. CEREUS. 15 



to 10, acicular, yellowish brown to bright yellow, the longest ones 5 cm. long; flower-buds purplish, 

 erect, 16 cm. long, pointed; scales on ovary and lower part of flower-tube minute, deep red, naked 

 in their axils; flowers white; fruit narrowly oblong, 6 to 7 cm. long, purplish red, when mature 

 splitting on one side exposing the white edible pulp and black seeds; style persisting after the 

 perianth falls; seeds shining, 2 mm. long. 



Type locality: Not cited. 



Distribution: Coast of Brazil and Uruguay. 



This species of the coast of Brazil is what Schumann described as Cereus pitajaya, but 

 an examination of the original description of Cactus pitajaya Jacquin shows that this plant 

 came from the coast of Colombia and is evidently an Acanthocereus. 



Cereus pernambucensis is common along the seacoast of Brazil. Dr. Rose observed it 

 at Bahia, Rio de Janeiro, Cabo Frio, and at Santos, but it is reported from both north and 

 south of those regions. It is very common in the sand just back of the ocean beach, and 

 on rocks near the sea, where it is usually low, often prostrate, growing in clumps. At 

 times it grows much taller, unless we have associated another species with it. The taller 

 plants suggest a small form of C. janmcani, which is normally an interior desert species, 

 while C. pernambucensis is to be found only on the coast; besides the differences in size of 

 flowers and fruits, C. pernambucensis has shining seeds, which in the other species are dull. 



Illustration: Vellozo, Fl. Flum. 5: pi. 22, as Cactus pentagonus. 



Figure 14 is from a photograph taken by Paul G. Russell at Bahia, Brazil, in 1915. 



17. Cereus obtusus Haworth, Rev. PI. Succ. 70. 1821. 



Low, branching at base, dull green slightly glaucous; branches at first strongly ribbed, but in 

 age simply angled; ribs on young growth separated by deep intervals, obtuse, 2 to 2.5 cm. high, with 

 long grooves running down from the areoles; areoles i to 2 cm. apart; spines acicular, yellowish; 

 radial spines usually 5 to 7 ; central spine i ; flower and fruit unknown. 



Type locality: Not cited. 



Distribution: South America, presumably Brazil. 



The above description is drawn from a plant sent from the Edinburgh Botanical 

 Garden to New York in 1902. 



Figure 15 is from a photograph of the specimen above mentioned. 



18. Cereus caesius Salm-Dyck in Pfeiffer, Enum. Cact. 89. 1837. 



Cereus jamacaru caesius Salm-Dyck in Fobe, Monatsschr. Kakteenk. 18: 90. 1908. 

 Piptanthocereus jamacaru caesius Riccobono, Boll. R. Ort. Bot. Palermo 8: 2,30. 1909. 



Branching at base; branches strongly angled; ribs 5 to 7, high, somewhat acute, repand; areoles 

 1.5 to 2.5 cm. apart; spines acicular, brown, the radials 8 to 10; central spines 4 to 7, similar to the 

 radials, 12 mm. long or less; flowers and fruit unknown. 



Type locality: Not cited. 



Distribution: Probably Brazil. 



This species was described from greenhouse plants of unknown origin; later these 

 were supposed to have come from South America, probably from Brazil. We have studied 

 a cutting received from the Berlin Botanical Garden. 



Cereus glaucus (Pfeiffer, Enum. Cact. 89. 1837) was published as a synonym of C. 

 caesius. Cereus laetevirens caesius (Forster, Handb. Cact. 400. 1846), published as a 

 synonym only, doubtless applies to this species. 



19. Cereus azureus Parmentier in Pfeiffer, Enum. Cact. 86. 1837. 



Cereus seidelii Lehmann in Salm-Dyck, Cact. Hort. Dyck. 1849. 200. 1850. 

 Cereus azureus seidelii E. Dams, Monatsschr. Kakteenk. 14: 157. 1904. 

 Piptanthocereus azureus Riccobono, Boll. R. Ort. Bot. Palermo 8: 225. 1909. 



Probably branching at base, bluish pruinose; branches elongated, slender, flexuous; ribs 6 or 

 7, obtuse, repand; areoles remote, with brown tomentum and grayish wool; radial spines 8 to 12, 



