CACTACE®. 53 
Subgen. 3. CyLmypRopuntra. 
Articuli teretes, clavati seu cylindrici. Aculei plerumque vaginati. 
Flores parvi seu majores. Petala obovata seu orbiculata, rubra seu purpurea, rarius flava, 
Stigmata 5-8, obtusa. 
Bacca umbilicata, sicca seu subsicca, rarissime pulposa; inermis, seu setosa, seu aculeata; floris 
rudimentis dejectis seu persistentibus. 
Semina sutura commissurali cincta, plerumque immarginata, 
Embryo circa albumen copiosius subcircularis. Cotyledones contrari, incumbentes, haud 
raro oblique, interdum parallele, accumbentes. 
The species forming this subgenus have an appearance so striking, and at the same time so 
~ distinct from the common type of Opuntic, that a generic separation has been attempted ; but 
the flowers are so entirely identical, and in the fruit so Jittle difference is observed, that it had 
to be abandoned ; the only real distinction, and a permanent one, as far as my observation goes, 
I find in the embryo; in Cylindropuntia it is less curved, not completing an entire circle, and 
surrounds a moré copious albumen; in Platopuntia, on the contrary, it is somewhat spirally 
coiled, and the space for the albumen is thereby much smaller. It is worthy of remark, that in 
Cylindropuntia the direction of the cotyledons is by far less constant than in other Cactacee ; 
though usually incumbent, as in all other Opuntice, they are very often oblique, and not rarely 
accumbent, like to those of Echinocactus; in O. echinocarpa I have found them invariably so. 
§. 1. Clavate. 
Stems prostrate ; joints short and clavate, tuberculate, proliferous near the base ; the ligneous 
tissue loosely reticulated much like that of Platopuntia; spines more or less compressed and 
striate, the epidermis not or but slightly separating from them; flowers yellow and rather 
large ; fruit always dry, crowned by the persistent remains of the flower, beset on the pulvilli 
with numberless spiny bristles. 
12. O. Parryt, E, in Sill. Journ. Dr. Parry observed this species on the eastern slope of 
the Californian Mountains near San Felipe, and sent notes about it, an extract of which I pub- 
lished in Silliman’s Journal. Since then Dr. Bigelow has collected it 80 or 100 miles northeast 
of that place, near the Mojave river, and in his report a full account of the plant is given. Dr. 
Parry describes the joints as 4-8 inches long, ascending, with white spines only 6 lines long; 
flowers greenish yellow, 1} inch in diameter; stigmata green. 
13.. O. Emoryt, (sp. nov.): prostrata ; articulis cylindricis basi clavatis glaucis adscendenti- 
bus : tuberculis elongatis ; pulvillis magnis setas paucas rigidas gerentibus; aculeis plurimis 
rufis seu fuscis demum cinerascentibus ; interioribus 5-9 validioribus triangulatis subcompres- 
sis porrectis seu deflexis, superioribus solum suberectis ; aculeis exterioribus 10-20 seepe pluri- 
serialibus undique radiantibus, superioribus gracilioribus teretiusculis, inferioribus rigidioribus 
compressis ; floribus flavis extus rubellis; bacca ovata basi clavata flava pulvillis 35-50 stipata 
setosissimis, omnibus seu solum inferioribus aculeatis; seminibus numerosissimis valde ine- 
qualibus plerumque transversis indistincte commissuratis. (Tab. LXX—LXXI.) 
Arid soil south and west of El Paso, especially between the Sand hills and Lake Santa Maria, 
Wright, Bigelow, in Sonora, Wright, and on the lower Gila and in the Colorado desert, 
Schott: fl. August and September.—This is the largest and stoutest of our clavate Opuntice, 
7. 
