CEBBUS. 33 



petals pure white, arranged like a cup. They open at about seven 

 o'clock in the evening, and fade the following morning. This 

 species was formerly cultivated in almost every collection of stove 

 plants, and its flowering in the autumn was looked upon as an 

 event, it being customary for the owner to invite his Iriends to 

 meet and watch the development of the flowers and enjoy their 

 delicious fragrance. Mexico, 1834. 



C. speciosissimus. 



Although neither night- flowering nor a climber, this species 

 may be included here, as it has fairly long angular stems, 

 grows quickly, and flowers freely ; also it may be grown satisfac- 

 torily as a wall plant. When well grown and flowered it is magni- 

 ficent. Specimens with thirty stems each (> feet high, and bearing 

 from sixty to eighty buds and flowers upon them at one time have 

 been grown in this country. The stems are three to five angled, 

 with tufts of spines set in little disks of whitish wool. The flowers 

 are 6 inches across ; tube 4 inches long ; their colour is an intense 

 crimson and violet, so bright as to dazzle the eyes when looked at 

 in bright sunlight. April and May. Mexico, 1820. It is said to 

 have been crossed with other species of Cereus, also with Phyllo- 

 cactus. Sir E. Antrobus is said to have exhibited specimens with 

 from 200 to 300 flowers each, and a large plant of it grown on the 

 back wall of a vinery at the Grange, Barnet, produced hundreds of 

 flowers every year. 



C. triangularis. 



This is easily recognised by its stout triangular stems. The 

 flowers measure 1 foot in length by about the same in width, and 

 are composed of a whorl of long narrow green sepals, with pale 

 brown points, a cluster of pure white petals, bright yellow stamens, 

 and a large club-like stigma ; they derelop in autumn. Mexico. 

 Flowered at Hampton Court in 1690. 



TRAILING SPECIES. 



These have thin, drooping or trailing stems. Some botanists 

 have made a separate genus for them, viz., Cleistocactus, but for 

 practical purposes they may be grouped under Cereus. Two of 

 them (C. flagelliformis and C. Mallisoni] are often grafted on 

 the stem of an erect Pereskia or on a climbing Cereus, such as 

 C. triangularis, in such a way as to hang from the roof of a house. 

 A large specimen of C. flagelliformis, growing from the climbing stem 

 of C. rostratus, was for a long time conspicuous in the Cactus-house 

 at Kew. 



C. flagelliformis. 



Sterns prostrate or pendent, | inch in diameter, round, with 

 numerous ridges almost hidden by many clusters of fine bristle-like 



D 



