222 THE CACTACEAE. 
KEY TO SPECIES. 
A. Radial spines acicular, appressed, very unlike the central ones; species of Curacao, 
Aruba, and Bonaire........... 0.0 e eee e cere eee eee etree 1. C. macracanthus 
AA. Radial spines subulate, spreading, or diverging. ; 
B. Flowers 3 to 4.cm. long; fruit 5 to 6 cm. long; species of Jamaica............... 2. C. melocactus 
BB. Flowers 2.5 cm. long or less; fruit 1 to 2 cm. long. — 
C. Spines all very stout; species of Hispaniola... .......-. ++. - +5555 e seers 3. C. lematret 
CC. Spines relatively slender. ; ; 
D. Spines flexible, greatly elongated; species of Brazil............-.--++-++-- 4. C. oreas 
DD. Spines stiff, not greatly elongated. 
EK. Central American and Mexican species. . 
Spines up to 3 cm. long..........6. 000 c eee ee eet eee . 5. C. ruestit 
Spines shorter. . 
Central spines about as long as the radial ones..............---.-+-- 6. C. maxonit 
Central spines twice as long as the radials or longer...............--- 7. C. salvador 
EE. West Indian species. ; oe 
Radial spines very slender, widely spreading, slightly curved........... 8. C. broadwayt 
Radial spines stouter, divergent, straight or nearly so. ; 
Ribs thick; plants up to 4 dm. in diameter................5...5--55- 9. C. intortus 
Ribs thinner; plants 1 to 1.5 dm. in diameter............-.-...-.55. 10. C. harlowit 
EEE. South American species. 
Spines white, at least when young. 
Spines curved; species of Colombia. 
Flowers 1 cm, wide or less..........0.0 000 eee ce eee 11. C. amoenus 
Flowers 2.5 cm. Wide.........0 0.2 cece ete eee eens 12. C. obtusipetalus 
Spines straight; species of Venezuela and Patos Island, Trinidad...... 13. C. caestus 
Spines gray, brown or reddish. . 
Spines dark brown; species of Peru............. 2.000. 0ee cee eee eee ee 14. C. townsendit 
Spines gray to reddish; species of Brazil. oo, 
Spines straight, up to 3 cm. long................00 050 eee 15. C. bahtensts 
Spines curved, shorter. . 
Berry white or pale pink..............00 00.0.0 cece eee 16. C. melocactotdes 
Berry red to carmine. . 
Spines very stiff, curved backward.......................05. 17. C. zehntnert 
Spines slender, curved upward...............0 0000 cece ee eee 18. C. neryt 
1. Cactus macracanthus* Salm-Dyck, Observ. Bot. 1:3. 1820. 
Cactus pyramidalis Salm-Dyck, Observ. Bot. 1: 4. 1820. 
Melocactus macracanthus Link and Otto, Verh. Ver. Beférd. Gartenb. 3: 418. 1827. 
Melocactus pyramidalis Link and Otto, Verh. Ver. Beférd. Gartenb. 3: 419. 1827. 
Echinocactus salmianus Link and Otto, Verh. Ver. Beférd. Gartenb. 3: 423. 1827. 
Melocactus salmianus Link and Otto, Verh. Ver. Beférd. Gartenb. 3: pl. 13. 1827. 
Melocactus spatangus Pfeiffer, Enum. Cact. 45. 1837. 
Melocactus lehmanni Miquel, Linnaea 11: 642. 1837. 
Melocactus zuccarintt Miquel, Linnaea 11: 645. 1837. 
Melocactus microcephalus Miquel, Nov. Act. Nat. Cur. 18: Suppl. 1.156. 1841. 
Melocactus pyramidalis carneus Miquel, Nov. Act. Nat. Cur. 18: Suppl. 1. 166. 1841. 
Melocactus parvispinus Suringar, Versl. Med. Akad. Wetensch. III. 2: 183. 1886. Not De Candolle, 1828. 
Melocactus koolwijckianus Suringar, Vers]. Med. Akad. Wetensch. III. 2: 184. 1886. 
Melocactus rubellus Suringar, Versl. Med. Akad. Wetensch. IIT. 2: 184. 1886. 
Melocactus stramineus Suringar, Versl. Med. Akad. Wetensch. III. 2: 185, 186. 1886. 
Melocactus (rubellus) ferox Suringar, Versl. Med. Akad. Wetensch. III. 2: 185. 1886. Not Pfeiffer, 1837. 
Melocactus (rubellus) hexacanthus Suringar, Versl. Med. Akad. Wetensch. III. 2: 185. 1886. 
Melocactus (stramineus ?) trichacanthus Suringar, Vers]. Med. Akad. Wetensch. III. 2: 186. 1886. 
Melocactus reversus Suringar, Versi. Med. Akad. Wetensch. III. 2: 187. 1886. 
Melocactus retiusculus Suringar, Versl. Med. Akad. Wetensch. III. 2: 187. 1886. 
Melocactus angusticostatus Suringar, Versl. Med. Akad. Wetensch. Amst. III. 2: 188. 1886. 
Melocactus retiusculus angusticostatus Suringar, Versl. Med. Akad. Wetensch. III. 2: 188. 1886. 
Melocactus approximatus Suringar, Versl. Med. Akad. Wetensch. III. 2: 189. 1886. 
Melocactus evertszianus Suringar, Vers]. Med. Akad. Wetensch. III. 2: 190. 1886. 
Melocactus patens Suringar, Vers]. Med. Akad. Wetensch. III. 2: 190. 1886. 
Melocactus cornutus Sutingar, Versl. Med. Akad. Wetensch. III. 2: 191. 1886. 
Melocactus intermedius Suringar, Versl. Med. Akad. Wetensch. III. 2: 192. 1886. 
Melocactus pusillus Suringar, Versl. Med. Akad. Wetensch. III. 2: 192. 1886. 
Melocactus spatanginus Suringar, Versl. Med. Akad. Wetensch. III. 2: 193. 1886. 
Melocactus koolwijkianus adustus Suringar, Versl. Med. Akad. Wetensch. III. 6: 438. 1889. 
Melocactus argenteus Suringar, Vers]. Med. Akad. Wetensch. IIT. 6: 439. 1889. 
Melocactus argenteus tenuispinus Suringar, Vers]. Med. Akad. Wetensch. III. 6: 439. 1889. 
Melocactus roseus Suringar, Versl. Med. Akad. Wetensch. III. 6: 439. 1889. 
Melocactus limits Suringar, Versl. Med. Akad. Wetensch. III. 6: 440. 1889. 
Melocactus obliquus Suringar, Versl. Med. Akad. Wetensch. III. 6: 440. 1889. 
Melocactus flexus Suringar, Versl. Med. Akad. Wetensch. III. 6: 441. 1889. 
Melocactus incurvus Suringar, Versl. Med. Akad. Wetensch. III. 6: 441. 1889. 
Melocactus nanus Suringar, Versl. Med. Akad. Wetensch. III. 6: 441. 1889. 
Melocactus rudis Suringar, Versl. Med. Akad. Wetensch. III. 6: 442. 1889. 
*This name was originally spelled Cactus macrocanthos by Salm-Dyck. 
