102 



THE CACTACEAE. 



21. Lemaireocereus dumortieri (Scheidweiler) Britton and Rose, Contr. U. S. Nat. Herb. 12: 425. 

 1909. 



Cereus dumortieri Scheidweiler, Hort. Beige 4: 220. 1837. 

 Often tree-like, 6 to 15 meters high, the trunk proper short, 6 to 10 dm. long, 3 dm. in diameter 

 or more, woody; branches many, erect almost from the first, with numerous constrictions, very 

 pale bluish green or somewhat glaucous; ribs generally 6, sometimes 5 or 7, occasionally 9 on very 

 old joints; areoles elliptic, approximate or often confluent, gray -felted; spines various in number 

 and in length, 10 to 20 radials, 1 central or more, the longer ones often 4 cm. long, all at first straw- 

 colored but in age blackened ; flowers 5 cm. long, the tube and ovary bearing small ovate scales with 

 bunches of felt and occasionally bristles in their axils, the limb about 2.5 cm. broad; fruit oblong, 

 small, 3 to 4 cm. long, reddish within, not spiny, its areoles nearly contiguous, felted; seeds brown- 

 ish, 1.5 mm. long, dull, roughened. 



Type locality: Incorrectly given as Buenos Aires (see note below). 



Distribution: Central Mexico. 



Our description is drawn from numerous specimens collected by Dr. Rose in central 

 Mexico. This is the plant which passes as Cereus dumortieri in collections, but from the 

 description alone one can hardly be certain. It ranges over a considerable territory, but is 

 never abundant, being found generally as large iso- 

 lated individuals on the sides of rocky hills and cliffs. 



Greenhouse plants much resemble Pachycereus 

 marginatus, and both species have small flowers; 

 but the wild plants are very unlike and the fruit 

 and seeds differ widely. 



Although Scheidweiler in his original descrip- 

 tion of this species referred it to "Buenos Ayres," 

 he doubtless made a mistake, as he must have done 

 in his reference of Mammillaria obconella in the 

 same publication. The original description does 

 not correspond to any known South American 

 cactus, but does represent fairly well our central 

 Mexican species which passes under this name. 

 In 1845 the species was listed by Salm-Dyck (Cact. 

 Hort. Dyck. 1844. 30) as from the Belgian Gar- 

 dens (H. Belg.). In 1850 (Cact. Hort. Dyck. 

 1849. 210) he published an original description 

 apparently based on the Belgian specimens; but 

 evidently he had forgotten the older publication. 

 Schumann and most writers since 1850 have 

 assigned Prince Salm-Dyck 

 as the author of this spe- 

 cies. Weber (Diet. Hort. Fig. 153.— Lemaireocereus dumortieri. 



Bois 279. 1895) seems to 



have been the first botanist to refer the species to Mexico. 



Cereus anisacanthus De Candolle (Mem. Mus. Hist. Nat. Paris 

 17: 116. 1828) is doubtfully referred here by Schumann. If it 

 should prove to be the same, it would, of course, supplant the 

 present name. Its two varieties, ortholophus and subspiralis (De 

 Candolle, Mem. Mus. Hist. Nat. Paris 17: 117. 1828), so far as we can determine, belong 

 here also. 



This species is anomalous in Lemaireocereus, having very small flowers and spineless 

 fruit, but the scales of the ovary sometimes subtend bristles, if not spines, in their axils. 

 Illustration: Hort. Beige 4: pi. 15, as Cereus dumortieri. 



Fig. 152. — Fruit of Lemaire- 

 ocereus dumortieri. Xo.8 



