664 GENTIANACEAE 



spreading; corolla blue, about 4 cm. long, open-funnelf orm ; lobes obovate, obtuse 

 or acute; lobes cti the plaits 2-cleft, often laciniate, half as long as the corolla-lobes. 

 G. puberula Michx. Prairies: Ohio — Ga. — Kans. — Sask. Plain. 



7. PLEUROGYNE Eschsch. Marsh Felwort. 



Low slender annuals. Leaves opposite, entire. Flowers perfect. Calyx 

 deeply 4- or 5-cleft. Corolla rotate, 4- or 5-cleft, its divisions acute, with a pair 

 of scale-like appendages on their base. Stamens inserted on the base of the 

 corolla; anthers introrse, versatile. Style none; stigmas decurrent on the sutures; 

 ovary 1-celled. Capsule lanceolate or oblong, not stipitate. Seeds numerous. 



1. P. fontana A. Nels. Glabrous annual, 1-4 dm. high, with erect branches; 

 leaves linear, thin, with strong midrib and faint lateral ribs, 2-2.5 cm. long; 

 flowers in narrow racemes or panicles, pentamerous; sepals linear, 3-nerved; 

 corolla whitish, about 12 mm. long, often slightly shorter than the sepals; lobes 

 oblong, acute. P. rotata tenuifolia Griseb. Bogs in the mountains: Alta. — 

 Colo. Mont. — Subalp. Jl-Au. 



8. SWERTIA L. 



Simple-stemmed, caulescent perennials. Leaves opposite or some alternate. 

 Flowers perfect, blue or rarely white, in a thyrsoid inflorescence. Calyx 4- or 

 5-parted. Corolla rotate, usually 5-parted, each division bearing a pair of nectar- 

 iferous pits; lobes convolute in the buds. Stamens inserted on the base of the 

 corolla. Style very short or none; stigma 2-lobed; ovary 1-celled; capsule ovate; 

 placentae not- intruded. Seeds large, flat, commonly margined. 



Inflorescence elongate; coroUa-lobes linear or oblong. 



Leaves with -i-o parallel ribs from the base. 1. S. parallela. 



Leaves not parallel-ribbed. 



Petals not spotted; basal leaf-blades much longer than the petioles. 



2. S. scopulina. 

 Petals spotted; basal leaf-blades not longer than the petioles. 3. S. Fritillaria. 

 Inflorescence congested; corolla-lobes oval-elUptic. 4. S. congesta. 



1. S. parallela Greene. Stem about 3 dm. high; lower leaves 10-15 cm. 

 long, oblong-oblanceolate or oblong-elliptic; upper stem-leaves oblong, sessile, 

 opposite; inflorescence narrow; corolla lurid-purple; lobes lance-oblong, obtuse, 

 about 1 cm. long; glands with rather long fringe. Mountains: Mont. — Ida. 

 Mont. Jl. 



2. S. scopulina Greene. Stem 1-3 dm. high; basal leaves and lower stem- 

 leaves alternate, 10-15 cm. long, thin, oblong or elliptic to oblanceolate, obtuse, 

 pinnately- veined ; upper stem-leaves opposite, eUiptic or lanceolate, sessile; 

 corolla dark blue or purple; lobes Knear to oblong, obtuse, about 1 cm. long; 

 glands orbicular with short, subulate appendages. S. palustris A. Nels. Moim- 

 tains, in wet places: Mont. — Colo. — Utah. Mont. — Subalp. Jl-Au. 



3. S. Fritillaria Rydb. Stem 1.5-3 dm. high; basal leaves and lower stem- 

 leaves alternate, 6-10 cm. long, thin, obovate-spatulate, rounded at the apex; 

 middle and upper stem-leaves all alternate or a single pair of opposite ones, 

 oblanceolate or oblong; corolla-lobes lanceolate, mostly acute, greenish white 

 along the midrib and azure along the margins, all over dotted with dark blue 

 spots; glands inconspicuous, with rather long blue fringes. Wet places in canons: 

 Utah. Mont. Au. 



4. S. congesta A. Nels. Stem about 1 dm. high; basal leaves and lower 

 stem-leaves alternate, 5-10 cm. long, elliptic to oblanceolate, feather- veined, 

 obtuse; upi)er stem-leaves usually a single pair, opposite, oblong, sessile; corolla 

 dark bluish i)uri)lc; lobes obtuse or emarginate, 8-10 mm. long; glands cup- 

 shaped, with long ai)pendages; stamens surroimded by a ring of setae. Swales: 

 Wyo.— Utah— Ida.— Mont. Mont.— Alp. Au. 



9. FRASERA Walt. American Columbo. 



Perennial herbs, with hollow stems and taproots. Leaves opposite or more 

 often whorled, entire, thickish. Flowers perfect, in terminal paniculate cymes. 



