SELENICEREUS. 

 KEY TO SPECIES. 



Areoles of the ovary and flowei-tube bearing long hairs. 

 Branches ribbed, angled or subterete, not spurred. 



Areoles of the branches borne on the ribs or angles. 

 Spines of the branch-areoles acicular. 



Hairs of flower-areoles tawny or whitish i . 



Hairs of flower-areoles bright white. 



Branches 4 or 5-angled; stem-areoles without bristly hairs. 



Spines brown 2 . 



Young spines yellow 3. 



Branches 7 to lo-ribbed; stem-areoles with many bristly hairs 4. 



Spines of the branch-areoles short, conic. 



Branches 9 or lo-ribbed; branch-areoles with many appressed hairs 5. 



Branches 4 to 6-ribbed; young branch-areoles with few long hairs. 



Stems stout, 3 to 5 cm. thick 6. 



Stems slender, 1.5 to 3 cm. thick. 

 Hairs of flower-areoles white. 



Ribs not tubercled 7. 



Ribs tubercled 



Hairs of flower-areoles brown 9. 



Areoles of the branches borne on prominent knobs 10. 



Branches with a stout, deflexed spur under each areole 1 1. 



Areoles of flower-tube and ovary without long hairs. 

 Areoles of the branches spiniferous. 



Spines of the branch-areoles acicular 12. 



Spines of the branch-areoles short, conic. 



Ribs 7 or 8, obtuse; spines from the areoles on the ovary i to 3 13. 



Ribs 4 to 6, acute; spines from the areoles on the ovary 10 or more 14. 



Areoles of the branches unarmed. 



Ribs prominent, 3 to 5; flowers white 15. 



Ribs low, 6 to 12; flowers red 1 6. 



197 



5. grandiflorus 



S. urbanianus 

 S. coniflorus 

 S. hondiirensis 



S. donkclaarii 

 S. pleranlhus 



S. kunthianus 

 S. brcvispinus 

 S. boeckmannii 

 S. macdonaldiae 

 S. hamatits 



S. uagans 



S. murrillii 

 S. spinulosus 



S. inermis 

 S. wercklei 



1. Selenicereus grandiflorus (Linnaeus) Britton and Rose, Contr. U. S. Nat. Herb. 12: 430. 1909. 



Cactus grandiflorus Linnaeus, Sp. PI. 467. 1753. 



Cereus grandiflorus Miller, Gard. Diet. ed. 8. No. n. 1768. 



Cereus grandiflorus affinis Salm-Dyck, Cact. Hort. Dyck. 1849. 51, 216. 1850. 



Stems clambering, often 2.5 cm. in diameter, green or bluish green; ribs usually 7 or 8, some- 

 times fewer, low, separated by broad, rounded intervals; spines acicular, various, i cm. long or less, 

 yellowish brown or brownish, in age gray, intermixed with the numerous whitish hairs; flower-buds 

 covered with tawny hairs; flowers about 18 cm. long; outer perianth-segments narrow, salmon- 

 colored; inner perianth-segments white, acute, entire; style often longer than the inner perianth- 

 segments; fruit ovoid, 8 cm. long. 



Type locality: Jamaica. 



Distribution: Jamaica and Cuba. Widely planted and escaped from cultivation in 

 tropical America. 



We have observed seeds germinating within the fruit of this species. 



S. grandiflorus and perhaps some of its allies are used medicinally as a heart tonic. In 

 the trade the plant is sometimes called Cactus mexicanus. 



Cereus scandens minor Boerhaave (Arendt, Monatsschr. Kakteenk. i: 82. 1891) prob- 

 ably refers to this species, as does also C. grandiflorus var. minor Salm-Dyck and var. 

 spectabilis Karwinsky (Forster, Handb. Cact. 415. 1846). C. grandiflorus uranos Ricco- 

 bono (Boll. R. Ort. Bot. Palermo 8: 249. 1909), doubtless the same as Cereus uranos Hortus, 

 is said to be but a form of this species. The C. uranus nycticalus mentioned (Monatsschr. 

 Kakteenk. 3: 117. 1893) is a hybrid and is like C. grandiflorus callicanthits Riimpler (Forster, 

 Handb. Cact. ed. 2. 750. 1885; Cereus callicanthus Monatsschr. Kakteenk. 3: 109. 1893). 

 Cereus grandiflorus viridiflorus (Monatsschr. Kakteenk. 6: 80. 1896) is a garden hybrid. 

 The varieties haiticnsis and ophites (Monatsschr. Kakteenk. 13: 183. 1903) may belong to 

 related species rather than to Selenicereus grandiflorus. This is probably true of the varie- 

 ties grusonianus and mexicanus \isted in Haage and Schmidt Catalogues. Cereus maximiliani, 

 C. grandiflorus maximiliani, and C. nycticalus maximiliani are doubtless hybrids with one of 

 the common cultivated species, perhaps 5. grandiflorus, as believed by Berger. Cereus 

 schmidtii (Monatsschr. Kakteenk. 4: 189. 1894) may be Cereus grandiflorus schmidtii 



