180 GENTIAN ACEAE 



Corolla enclosed in the ventricose wing-angled calyx. 1. A. ventricosus. 



Corolla much longer than the merely angled calyx. 



Inner calyx-lobes ovate, fully twice as broad as the outer linear-lanceolate ones; 

 stem-leaves linear. 

 Filaments hairy at the middle. 2. A. Macounii. 



Filaments glabrous. 3. A. tonsus. 



All calyx-lobes lanceolate, the inner not twice as broad as the outer ones; stem- 

 leaves oblong or lanceolate. 

 Inner calyx-lobes decidedly broader than the outer; corolla-lobes distinctly 



fringed on the sides. 4. A. thermalis. 



Inner calyx-lobes sUghtly broader than the outer; corolla-lobes dentate, rarely 

 with a few bristles on the side,s. o. A. simplex. 



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



6. A. barbeUatus. 



4. AMARELLA Gilib. Gentian. 



Corolla with a fringed crown in the throat; glands at the base of the corolla obsolete or 

 wantmg. 

 Flowers solitary on 2-10 cm. long peduncles; stems depressed, cespitose. 



1. A. monantha. 

 Flowers nimierous, short -peduncled; stem erect, more leafy, simple at the base. 



Calyx-lobes very unequal, the outer two large, foliaceous, ovate or oval, much 

 broader than the rest. 2. A. heterosepala. 



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

 Stem-leaves lanceolate or broader. 



Flowers numerous, crowded, very short-pedicelled, the whole inflorescence 

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

 internodes. 3. A. strictiflora. 



Flowers comparatively few, distinctly pedicelled; middle internodes elon- 

 gate and usually longer than the leaves. 

 At least the outer calyx-lobes lance-oblong; stem-leaves, except the 

 uppermost, oblong or oval, obtuse. 4. A. anisoscpala. 



Calyx-lobes linear or linear-lanceolate; stem-leaves lanceolate or ovate- 

 lanceolate, acute. 

 Larger calyx-lobes usually half as long as the corolla oi longer; plant 

 stout, 2-4 dm. high; stem-leaves lanceolate. 5. A. scopulnrum. 

 Calyx-lobes less than half as long as the corolla; plant slender, 1-2 dm., 

 seldom 3 dm. high; stem-leaves usually ovate-lanceolate. 



6. A. plebeia. 

 Stem-leaves linear or linear-lanceolate. 7. A. tortuosa. 



Corolla without a crown; glands at the base of the corolla evident. 



Corolla-lobes obtuse or merely acute, not cuspidate; leaves narrowly Unear-lanceolate. 



8. A. ventorum. 

 Corolla-lobes cuspidate-tipped. 



Stem-leaves lanceolate, rarely ovate-lanceolate; corolla-lobes lanceolate to ovate. 



9. A. propinqua. 

 Stem-leaves ovate; corolla-lobes broadly ovate. 10. A. arctophila. 



5. CHONDROPHYLLA A. Xels. Moss Gentian. 



Leaves and calyx-lobes with broad scarious margins ; capsule long-stipitate, at last exserted 



from the corolla. 1. C. Fremontii. 



Leaves and calyx-lobes slightly scarious-margmed ; capsule short-stipitate, not e.xserted. 



2. C. americana. 



6. DASYSTEPHANA Adans. Gentian. 



Seed-coats lamellose-rugose, the lamellae wliite, 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 30-40 nun. long; leaves linear or hnear-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; Umb 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 romided 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 Unear, 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. 



Caly.x-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 develoi)ed; calyx-tube trmicate at the apex. 



