CACTACEJ3. 
43 
infra fuscis ; bacca obovata subclavata seminibus irregularibus acute undulateque marginatis. 
Joints 3-4^ inches in diameter, pulvilli 9-12 lines apart, spines 12-18, smaller ones 4-6 lines 
long, on some plants entirely wanting. Fruit 1^ inches long, much contracted at base, with a 
much depressed, almost funnel-shaped, umbilicus. Seeds cannot be distinguished from those of 
the plant of the plains. 
b. 0. stenochila : prostrata articulis obovatis, pulvillis remotis stramineo-setosis superioribus 
solum armatis ; aculeis singulis albldis patulis, 1-2 minoribus deflexis seepe adjectis ; bacca 
obovata clavata pulposa, umbilico lato parum immerso, seminibus regularibus crassis ansruste 
obtuseque marginatis. (Plate XII, fig. 4-6.) 
At the canon of Zuiii. Joints 4 inches long and 3 wide, flaccid or often lying flat on the 
ground, (in November ;) pulvilli 12 lines apart, small, with yellowish or greenish bristles ; 
larger spines 1-1J inches long, smaller ones less than half as long ; fruit green or pale red, 
very juicy ; 1| inches long, but sometimes much enlarged, even more juicy, and 2-2|- inches 
long and 1 inch in diameter above, long clavate towards the base. Seeds quite characteristic, 
about 2| lines in diameter, 1^ line thick, regular, with a very narrow and somewhat obtuse 
rim, whence the name. 
In the same neighborhood another plant was found with similar seed, but smaller, more 
rounded, and somewhat more spinous joints, fruit less clavate, smaller, seeds similar, but a 
little smaller. 
2. Radice tuberosa. 
c. 0. fusiformis : diffusa s. adscendens, radicibus fusiformibus elongatis, irregulariter incras- 
satis; articulis suborbiculatis majusculis, foliis elongatis subulatis patulis pulvillis subremotis 
griseo villosis, setas elongatas virescente-fuscas gerentibus, plerisque s. solum superioribus 
armatis ; aculeis 2-3 gracilibus inaequalibus deflexis s. patulis, albidis ; floris minoris flavi (basi 
rubelli ?) ovario pulvillis 25 stipato, stigmatibus 8, bacca ovata basi vix clavata demum nudata, 
pulposa rubella, umbilico immerso subinfundibuliformi; seminibus subregularibus crassis 
majusculis acute marginatis. (Plate XII, fig. 7-8.) 
Cross-timbers longitude 97°-99° ; west of the region inhabited by 0. Bafinesquii , and east of 
that of 0. cymochila; also collected by Dr. Wislizenus in the same longitude, but farther north 
on Cow creek and the Little Arkansas, (on the road from Independence to Santa Fe,) and by 
Dr. Hayden, of the United States army, on the Missouri, below the Big Bend. FI. in May. 
Roots form elongated tubers, attenuated at one or both ends |-1 inch in diameter ; joints 4 or 
even 5 inches in length ; leaves 2^-3| lines long, pulvilli 9-12 lines apart, with numerous stout 
yellowish-brown bristles, often 2 lines long, spines 1 or 2, 1-1J- inches long, with a smaller one 
of half the length, more slender than in most other allied forms. Flowers 2-2^ inches in 
diameter, yellow apparently with red base, smaller and with fewer sepals than 0. Bafinesquii , 
but the same mumber of stigmata. Fruit 1^ inches long, umbilicus \ inch wide ; seed rather 
larger and thicker than in 0. Bafinesquii, 2f lines in diameter and 1^ thick. The description 
of the flower is from the specimens collected by Dr. Wislizenus. 
0. macrorhiza, Engl., of Texas, also belongs here as another tuberous rooted form in the 
wide circle of 0. Bafinesquii. 
11. 0. basilaris (sp. nov.) : humilis, articulis obovatis s. subtriangularibus glaucescentibus 
pubescentibus adscendentibus e basi proliferis, fere rosulatis ; foliis subulatis minutis erectis 
rubellis tomentum axillare vix superantibus ; pulvillis subconfertis fulvo-tomentosis setas 
gracillimas demum numerosissimas breves fulvidas et subinde aculeolos setiformes caducos 
gerentibus; floris purpureis ovario obovato pubescente pulvillis plurimis (40-60) confertis fulvo- 
tomentosis instructo, sepalis 20-25 exterioribus oblanceolatis acuminatis, interioribus late obovatis 
cuspidatis, petalis sub-10 obovato-orbiculatis retusis s. obcordatis srepe tenuiter mucronatis, 
