910 CONTRIBUTIONS FROM THE NATIONAL HERBAEIUM. 



united with it except at the tip, elongate, at first straight, or in age somewhat 

 curved, the limb more or less oblique; perianth segments short, spreading or 

 reflexed ; filaments exserted ; style slender, exserted beyond the tube ; stigma 

 lobes narrow ; ovary with small scales bearing short felt and sometimes spines 

 in their axils; fruit capped by the withered flower, spiny or becoming smooth, 

 globular ; seeds of the typical species black, compressed, minutely pitted, with a 

 large basal oblique hilum. 

 Only two species are known. 



Ribs 5 to 8; flowers 4 to 10 cm. long 1. R. alamosensis. 



Ribs 4: flowers 12 cm. long 2. E. kerberi. 



1. Rathbunia alamosensis (Coulter) Britt. & Rose, Contr. U. S. Nat. Herb. 



12: 415. 1909. 



Cerexis alamosensis Coulter, Contr. U. S. Nat. Herb. 3: 406. 1896. 



Cereus sonorensis Riinge; Schum. Monatsschr. Kakteenk. 11: 135. 1901. 



Cereus pseudosonorensis Giirke, Monatsschr. Kakteenk. 20: 147. 1910. 



Sonora to Tepic ; type from Alamos, Sonora. 



Columnar, 2 to 3 meters high, at first erect but generally finally bent or 

 curved, 8 cm. thick or less, rooting at or near the tip and thus forming new 

 plants ; ribs 5 to 8, obtuse ; radial spines 11 to 18, spreading, straight, whitish ; 

 centrals 1 to 4, much stouter than the radials, 3 to 5 cm. long, porrect or as- 

 cending; flowers scarlet, 4 to 10 cm. long; scales on ovary small, acute or ob- 

 tuse, with a small tuft of felt and a few bristle-like spines in the axils, 

 those on the flower tube with a tuft of felt and sometimes with a spine ; tube 

 proper 1.5 cm. long; ovary tuberculate; fruit red, globular, 3 to 4 cm. in 

 diameter, naked or bearing scattered clusters of 5 or 6 white acicular spines. 

 " Sina," " cina." 



2. Rathbunia kerberi (Schum.) Britt. & Rose, Contr. U. S. Nat. Herb. 12: 



415. 1909. 



Cereus kerheri Schum. Gesamtb. Kakt. 89. 1897. 



Cleistocactvs kerberi Goss. Bull. Mens. Soc. Nice 44: 33. 1904. 



Type from Volcan de Colima. 



Columnar, somewhat branched, 2 meters high ; ribs 4, compressed ; radial 

 spines about 16, subulate; central spines 4, stouter than the radials, 4.5 cm. 

 long; flowers 12 cm. long; outer perianth segments linear-lanceolate, rose- 

 colored, reflexed ; stamens exserted ; scales on the ovary lanate in the axils. 



19. LOPHOCEREUS Britt. & Rose, Contr. U. S. Nat. Herb. 12: 42G. 1909. 



The genus consists of a single species. 



1. IiOph.ocereus schottii (Engelm.) Britt. & Rose, Contr. U. S. Nat. Herb. 

 12: 427. 1909. 



Cereus schottii Engelm. Proc. Amer. Acad. 3: 288. 1856. 



Cereus sargentianus Orcutt, Gard. & For. 4: 436. 1891. 



Cereus palmeri Engelm.; Coulter, Contr. U. S. Nat. Herb. 3: 401. 1896. 



Sonora and Baja California ; type collected near Magdalena, Sonora. 

 Southern Arizona. 



Usually branching only at base, forming large clumps sometimes with 

 as many as 50 or even 100 upright or ascending stems, 1 to 7 meters high ; 

 ribs usually 5 to 7, sometimes 9, separated by broad intervals ; bristles of 

 the flowering areoles numerous, straight, finely acicular, gray, 6 cm. long 

 or less ; flowerless areoles smaller, little felted, with 3 to 7 short subulate 

 spreading radial spines swollen at base and 1 or 2 central ones a little longer 



