222 
the cactaceae. 
Key to Species. 
A. Radial spines acicular, appressed, very unlike the central ones; species of Curasao, 
Aruba, and Bonaire. i. 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. 3. C. lemairei 
CC. Spines relatively slender. 
D. Spines flexible, greatly elongated; species of Brazil. 4. C. oreas 
DD. Spines stiff, not greatly elongated. 
E- Central American and Mexican species. 
Spines up to 3 cm. long. 5. C. ruestii 
Spines shorter. 
Central spines about as long as the radial ones... 6. C. maxonii 
Central spines twice as long as the radials or longer. 7. C. Salvador 
EE. West Indian species. 
Radial spines very slender, widely spreading, slightly curved. 8. C. broadwayi 
Radial spines stouter, divergent, straight or nearly so. 
Ribs thick; plants up to 4 dm. in diameter. 9. C. intortus 
Ribs thinner; plants 1 to 1.5 dm. in diameter. 10. C. harlowii 
EEE. South American species. 
Spines white, at least when young. 
Spines curved; species of Colombia. 
Flowers 1 cm. wide or less. n. C. amoenus 
Flowers 2.5 cm. wide. 12. C. obtusipetalus 
Spines straight; species of Venezuela and Patos Island, Trinidad. 13. C. caesius 
Spines gray, brown or reddish. 
Spines dark brown; species of Peru. 14. C. townsendii 
Spines gray to reddish; species of Brazil. 
Spines straight, up to 3 cm. long. 15. C. bahiensis 
Spines curved, shorter. 
Berry white or pale pink. 16. C. melocactoides 
Berry red to carmine. 
Spines very stiff, curved backward. 17. C. zehntneri 
Spines slender, curved upward. 18. C. neryi 
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. Beford. Gartenb. 3: 418. 1827. 
Melocactus pyramidalis Link and Otto, Verh. Ver. Beford. Gartenb. 3: 419. 1827. 
Echinocactus salmianus Link and Otto, Verh. Ver. Beford. Gartenb. 3: 423. 1827. 
Melocactus salmianus Link and Otto, Verh. Ver. Beford. Gartenb. 3: pi. 13. 1827. 
Melocactus spatangus Pfeiffer, Enum. Cact. 45. 1837. 
Melocactus lehmanni Miquel, Linnaea 11: 642. 1837. 
Melocactus zuccarinii Miquel, Linnaea 11: 645. 1837. 
Melocactus microcephalies Miquel, Nov. Act. Nat. Cur. 18: Suppl. 1. 156. 1841. 
Melocactus pyramidalis carneus Miquel, Nov. Act. Nat. Cur. 18: Suppl. 1. 166. 1841. 
Melocactus paroispinus Suringar, Versl. Med. Akad. Wetensch. III. 2: 183. 1886. Not De Candolle, 182S. 
Melocactus koohvijekianus Suringar, Versl. Med. Akad. Wetensch. III. 2: 184. 1886. 
Melocactus rubellus Suringar, Versl. Med. Akad. Wetensch. III. 2: 184. 1886. 
Melocactus stramineus Suringar, Versl. Med. Akad. Wetensch. III. 2: 185, 186. 1S86. 
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, Versl. Med. Akad. Wetensch. III. 2: 186. 1886. 
Melocactus reversus Suringar, Versl. 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 approximate Suringar, Versl. Med. Akad. Wetensch. III. 2: 189. 1886. 
Melocactus evertszianus Suringar, Versl. Med. Akad. Wetensch. III. 2: 190. 1886. 
Melocactus patens Suringar, Versl. Med. Akad. Wetensch. III. 2: 190. 1886. 
Melocactus cornutus Suringar, Versl. Med. Akad. Wetensch. III. 2: 191. 1886. 
Melocactus intermedins 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, Versl. Med. Akad. Wetensch. III. 6: 439. 1889. 
Melocactus argenteus tenuispinus Suringar, Versl. Med. Akad. Wetensch. III. 6: 439. 1889. 
Melocactus roseus Suringar, Versl. Med. Akad. Wetensch. III. 6: 439. 1889. 
Melocactus limis 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. 
