General Key to the Families 33 



III. Trientalis. L. 



I. T. arctica. Fisch. Star-flower. 



IV. DODECATHEON. L. 



I. D. pauciflorum. (Durand.) Greene. Shooting Star. 



ORDER XXIX. GENTIANALES 



LV. GENTIANACE^. GENTIAN FAMILY 



Smooth herbs with a bitter colourless juice; leaves opposite, 

 sessile, entire, simple, without stipules; flowers regular, perfect, 

 in clusters, axillary or solitary at the ends of the stems; fruit 

 usually a two-valved septicidal many-seeded capsule. 



I. Gentiana. (Tourn.) L. 



1. G. Macounii. Macoiin's Gentian. 



2. G. Amarella L. var. acuta. Michx. Northern Gen- 



tian. 



3. G. propinqua. Richards. Four-patted Gentian. 



4. G. arctophila. Alpine Gentian. 



5. G. prostrata. Haenke. Dwarf Gentian. 



6. G. affinis. Griseb. Large Gentian. 



7. G. glauca. Pale Gentian. 

 II. Halenia. Borkh. 



I. H. deflexa. (Sm.) Griseb. Spurred Gentian. 



SUBFAMILY MENYANTHOIDE^ 



III. Menyanthes. (Tourn.) L. 



I. M. trifoliata. L. Marsh Buckbean. 



LVI. APOCYNACE^. DOGBANE FAMILY 



Perennial herbs or shrubs, mostly with milky acrid juice ; leaves 

 entire, opposite or alternate, without stipules ; flowers regular,.,the 

 lobes of the corolla convolute and often twisted in the bud, calyx 

 free from the two ovaries which are distinct; fruit slender elon- 

 gated terete seed-pods, seeds often comose. 



I. Apocynum. (Tourn.) L. 



I. A. androsjemi folium. L. Spreading Dogbane. 



