90 
THE CACTACEAE. 
Echinocactus lindleyi Forster, Hamb. Gartenz. 17: 162. 1861. 
Nearly globular or a little broader than high, 7.5 cm. high; ribs 12, broad, rounded; areoles 1.5 
cm. apart; spines yellowish brown at first, but in age only the tips brown; radial spines 9 to 11, 
spreading, 1.5 to 2 cm. long; central spines 2, the longest 3 to 3.5 cm. long. 
Type locality: Probably Peru. 
Its flowers were unknown when described and it has disappeared from collections 
although it is said to be very ornamental. It was referred to Salm-Dyck’s group, Cepha- 
loidei, to which most of the species of Copiapoa were referred. 
Echinocactus pyramidatus Forster, Hamb. Gartenz. 17: 162. 1861. 
Short-pyramidal, about 18 cm. high, 13 cm. in diameter; ribs 15; areoles 4 to 6 mm. apart; 
spines stiff, reddish brown; radial spines 8; central spines 3, 3 to 3.5 cm. long, stout; flowers yellow. 
Type locality: Probably Peru. 
5 . PEDIOCACTUS Britton and Rose in Britton and Brown, Illustr. FI. ed. 2. 2: 569. 1913. 
Globular, single or cespitose, small, strongly tubercled cacti; tubercles borne on spiraled ribs; 
young areoles very woolly, but in age nearly naked; flowers small, with a rather indefinite funnel- 
shaped tube, pinkish, broadly campanulate; outer perianth-segments smaller than the inner and 
duller in color; inner perianth-segments oblong, numerous; scales on flower-tube few, naked in their 
axils; stamens numerous; ovary green, nearly globular, with a few scales towards the top, and a 
depressed scar at apex; fruit dry, greenish, splitting on one side; seeds dull black, tuberculate, 
keeled on the back with a large sub-basal hilum. 
Type species: Echinocactus simpsonii Engelmann. 
The plant has been described both as a Mammillaria and as an Echinocactus. In 
its globular shape and strongly tubercled surface it resembles very much many of the 
so-called Mammillaria, but the tubercles are really borne on ribs, while the flowers are 
borne near the center of the plant and originate just above the spines; therefore, this genus 
belongs to the Echinocactanae rather than to the Coryphanthanae; the seeds are unlike those 
of Coryphanthanae. 
We recognize one species. 
The generic name is from 7re5 iov a plain, and ko.ktos cactus, referring to the general 
habitat of the plant. 
1. Pediocactus simpsonii (Engelmann) Britton and Rose in Britton and Brown, Illustr. FI. ed. 2. 2: 
570 . 1913- 
Echinocactus simpsonii Engelmann, Trans. St. Louis Acad. 2: 197. 1863. 
Echinocactus simpsonii minor Engelmann, Trans. St. Louis Acad. 2: 197. 1863. 
Mammillaria simpsonii Jones, Zoe 3: 302. 1893. 
Mammillaria purpusii Schumann, Monatsschr. Kakteenk. 4: 163. 1894. 
Echinocactus simpsonii robustior Coulter, Contr. U. S. Nat. Herb. 3: 377. 1896. 
Plants depressed, globular, up to 15 cm. broad by 12 cm. high, strongly tuberculate; the tubercles 
contiguous; radial spines 15 to 20, spreading, white, acicular; central spines usually 5 to 7, more or 
less spreading, stouter and longer than the radials, 1 to 3 cm. long, the base white but the upper part 
reddish brown or brown throughout; flower-buds obtuse; flowers massed in the center and surrounded 
by brown or whitish wool; outer perianth-segments oblong, obtuse, their margins scarious and ser¬ 
rulate; inner perianth-segments linear-oblong, acutish; filaments golden yellow; style and stigma- 
lobes yellowish. 
Type locality: Butte Valley in the Utah desert and Kobe Valley, farther west. 
Distribution: Kansas to New Mexico, north to Nevada, Washington, Idaho, and 
Montana. 
These plants often take on very weird shapes, very unlike the normal form, and then 
are called the snake cactus or brain cactus. We have photographs of some of these abnor¬ 
mal plants taken by Mr. M. E. Jones in Utah and Nevada. 
