1146 



OPUNTIA 



A. Articulations or joints strik- 



inqti) different, flat to cy- 

 lindrical 



AA. Arliciilations or joints .s/w- 

 iliir, more or less flut- 

 tened. 



B. Species from S. America . . . 



BB. Species from N. Amer 

 c. Joints pubescent 



00. Joints not pubescent (except 

 sometimes in O. pycna- 

 cantha). 



D. Fruit fleshy or succulent. 



E. Size of joints large: plants 



mostly large [O. crassa 

 moderately STnadl). 



F. Color of spines white 9. 



1. BrasiliensiB 



, Galapageia 

 . monacantha 

 . aurantiaca 

 . crinifera 



microdasfs 



basilaris 



puberula 



leucotricha 

 triacantha 

 candelabriformis 



FF. Celorofspiiiis if< ll"ir (some- 

 times nil to ichi/,' in O. 

 Ungelmiinnii. j,„ly,iiitha, 

 crassa, and Ficus-Indica.) 



O. Spines none or few 12. 



13. 



GG. Spines always present, few 

 to many. (One form of 

 O. macrocentra has no 

 spines, and occasional 

 plants of O. chlorotica are 

 without spines.) 1 



FFF. Color of spines reddish 

 brown to black, usually 

 with purplish joints 19. 



polyantlia 



Tuna 



chlorotica 



pycnacantha 



Engelmannii 



21. 



22. 

 EE. Sise of joints small: joints 

 variable in shape: plants 

 mostly low or prostrate. 

 (Some forms of O. Safin- 

 esquii have moderately 

 large joints.) '.23. 



24. 



phaeacantha 

 Camanchica 

 macrocentra 

 nigricans 



filipendula 

 Rafinesquii 

 vulgaris 



Frti it dry. 

 spiny 



2(1. Pes-corvi 



31 



ursina 



hystricina 



Missouriensis 



nitila 



arenaria 



fragilis 



AAA. Articulations or joints s 



lar, more or less cylindri- 

 cal. 



B. Species from S. America. 



c. Joints cylindrical, mostly 



elongated 33 cylindrica 



34. vestita 



35. clavarioides 



36. Salmiana 

 00. Joints gluhnse to broadly 



obovate 37. Darwinii 



38. diademata 

 BB. Species from y. America, 

 c. Spines without sheaths: 

 plants mostly small, with 

 clavate joints 30. pulchella 



40. clavata 



41. Grahamii 



42. Schottii 



43. Emory i 



44. invicta 



OPUNTIA 



CO. Spines sheathed: joints cy- 

 lindrical or nearly so, 

 more or less elongated. 



D. Number of spines variable, 



always more than one. 



E. Fruit dry, usually spiny. ..i 



4(i 



it fleshy, proliferous. . . . 50. 

 51 

 (■/ fleshy, rarely prolif- 



1>D. Number of spines few, usu- 

 ally one, rarely more or 

 wanting 59. 



Gl. 



Davisii 

 , acanthocarpa 

 , echinocarpa 

 , Bernardina 

 , serpentina 



proiiiera 



Sulgida 



Bigelovii 



imbricata 



arborescens 



spinosior 



Whipplei 



versicolor 



tetracantha 



arbuscula 

 leptocaulis 

 ramosissima 



1. Brasili^nsis, Haw. A large, tree-like plant reach- 

 ing a height of 1.5-lS ft., numerously branched, with a. 

 thick, roundish crown and an upright trunk, 4-6 in. in 

 diani., and bearing numerous spines 1 in. or less in 

 length: joints of two kinds, cylindrical, unarticulate, 

 elongate ones and others which are shorter and much 

 flattened and which arise as offshoots from the former; 

 the latter leaf-like, thin, 2-6 in. long, oblong, rarely ob- 

 long-lanceolate or orbicular, dark green, margin angu- 

 lar, sometimes irregular: areolae with short, gray wool 

 ami numerous brown bristles; spines usually 1, some- 

 times 1-3 small additional ones, l-2}4 in. long, mostly 

 friim till' iiiMrKiiiMl areoliB, white, with brownish tips: 

 Ms nunii'r<ins, citron-yellow, 2 in. wide: fr. globose or 

 ellipsoidal, yellow, about 1^ in. in diam. Brazil and 

 southward. — One of the species most frequent in cult. 



2. Galapageia, Hemsl. An upright, tree-like plant 

 6-10 ft. high, with a circular, spreading crown and a 

 very spiny trunk, 6-8 in. in diam., and light-colored 

 bark becoming loosened and hanging in fragments 

 from the older stems: joints elliptical to oblong, thick, 

 10-14 in. long: spines at first 3-4, spreading, flexible, 

 increasing in number and size with age, finally covei- 

 ing the joints with long, brush-like bundles: fls. sma'l, 

 less than 1 in. wide, red: fr. subglobose, red. Galapa- 

 gos Islands. 



3. monacfintha, Haw. An upright plant branching 

 from the ground and reaching a height of 6 or more 

 feet: joints oblong to elliptical, rather thick, terminal 

 ones much thinner, 5-12 in. long, .3-6 in. wide, bright 

 green: areolas with uniformly short wool and yellowish 

 brown bristles; spines 1-2, seldom more, erect, M-IH 

 in. long, yillow fu dark reddish brown: fls. yellow, 3 

 in. wide: fr. ellipsoidal to pyriform, occasionally pro- 

 liferous, red, somewhat spiny. Argentine Republic. 

 — The horticultural variety varieg^ta is in the trade. 



4. aurantiaca, Gill. A numerously branched, rather 

 weak, semi-prostrate plant 3-5 ft. high: joints linear- 

 lanceolate to lanceolate, 2-10 in. long, ^j-1 in. wide, ellip- 

 tical in transverse section, dark green, turgitl : areolm 

 with a tuft of grayish white wool and bright yellow 

 bristles ; spines 4-6, spreading, straight, stiff, brown 

 to yellow, the longest less than 1 in. in length: fls. yel- 

 low, 1/^-2 in. wide: fr. carmine-red, globose, with short 

 spines; seed with woolly hairs. Argentine Republic. 



5. crinifera. Pfeiflf. (O. senilis, Parm.). A much- 

 branched, wide-spreading plant, about 3 ft. high: joints 

 obovate to elliptical, 6 in. long and 3-4 in. wide, dark 

 green, occasionally glossy: areolae crowded, small, with 

 white wool, numerous golden yellow bristles, and a 

 variable number of long silky hairs: spines 6-8. later 

 more, white, glistening, reaching 1 in. in length, the 

 long silky liairs particularly developed on the under 

 side of the young joints : fls. 3K-4 in. wide, golden 

 yellow, often reddish. Brazil(?). 



