222 



THE CACTACEAE. 



Key to Species. 



A. Radial spines acicular, appressed, very unlike the central ones; species of Curacao, 



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. areas 



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. harlowli 



EEE. South American species. 



Spines white, at least when young. 

 Spines curved; species of Colombia. 



Flowers 1 cm. wide or less 11. C. amoenus 



Flowers 2.5 cm. wide 12. C. obtusipelulus 



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. 1S20. 

 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 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, 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. 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, 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 approximatus 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. 



