1. Corolla plicate in the sinuses, the plaits more or less extended into membranous 



lobes or teeth, or rarely essentially entire; calyx with an inter- 

 calycine membrane inside the tube, its lobes valvate; ovary bearing 

 nectariferous pits on its base (5) 



2(1). Flowers 4-merous, usually over 3 cm. long; inner sepals broader, mem- 

 branous-margined; corolla lobes fringed or toothed; corolla tube 

 without fringes on the throat (3) 



2. Flowers 5 (4) — merous, less than 2 cm. long; outer sepals broader; corolla 



lobes never fringed, rarely toothed; corolla tube with a fringe on 

 the throat (4) 



3(2). Flowers closely invested by a bractlike pair of upper leaves; stems not 

 over 15 cm. tall; perennial 1. G. barbellata. 



3. Flowers on naked peduncle and not invested by bractlike leaves; stems 



usually over 15 cm. tall; annual 2. G. detonsa. 



4(2). Flowers clustered; plants 3 dm. tall or more 3. G. Amarella. 



4. Flowers solitary; plants rarely more than 1 dm. tall 4. G. tenella. 



5(1). Dwarf annual or biennial; leaves broadly scarious-margined; flowers soli- 

 tary, terminal; anthers cordate, versatile; capsule long-stipitate and 

 exserted beyond corolla 5. G. Fremontii. 



5. Perennials; leaves not scarious-margined; flowers short-pedunculate (at least 



some of them axillary); anthers linear or oblong, extrorse; capsules 

 not long-stipitate nor exserted (6) 



6(5). Cauline leaves linear to linear-lanceolate; floral bracts linear; plait between 

 corolla lobes plane or somewhat lacerate (7) 



6. Cauline leaves ovate to elliptic or elliptic-lanceolate; floral bracts ovate to 



elliptic; plaits between corolla lobes somewhat erose or lacerate (8) 



7(6). Corolla 3.5-5 cm. long, white with blue markings; bracts shorter than the 

 flowers; plant rarely more than 15 cm. tall 6. G. algida. 



7. Corolla less than 3 cm. long, dark blue to purplish; bracts usually longer than 



the flowers; plant usually more than 20 cm. tall 7. G. Bigelovii. 



8(6). Corolla light blue to whitish; margins of leaves and calyx lobes con- 

 spicuously ciliolate; plaits about as long as corolla lobes, cut into 

 coarse broad segments 8. G. Saponaria. 



8. Corolla deep-blue; margin of leaves and calyx lobes scaberulous; plaits con- 



spicuously shorter than corolla lobes, cut into narrow fine segments 

 9. G. affinis. 



1. Gentiana barbellata Engelm. 



Perennial; stems single or in pairs from a slender fusiform root or caudex, 5-13 

 cm. tall; leaves rather thick and fleshy, obtuse, with rather rough callous margins; 

 basal leaves spatulate, 2-5 cm. long, slender-petioled; cauline leaves in 2 or 3 pairs, 

 linear-spatulate or the uppermost linear and connate at base; flowers 1 to 3, sessile 

 or nearly so between the involucrate foliaceous bracts; calyx lobes subulate- 

 triangular; corolla bright-blue, 2.5-3.8 cm. long, about twice the length of the 

 calyx, deeply 4-cleft; corolla lobes oblong, erose-denticulate above, conspicuously 

 fimbriate along the middle; capsule short and not stipitate; seeds squamulose- 

 roughened. Anthopogon barbellatus (Engelm.) Rydb. 



In wet meadows, on alpine and subalpine seepage slopes, and open coniferous 

 forests, in N. M. (Colfax, Taos and Rio Arriba cos.) and Ariz. (Coconino Co.), 

 Aug. -Sept.; Wyo. to N.M. and Ariz. 



2. Gentiana detonsa Rottb. 



Glabrous annual 1-4 dm. tall; stems usually several from the base, simple or 

 branched; leaves numerous in basal tuft, oblanceolate to spatulate, 1.5-4 cm. long; 



1322 



