Stem procumbent. 
18. Opuntia procumbens Engelm. Syn. Cact, 292 (1856). 
Prostrate, with the large pale-green orbicular-obovate joints always 
on edge, 15 to 30 em. long by 15 to 22 em. broad: pulvini 2.5 to 5 em, 
apart, with long (3 cm.) tomentum, yellow rigid strongly unequal bris- 
tles, and 2 to 5 (sometimes 7 to 9) compressed-angular unequal detlexed 
spines | to 5 cm. long (lower ones shortest) and straw-color or paler, 
darker towards the base, often reddish or reddish-brown: fruit ovate, 
3.5 cm. long: seeds 3 to 4mm, in diameter, with broad irregular mar- 
gins. (ll. Pacif. R. Rep. iv, t. 7, f. 4,5).—Type, Bigelow of 1854 in 
Herb. Mo. Bot. Gard. 
In rocky places, from El Paso, Texas, to northwestern Arizona. 
Specimens examined: ARIZONA (Bigelow of 1854): Texas (Evans of 
1891, K] Paso). 
The original Arizona range is ‘‘from the San Francisco Mountains to Cactus Pass 
at head of Bill Williams River.” The El Paso specimens are smaller than the more 
western ones, but otherwise there seems to be no difference, 
19. Opuntia rubrifolia Engelm,. MSS. 
Prostrate, with thick ovate joints 12 to 15 em. long by 10 em. broad, 
not tuberculated: leaves spreading, somewhat recurved, reddish, 8 to 
10 mm, long: pulvini 2 to 2.5 em. apart, with brownish-gray persistent 
wool and numerous yellowish bristles (especially on the upper edge): 
spines at lower edge of pulvinus, mostly 2 or 3, slender, angular, and 
often twisted, 2.5 to 6 cm. long, often a few additional smaller ones, 
all detlexed (almost appressed): flowers and fruit unknown.—Type, 
Palmer 3 in Herb. Mo. Bot. Gard. 
St. George, Utah. 
Specimens examined: UTau (Palmer 3). 
