OPUNTIA 



in diani., having a thick, grayish, scaly, unarmed barls: 

 joints congested toward the ends of the larger branches, 

 ovate to ovate-cylindrical, 2-8 in. long and often 2 in. 

 thick, very fragile and tumid, easily becoming detached 

 and taking root, bluish green, somewhat glaucous : areo- 

 IfB with white wool and bright straw-colored bristles; 

 spines on young growth 5-8, increasing yearly until 

 ultimately 30-50, finally deciduous, with loose, glisten- 

 ing, white or straw-colored sheaths 1% in. or less long: 

 tls. %-l in. wide, pink : fr. obovate to globose, light 

 green, pendulous, in large, proliferous clusters, sorae- 

 titnes .")0 in a single cluster. Southwestern U. S. and 

 Ndith Mexico. -The common "Cholla" of the Arizona 

 plains, where it often becomes a fair sized tree and nota- 

 ble for its formidable armor of barbed spines completely 

 hiding the surface of the plant. 



Var. mamillElta, Coult. Differs in having fewer, 

 shorter spines. 



'>2 Bigelovii, Engelra. An erect, compact plant, 4-6 ft. 

 lii.h 1 11. h liu'hn, with fragile woody skeleton which 

 li .1 - 11 t ipi . 11 ill loints of the first year's growth, the 

 iiio^t li. ii~. I\ -.]iiiie covered and difficult to handle of 

 tin \]ii In li ( t] utiti'is Tomts readily detached and 

 t Mill n- t 111 I il U liiirs n\ate, short elliptical to long 

 nil ihi 111 il \Mih 1 lunded ends, readily breaking 

 ti 11 III ] I ml 111.1 t ikiii_' mot, pale green, fragile, tu- 

 nii.l I ill 11 il II. ■~ tmiuintly 3-5 m. long and half as 

 till k 11 I I I -. together, with white wool and pale 

 \.ll \ 111 11 - ^ [lines 10-20, some very small, mcreas- 



II _' 111 1 mill 1 I- stems become older, straw colored, 

 1.1 -. -Il .th. .1 1 in. or less long, completely hiding the 

 suit,iee ot th( plant: fls. greenish red, ] in. broad: fr. 

 very spm\ . ovate. l^^-'Z in. long and one third as wide, 

 few" seeded, mostly sterile. Ariz., Calif. 



53 imbricita, P. DC. A wide spreading, irregularly 



III 111. liiii_ -hull, lauh ni..ii ili in " ft liu'h. the trunk 

 an. I In.. 1 liii.h -with.liik 1 luh 111. uiued bark: 

 1 .lilt- Il [II. iitl\ IJ . 1 11 111 1 11. 11 1 I P4 m. thick, 

 witli\.i\ |.i. iiiiii. jit 1..11.- .11-1,1. till 1 l.s- areolae 

 withMlloHish «ool Mu\ stlau Lol.,i..i liii-tl.s spines 

 2-'), of \ ariable length, 1 in. oi 1.-- I..11.' I .. .-« h 

 sheathed, white to straw-colored, tl- J--'^ iri wi.le. 

 lightpurple: fr. unarmed, depressed ml.. I...-. «itlilii.'e 



,,„.. fi..ii, «lii 1 11 .hir 1- 11 11- -.1 illii _i will .liil. 1 

 ent hal.lt 11 1 li I n.. 1 1 mt- I 11.. 1 111. .1. 1 1. 111111. nt 

 tubercles ni.l t.w.i -] 111. - The truit and Hower also 

 show marke.l .liH. n n. t - 



54. arborescens.l ii.'tlni {0 slel!Ata,Sa\m.). Anarbor 

 escent, mini. i-l I 1 m. h. d pi mt 4-h ft hi„'li with 

 trunk of 1 11 I 1 il 1 



tuberrlt- tl\ 



pendulun- 11 1 111 



long and I m 1 1 ... 1 1, .liii, \liitL 



wool and small \.ll i I .1 i i 1 >\\u biistlts, spines 



(j-20, variable m ifii.ili 1 in 1 1 -s, central ones more 



loosely sheathed li iii\ 11 .1 li-h brown, white to 



straw colored sin itl il ) 1 1 1 I. J-1 in wnle tr 



subglobose. 1 111 1 i 



Southwest U S - I 



cata and O. i^pttu 1 11 li I 1 il i w . 



Ditters from the latter in haMiig mm li lai.'ti njoie 

 cristate tubercles, fewer spines and different truit. 



55 spindsior, Toumey. A small tree, 6-12 ft. high, 

 with numerous veitKilIate bran. lies, tmmiiig a rounded 

 head, the cvlmdii I 1 11 I 1 II I 1 lung a few 

 feet abo\e the gi 1 l.iown cu 



gravish unarmed 1 . 1 1 I 1 .. iiilu lou s , 



ultimate ones u-ii ill I 111 thiik. 



short, and riuh < iiiispu u.iush shi ithed usualh ' -■'4 

 in. long: fls. showy, bright to dark purple, 2-2H m. 

 wide, in whorls at tlie ends of the joints: fr. elliptical to 

 oblong, rarely obovate to globose, lH-2Xin- long, yel- 



OPUNTIA 



1151 



low, frequently remaining on the stems during the sec- 

 ond year. Ariz., northern Mex. 



56. Whipple!, Engelm. and Bigel. A spreading, sub- 

 prostrate shrub, rarely exceeding 2 ft. in height, with 

 numerous ascending secondary branches, having short, 

 crowded, proniin.nt tuli.r.l.-,-: ji.int- variable, terminal 

 ones clavate. ■_'-.'. in. k.iiL; nn.l ' -'1 in. thick, mostly 

 armed on up]., r liiill : m . ..l,r \\ ii h -lii.rt white wool and 

 a few short, li(;litH'..l..r. .1 l.ii-il.-; -pines white, very 

 variable, on teniiiiial Joints, usually from 1-3 con- 

 spicuous loose - sheathed interior ones and several 

 small, deflexed or radiating ones: fls. greenish jellow, 

 crowded at the ends of the joints, 1-lMin wide: fr. 

 unarmed or with tew spines, piriform to subglobose, 

 densely tubei. Ill It. \.ll.u m tint..l with s.ailet,H-l 

 m. in diam , lii \ in.' m.i 1 . in unin. ii t 1 I . .1 1 tin plant 

 during the •« int. I ^ iitl « -1 I v n | , iilm.stMex. 



probably trom contusion in the original description. 



57. versicolor, Engelm. A small, numerously branched 

 tree, 6-10 ft. high, with rounded head and a short trunk, 

 having sill. lutli li_rht lini\\iiin 1 eddish brown, unarmed 

 baik 1 111 I 1 I I 1 I I iisuallj 6-12 in. long, sorae- 

 tinn .11 en, more or less colored 

 with Mth short gray wool and 



light I II. s variable, on terminal 



joints, us.i ,U\ 11., ill , 1 . i.u 1 loints \Mtli 10-20. rarely, 

 howi.\er, lucieasiiig iii imiulieis attei the second jear, 

 reddish brown, uith inconsj.icuous close httiiig sheaths, 

 % m. or less long Hs bic.nze loloiid, 1-P, in wide: 

 fr. pyriform to cla\atp, of same color as joints, never 

 yellow, sometimes tinged with red or puride, unarmed 

 or with a few persistent short spines, 1-2 m. long. 

 Ariz., northern Mex. 



58. tetracttntha, Toumey. An irregularly branching 

 shrub, 2-5 ft. high, primary blanches from a stout, up- 

 right trunk 2-4 m. in diani , and bearing numerous 

 short lateral ones at irregular intervals : joints very 

 variable in length, usualh 4-111 in long and K in. thick: 

 areolae with whiti-li w. .1 m I 1 1. - . nt shaped tuft of 



1% in. long, -t 'ur I l\ 1 itl .1 straw-colored, 



flittpned, sti. 11 1\ .1. Il I I 1 i-mg in numbers 



.•n 1.1(1. r limits II- . 1 in broad: fr. 



. I .\ It. t.. - il .1 I I 1 II. \, scarlet, un- 



1549. Opuntia 



No CI 



height of 5 ft , but always with an upright, well-defined 

 trunk, having rough, brown, unarmed bark, joints usu- 

 ally 2-t in. long and J^ in. wide, easily broken from the 

 plant aieoliP comparatively large, with white wool and 

 brush hk. tiitts . t.l..ng, slender, yellow bristles: spines 

 yell..« iiiilh I ti. .|uently a small, slender, additional 

 one at nil. 1 -I I. . 1-1'. m. long, loosely sheathed: fls. 

 bronzi-.-..l.>ii-.l, ',-1 in. wide: fr. unarmed, of same color 



