248 CACTACE/E. OpuHtki. 



§ 1. Joints compressed : rhaphe forming a pi'ominent hony margin around the seed : 

 embri/u com/detiug a little more than one circle around the scanty albumen ; 

 cotyledons contrary to the sides of the seed.—- I'latoI'UNTIA. 



« /''riiit pul/iy. 



1. O. Engelmanni, Siilm. lUisliy, cma-sintMuliiig, much bmiicliud : dhovalo 

 joints h to 1 i'odt long, .spui'suly iirnicd with hundlcrf of 1 to 3 or sometimes even f) 

 spines, llie stouter ones jingled, yellow, sometimes with a red-brown base; old trunks 

 losing their spines : llowei-s yellow, about 3 inches wide : petals broailly obovate, 

 truncate : the i)urplo oval juicy berry allout 2 inches long, with a large Hat um- 

 bilicus, and witli 20 to 2;') i)rown-woolly and slightly bristly areolic. — Salm. Cact. 

 cult. 1840, 2;<r) ; Kng( 111). C;aet. Mex. Bound. 47, t. 75, lig. 1 - 4. 



Var. /3. occidentalis, Engelm. Spines fewer, stouter, farther apart : seeds 

 larger. — 0. orucU'iitnlis, Kngelm. & liig. in Cact. of Pacif. Iv. Pep. iv. 38, t. 7. 



Var. (Oy- littoralis, lOngelm. Joints often larger, 1 to 1 ^ feet long: bunchi'S 

 of longer and more slender .s])ines closer togtdlier : fruit similar, but with 40 to 50 

 areoluj : seeds smaller. 



Apparently a polynior})hous species, extending from Southern Texas to the i'lic'ltic, wliiili will 

 jirobably be ulentilied with .some older Mexican species when these jjlants come to be better 

 uuilerstood. The two i'orms of (California are eaaily distinguished by the charueteis given above;. 

 The var. occidadalis has been found on the western slojie of the ino\intains oast of bos Angeles 

 anil south wanl to San Isabel, etc., at an elevation of 1,(»0() to 2,000 feet, rarnj, Sc/iol/. 'i'hi! 

 areolte of the joints are H to 2 inches apart ; spines ^ to 1| inches long ; flowers 3 to 3^ inches 

 wide, yellow with orange centre; fiuit often 1^ inches thick ; seeds 2^ to 2| lines wide. The 

 second form, var. litloralis, extends on the coast from Santa Barbara and the islands in its gulf 

 (0. TUlmann) to San Diego, and southward, O. N. Hitchcock. Seeds 2 to 2J lines in diameter. 



— The limits of tlu:se sjiecics arc dillicult to circumscribe, e8i)nciaily 'because comiilete sjieci- 

 mens are so hard to preserve and extensive observations in the Held have not yet been nuule. Of 

 the three following no more; is known now than there was twenty years ago. 



2. O. chlorotica, luigelm. tt Jiig. Erect, bushy ; old trunks covered with 

 largo areoliu which, retaining tluiir vitality, constantly produce new spines ; joints 

 large, pale green, orbicuiar-obovate, with close-set areoliie, each bearing 1 to f) slemh;r 

 dellexed yellow spines : llowers yellow, 2i to 3 inches wide, with spatulate petals. 



— Cact. of Pacif. P. Pep. iv. 38, t. G, lig. 1 - 3. 



From Mohave Oieek eastward to Bill Williams Mountain in Arizona {Bifjelow) ; 4, 5, or even 7 

 feet high, reatlily recognized by the very spiny trunk and very pale broad joints j to 1 foot long. 



3. O. angustata, luigelm. & Big. Prostrate or ascending, with obovate elon- 

 gated joints : large oblong areohe sparse, bearing brown bristles aiul few (1 to 3) 

 deflexed spines : fruit rather small, deeply umbilicate, with few large seeds. — Cact. 

 1. c. 39, t. 7, fig. 3, 4. 



From Cajon Pass eastward into Arizona, Biyclow. Joints 10 inches long or more, not half iis 

 wide above, nanowed downward ; berry 1^ inches long, uariow ; seeds 3 lines wide. 



4. O. Mohavensis, Engelm. & Big. Prostrate, with large nearly orbicular 

 joints, and more numerous (2 to 6) stout and long often curved brown spines. — 

 Cact. 1. c. 40, t. 9, lig. G - 8. 



On Mohavo Creek, Biijdow. A doubtful form, of which flowers and fruit are unknown. It 

 .seems to apitroach (). phmcantha of New Mexico, and |icriiaps even the stouter western forms 

 of 0. liajiiic.s(iuii. It is indiiNileil iient merely for the attention of future explorers. 



0. Tuna ami 0. Ku!Uh-1ni)I(!A, Mill., are probahly both naturalized alniut the old missioiis ; 

 one with stout yellow spines and insipid fruit, the last with weaker whitish spines, fruit delicious. 



* * Fruit dry. 



-»— Joints and fruit spiny. 



5. O. rutila, Nutt. Prostrate, Avith thick obovate or elongated joints : areole 

 close, armed with numerous slender reddi.sli or gray flexible spines : large flowers 

 purple : stigmas green : berry deeply umbilicate, with large flat broadly margined 



