GENTIANACEAE. 265 



Corolla with nectariferous glands, pits or scales. 



Style none ; leaves opposite, rarely alternate ; corolla without a crown at 



the base. 8. SWERTIA. 



Style manifest ; leaves in ours verticillate ; corolla with a crown at the base. 



9. FRASERA. 



i. ERYTHRAEA Neck. CENTAURY, CANCHALAGUA. 



i. Erythraea arizonica (A. Gray) Rydb. (E. calycosa arizonica A. Gray) 

 In sandy soil from Colo, and Utah to Ariz. Hotchkiss, Delta Co. 



2. EUSTOMA Salisb. 



i. Eustoma Russellianum (L.) Griseb. In wet meadows from Neb. and 

 Colo, to La. and N. M.; also Mex. Alt. 4000-5500 ft. Tobe Miller's ranch; 

 La Porte, Larimer Co. ; Ft. Collins ; Denver. 



3. ANTHOPOGON Neck. FRINGED GENTIAN. 



Annuals or biennials ; flowers on naked long peduncles terminating the branches, 



not bracteate. i. A. elegans. 



Perennials ; flowers short-peduncled in the axils of two bract-like leaves. 



2. A. barbellatus. 



1. Anthopogon elegans (A. Nels.) Rydb. (Gentiana elegans A. Nels.) In 

 wet places from Mackenzie to Colo, and Ariz. Alt. 8000-13,000 ft. Goose 

 Creek; Westcliffe; 4 miles west of Cameron Pass; White River Plateau; Twin 

 Lakes; McCoy; Columbine; Keblar Pass; North Park; near Pagosa Peak; 

 Grand Lake ; Mt. Bartlett ; Robinson ; Mt. Harvard ; North Park near Teller ; 

 Long's Peak ; Medicine Bow Mountains ; Chambers' Lake ; South Park at 

 Jefferson ; Breckenridge. 



2. Anthopogon barbellatus (Engelm.) Rydb. (Gentiana barbellata Engelm. ; 

 G. Moseleyi A. Nels.) In mountain meadows and in wet places on the peaks 

 of Colo. Alt. 9000-12,000 ft Mt. Harvard; Pike's Peak; Gentian Dell; 

 near Breckenridge; Gray's Peak; Vance Junction; Cameron Pass. 



4. AMARELLA Gileb. GENTIAN. 



Flowers solitary on long peduncles ; stems depressed, cespitose. 



i. A. monantha. 

 Flowers numerous, short-peduncled ; stems erect, leafy, more simple. 



Calyx-lobes very unequal ; two of them large, foliaceous, ovate or oval, much 

 broader than the rest and covering them. 2. A. heterosepala. 



Calyx-lobes somewhat unequal, but all oblong, lanceolate or linear. 



Flowers numerous, crowded, very short-peduncled ; the whole inflorescence 

 dense and spike-like ; leaves usually equalling or exceeding the internodes. 



3. A. strictiflora. 

 Flowers rather few, distinctly peduncled ; middle internodes elongated and 



usually longer than the leaves. 

 Larger sepals usually half as long as the corolla or longer ; plant stout, 



2-4 dm. high ; stem-leaves lanceolate. 4. A. scopulorum. 



Sepals less than half as long as the corolla; plant slender, 1-2, seldom 3 

 dm. high ; stem-leaves usually ovate-lanceolate. 5. A. plebeja. 



i. Amarella monantha (A. Nels.) Rydb. (Gentiana tenella A. Gray, in 

 part; not Rottb. ; G. monantha A. Nels.) In wet places of Colo. Alt. 8000- 

 12,000 ft. Mirror Lake; headwaters of Clear Creek, near Empire. 



