Engelmann, George Feb. 6, [1845] [5] (seq. 139)

6.
sparsim repando-denticulatis, adpresse pubescentibus, floribus in spicis laxis
ramosis sessilibus; bracteis linearibus deciduis; calycis segmentis tubum plerumque
superantibus, ovario canescente multo longioribus; petalis spathulatis longe uniquiculatis
calyce et staminibus brevioribus; nuce sessili, ovata, subacuta, 4 carinata, nervis 4
inconspicuis intermediis notata.

Prairies at the margin of woods between Brazos & Colorado, also west of Houston;
fl. August & September. — 6 to 9 feet high, often exclusively covering large spaces
of ground. Near Gaura biennis but taller, more branching, leaves narrower
flowers much smaller, petals spathulate and fruit shorter and thicker. —
240 Gaura drummondii Torr & Gr. Naked soil, roadsides in prairies, ravines
or
abrupt steep banks of rivulets, west of the Brazos; May. — Stem and leaves
canescently
hairy; leaves in our specimens mostly undulate and sinuate-dentate; calyx-tube
as long as the ovary segments mostly much longer; petals deep red in the dry
specimens.
The very peculiar shape of the fruit is well descrbed by Torrey & Gray in Flora.
241. Gaura parviflora Dougl On deserted anthills in the sandy prairies
between Brazos
& Colorado. July & August. — The ovaries as well as the fruits in all our specimens
are not glabrous, but canescently pubescent, and the fruits acutish.
243 Jussiaea occidentalis Nutt along margins of rivulets, where they are not
shaded
between the Brazos & Colorado. July. — Petals obcordate.
242 Stenosiphon virgatus Spach "high prairies on the Colorado, often on
rocky soil sparsely,
244. Opuntia frutescens n.sp. Caule erecto ramoso, teneti, ligneo, cenereo, duplicites
aculeato; ramis junioribus articulatis, fragilibus, subcylindricis, angulatis,
brevioribus, viridibus, flores in aculeoorum fasciculis lateralites s. sub apicem
gerentibus; fructibus obovatis, carnosis (scarlatinis) fasciculis aculeorum
piliformium obsitis; semina pauca (alba) compressa, reniformia includendibus,
persistentibus, proliferis.

This remarkable Cactus was collected as stated above near the Muskit-thickets
(No. 233) on the Colorado, in August; it acquires a hight of from 3 to 5 feet, has
a branching ligneous stem, covered with a light gray bark and sometimes even with
lichens. It bears bunches of small hairlike spines, with one larger one (4-6 lines
long) which disappear on the oldest stems. The wood is close grained and very hard.
The younger branch are green and angular and bear the last, short (about
1 inch long) articulations, which very easily break off; these bear when young,
as the other Opuntia — short terete subulate leaves, and in the axillis of these
one
larger spine and above this a bunch of smaller ones. — Our specimens are
not in flower, but are covered with the obovate umbulicate scarlet fruits,
about 8 lines long, which are fleshy but not juicy and contain very few (2 to 5)
white compressed seeds. — A most remarkable circumstance is that the
fruits frequently bear one or more (even 4 or 5) new branches at the upper
bunches of spines; they either fall off with these branches, or become persistent
dry up and finally form part of the stem.

This species is apparently near Opuntia fragilis Nutt but is distinguished
by the high ligneous stem, the mostly lateral position of the flowers and
the fleshy, proliferous fruit.

Besides this Mr Lindheimer has sent us 7 other Cactaceae, most of them
in living specimens.

7)
Opuntia without fruit or flower, probably O. vulgaris Mill, several
feet high
with large obovate joints and few spines, from the Brazos.
Opuntia, perhaps O. missouriensis DC low, with smaller orbicular
joints, with
numerous large straight brown spines and bunches of also brown prickles, which
are larger than in the other species; flowers yellow, in May. On sterile
prairies, 12 miles west of Houston.
Mammillaria similis n.sp. caespitosa, axillis glabris, tuberculis ovatis apice
spiniferis
tomento circudatis; floribus sparsis, baccis globosis scarlatinis.

On sandstone rocks near Industry, west of the Brazos. — Evidentally very
near M. simplex, but caespitose, forming tufts of 6 to 12 inches diameter; tubercu-
les with about 12 white (not red) radiating spines, flowers not seen; berries
scarlet of the size of a large pea, rather dry, with numerous black subglobose
scrobiculate seeds with and elongated white hilum.
Mammillaria subcata n.sp. caespitosa, tuberulis ovais erioribus sulco prolifero superne
notatis, apice spiniferis, spinis rectis radiantibus, cinereis, in plantis
senioribus spina centrali subrecurva majore; floribus centralibus,
fasciculatis; fructibus oblongis, floris rudimentis coronatis, virescentibus,
polyspermis.

With the foregoing; but a and similar to it, but a much larger plant!
I would take it without hesitation for M. vivipara Haw it that was not
described every where as having bearded tubercules! Ours are very
spiny; in the young specimens we find 8 to 10 radiating horizontal
about equal spines; in the older ones one becomes central, much stouter
often 8 lines long, erect or rather curved somewhat backwards. Flowers
not seen. Fruits sessile in a cluster in the centre of the plant, surrounded
and half hidden by the innermost tubercule, enclosed at the base by a tomentum,
about 10 to 12
lines long, oblong, juicy, greenish; full of black, smooth shining
seeds, which are compressed on one side toward the hilum.

Echinocactus setispinus n.sp. subglobosus, apice retusus, costis plerumque
13
ac[loss] obliquis, aculeis (15-18) fasciculatis, tenuibus, flexuosis e flavicante
fasc[loss] 10-12 inferioribus brevioribus radiantibus, 3 superioribus elongatis;
1-3 [loss]-libus longissimis, erectis; floribus minutis supra fascicularum
fa acu[loss]m fasciculos ortis, basi tomento cinctis; sepalis in tubum
concretis, spicibus liberis scariosis, late ovatis, acuminatis, margine
fimbriatis; fructibus? seminibus ovatis, nigris opacis, minutum
tuberculatis.

Common among the Muskit-trees on the Colorado River. — Near Echinocactus
tenuispinus Link & Otto, from Brasilia, but distinguished by the somewhat
oblique
and acute, not straight, obtuse ribs, which show at their bases a transition
to the tubercular structure of the Mammillariae; also by the very small flowers.
Our specimens are about 2 inches in diameter and 1 1/2 inch high, have 13
(one of them 15) pretty sharp ribs, separated by deep grooves. The spines near the
base
are shorter, mostly broken off, towards the top they are longer, and flexible; those in
the centre of the bunches are longest, (about 15 lines long). We find a few
shrivelled up flowers and one incomplete fruit on our specimens. They do not
orginate from the clusters of spines, but from an impression in the rib above them.
The flowers are about 5 lines long, at base surrounded by a tomentum; the seeds
are punciculate, black, not shining.