GENTIAN FAMILY 181 



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. interrupta. 



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

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



13. D. puberula. 



7. PLEUROGYNE Eschsch. Marsh Felwort. l. P. fontana. 



8. SWERTIA L. 



Inflorescence elongate; corolla-lobes linear or oblong. 



Leaves with 3-5 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. scnpulina. 

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

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



9. FRASERA Walt. American Columbo. l. F. fasiigiata. 



10. LEUCOCRASPEDUM Rydb. 



Scales between the stamens wanting (represented by merely hairs) ; corolla greenish yellow. 

 Basal leaves oblanceolate; lower stem-leaves linear. 1. L. albomarginatum. 



Basal leaves lanceolate; lower stem-leaves long-acuminate from an ovate base. 



2. L. utahense. 

 Scales between the stamens present, fruiged or cleft. 



Flowers creamy white; plant glabrous. 3. L. montanum. 



Flowers blue. 



Plant puberulent; inflorescence dense; interstaminal scales lanceolate. 



4. L. albicaule. 

 Plant glabrous; inflorescence more open; interstaminal scales obovate or orbicular. 



5. L. coeruleum. 



11. TESSARANTHIUM Kellogg. Deer's Tongue. 

 Corolla-lobes 18-22 mpi. long, usually exceeded by the long sepals. 



Plant glabrous; inflorescence simple with verticillate pedicels; basal leaves over 1 dm. 



wide. 1. T. macrophyllum. 



Plant puberulent; inflorescence compound; some branches simple, others again 



branched; basal leaves about 5 cm. wide. 2. T. scabrum. 



Corolla-lobes about 15 mm. long or less; inflorescence compound. 



Sepals narrowly linear, usually much exceeding the petals. 3. T. stenosepalum. 



Sepals linear-lanceolate or subulate, scarcely equalling the petals. 



Stem-leaves oblanceolate. 4. T. speciosum. 



Stem-leaves linear-lanceolate. 5. T. angustifolium. 



12. TETRAGONANTHUS .J. F. Gmel. Spurred Gentian. i. T. deflexus. 



Family 104. MENYANTHACEAE. Buckbean Family. 



1. MENYANTHES (Tourn.j L. Buckbe.an, Marsh Trefoil, Bog-bean. 



1. M. trifoliata. 



Family 105. APOCYNACEAE. Dogbane Family. 



Anthers unappendaged at the base, not connected with the stigma; flowers without a 

 disk; leaves alternate. 1. Amson'IA. 



Anthers appendaged at the base, converging around and coherent to the stigma; calyx- 

 tube partly attached to the gynoecium by means of a thick disk; leaves opposite. 



2. Apocynum. 



1. AMSONIA (Claj-t.) Walt. 

 Plant glabrous or nearly so. 



Sepals lanceolate, short-acuminate, a little more than 1 mm. long; pod not torulose. 



I. A. latifolia. 

 Sepals subulate, long-attenuate, 2-4 mm. long; pod more or less torulose or con- 

 stricted around the seeds. 



