662 GENTIANACEAE 



Seed-coats lamellose-rugose, the lamellae white, forming hexagonal areas; basal rosettes 



of leaves remaining at flowering time; perennials with short rootstocks. 

 Corolla 12-18 mm. long; leaves ovate or oval. 1. D. glauca. 



Corolla 3O-40 mm. long; leaves linear or linear-oblanceolate. 2. D. Romanzovii. 



Seed-coats smooth, but often produced into wings; basal rosettes none at flowering time; 



cespitose perennials. 



Corolla closed; lobes in ours obsolete or nearly so; limb as well as the plaits incurved. 



3. D. Andrewsii. 



Corolla open, campanulate ; lobes spreading or ascending. 

 Calyx-lobes broadly ovate or oval ; seeds wingless. 



Corolla-lobes rounded at the apex ; calyx-tube 5-6 mm. long. 4. D. obtusiloba. 

 Corolla-lobes acute; calyx-tube 7-10 mm. long. 



Leaves broadly ovate, usually obtuse at the apex and subcordate at the 



base; calyx-lobes obtuse. 5. D. calycosa. 



Leaves ovate or lance-ovate, acute at both ends; calyx-lobes acute. 



6. D. monticola. 

 Calyx-lobes linear, lanceolate, or none. 



Floral leaves more or less broadened and more or less scarious; seeds usually 



wingless. 7. D. Parryi. 



Floral leaves narrow, not scarious; seeds winged. 



Calyx-lobes erect or none; corolla-lobes ascending or nearly erect, not 



toothed; plaits equally lobed. 

 Flower-cluster dense, its branches, peduncles, and internodes very 



short. 



Leaves all except the floral ones ovate, oblong, or lanceolate. 

 Calyx-lobes well developed; calyx-tube truncate at the apex. 

 Leaves ovate or rarely lanceolate; calyx-lobes oblong or 

 oblong-lanceolate; corolla open-funnelform. 



8. D. oregana. 



Leaves oblong or lanceolate; calyx-lobes linear or linear- 

 lanceolate; corolla narrowly funnelform. 



9. D. affinis. 

 Calyx-lobes none or minute; calyx-tube irregular, more or less 



lobed or cleft. 10. D. Forwoodii. 



Upper stem-leaves linear or lance-linear. 



Plant erect, many-flowered; corolla nearly cylindraceous, 2-2.5 



cm. long. 11. D. Bigelovii. 



Plant decumbent, few-flowered; corolla funnelform, 2.5-3 cm. 



long, or more. 9. D. affinis. 



Flower-cluster lax, its branches, lower peduncles, and internodes 



elongate. 12. D. inter rupta. 



Calyx-lobes widely spreading, linear-lanceolate; corolla-lobes in anthesis 

 'strongly spreading, more or less denticulate; plaits unequally 2-lobed. 



13. D. puberula. 



1. D. glauca (Pallas) Rydb. Stem simple, 2-10 cm. high; basal leaves 

 rosulate, oval or obovate, 0.5-1.5 cm. long, rather fleshy; stem-leaves 2-3 pairs, 

 oval or obovate, about 1 cm. long; calyx-tube 5-6 mm. long; lobes lanceolate, 

 about 1.5 mm. long; corolla blue; lobes ovate, obtuse; lobes of the plaits ovate, 

 entire. Gentiana glauca Pallas. Arctic-alpine situations: Alaska B.C. Mont.; 

 e Asia. Subalp. Alp. Jl-Au. 



2. D. Romanzovii (Ledeb.) Rydb. Basal leaves many, linear-oblanceojate 

 to narrowly linear, 3-10 cm. long; stem-leaves linear or linear-oblong, 2.5-5 cm. 

 long; stem 5-10 cm. long; calyx-tube 12-15 mm. long; lobes linear-oblong, obtuse, 

 5-10 mm. long; corolla yellowish white, tinged with blue and purple-dotted; 

 lobes triangular, acute; plaits entire, with a very broadly triangular summit. G. 

 frigida A. Gray, not Haenke. G. Romanzovii Ledeb. Arctic-alpine situations: 

 Alaska Utah Colo. Mont. Mont. Alp. Jl-Au. 



3. D. Andrewsii (Griseb.) Small. Stem glabrous, simple, 3-6 dm. high, 

 leafy; leaves lanceolate or ovate-lanceolate, 7-15 cm. long, 3-7-ribbed; flowers 

 in terminal clusters and in the axils of the uppermost leaves; calyx-tube 8-12 mm. 

 long; lobes lanceolate or ovate, ciliolate, spreading; corolla broadly clavate, 

 bluish or white, closed; lobes obsolete, rounded; lobes of the plaits rounded, erose, 

 yellowish. G. Andrewsii Griseb. Wet meadows and among bushes: Que. Ga. 

 Nev Neb. S.D. Plain. Au-O. 



4. D. obtusiloba Rydb. Stems erect or ascending, about 1 dm. high; 

 internodes short, equalling or a little longer than the leaves; leaves very broadly 

 ovate, 3-5-ribbed, usually acute at the apex and subcordate at the base; calyx- 

 tube 5-6 mm. long; lobes broadly oval, rounded at the apex, often overlapping, 

 about 8 mm. long; corolla dark blue, about 3.5 cm. long; lobes of the plaits about 

 half as long as the corolla-lobes. High mountains: Mont. Submont. Jl-Au. 



