﻿50 plants: fendlerianj:. 



downwards ; the 2 or 3 central curved spines are directed upwards, and 6 to 8 or 9 lines 

 long, the middle one shorter or wanting. The lower central spine is the longest (10 to 

 14 lines) and broadest, being from 1 to H line wide. Flowers pearly white, 12 to 13 

 lines long, 12 to 15 lines in diameter. Lower sepals membranaceous; the upper herba- 

 ceous in the middle. Petals about two lines wide. 



246. Cereus viridiflorus, Engelm. in Wisliz. Rep. not. 8, sub Echinocereo. East- 

 ern mountains of Santa Fe, on sunny, rocky declivities ; flowering in May and June. — 

 I have seen specimens brought from other parts of New Mexico, of much larger size than 

 than those of Fendler or Wislizenus, some of them 1J inch in diameter and 3 to 4 

 inches high, some with stout central spines, others entirely destitute of them.* 



* After a careful revision of the characters which distinguish my genus Echinocereus ( Wisl. Rep. note 7) 

 from Cereus proper, I think it most natural to unite the two. Echinocereus will then constitute the first sec- 

 tion of Cereus, and comprise those of low stature and mostly of csespitose growth, having diurnal flowers with 

 short tubes (and almost straight embryos with very small cotyledons). It appears to comprise Prince Salm 

 Dyck's (ined.) first two sections, viz. : 1. Lophogoni, and 2. Sulcali ; but perhaps not all of the latter. Those 

 known to me as belonging to New Mexico, Chihuahua, and Texas, may be divided into two sections, viz. : — 



<5> 1. Costati : caule 4- 10-costato ; aculeis radialibus pi. m. porrectis non pectinatis ; areolis orbiculatis. 



A. Tuberculis subdistinclis. 



1. C proctjmbens (sp. nov. ined.) : tuberculis 4 - 5-serialibus ; aculeis brevibus tenuibus, 5-6 radialibus, 1 



centrali. — Matamoras. 



B. Tuberculis in costas confluentibus. 



* Aculeis plus minusve teretibus. 



2. C. coccineus, Engelm. in Wisl. Rep. not. 9. Costis 9- 11 ; aculeis radialibus 9- 10, centrali 1 recto. 



3. C. polyacanthus, Engelm. 1. c. not. 28. Costis 10 ; aculeis radialibus 10- 12, centr. 4 rectis. 



4. C. Rcemeri (sp. nov. ined.) : Costis 7 - 9 ; aculeis radialibus 8, centrali 1 recto. — Western Texas. 



5. C. Fendleri (sp. nov. supra) : Costis 9- 10, aculeis radialibus 7, centrali 1 curvalo. 



• * Aculeis compressis, angulatis. 



6. C. ENNEACANTHtrs, Engelm. 1. c. not. 46. Costis 10 ; aculeis radialibus 8, centrali 1 recto. 



7. C. triglochidiatus, Engelm. I. c. not. 9. Costis 6-7; aculeis 3-6 subcurvatis. 



§2. Sulcati: caule sinubus 10-24 parum incisis sulcato; areolis pi. m. elongatis ; acul.rad. pectinato-connatis. 



8. C. dasyacanthus, Engelm. 1. c. not. 19. Septdec. - octodecim-sulcatus ; aculeis radialibus subporrectis, 



centralibus radiales subasquantibus, pluribus deflexis. 



9. C. RDFisPiNtJS, Engelm. 1. c. not. 31. Undecim-sulcatus ; aculeis rad. adpressis variegatis elongatis, 

 centrali 1 robusto. 



10. C. adustus, Engelm. 1. c. not. 29. Tredecim- 15-sulcatus ; aculeis rad. pectinatis albidis adustis, centrali 



nullo seu 1 robusto. The last form is /3. radians (Echinocereus radians, Engelm. 1. c. not. 30). 



11. C. viridiflorus, Engelm. 1. c. not. 8. Tredecim-sulcatus ; aculeis rad. pectinatis variegatis, centrali 



nullo seu 1 robusto. 



12. C. pectinatus, Scheidw. sub Echinocacto ; Engelm. 1. c. not. 45, sub Echinocereo : Octodecim-23-sul- 



catus ; aculeis radialibus pectinatis, centralibus 2-5 brevissimis. 



13. C. cesfitosus, Engelm. in PL Lindh. Tredecim - 18-sulcatus ; aculeis rad. pectinatis, centrali nullo. 



