242 GENTIANACE^E. (GENTIAN FAMILY.) 



3. A CERATES, Ell. GREEN MILKWEED. 



Perennial herbs, resembling Asdepias, but distinguished by the total absence 

 of horn or crest to the hoods. Flowers small, greenish or barely tinged with 

 purple. 



* Mass of anthers and stigma globular, not equalled by the hoods : column below 



the hoods evident : leaves mainly alternate-scattered, very numerous. 



1. A. auriculata, Engelm. Glabrous up to the inflorescence : stem 2 or 

 3 feet high, slender : leaves linear-filiform, with scabrous margins : umbels 

 several, lateral : column below the hoods very short : hoods oval or quadrate, 

 emarginately or sometimes 3-crenately truncate, the involute margins at base 

 appendaged with a pair of remarkably large and broad auricles : anther-wings 

 narrow and of equal breadth from top to bottom. Bot. Mex. Bound. 1 60. 

 From Colorado to New Mexico and S. Texas. 



* * Mass of anthers and stigma longer than broad, almost equalled by the hoods, 



the short insertion of which covers Hue. very short column : leaves often opposite, 

 mostly broader. 



2. A. viridiflora, Ell. Tomentose-puberulent : stem 1 or 2 feet high : 

 leaves oval or oblong and obtuse or retuse, or sometimes narrower and acute : 

 umbels 2 to 5 or sometimes solitary, dense, mostly lateral and subsessile: pedicels 

 little over twice the length of the reflexed narrowly oblong lobes of the greenish 

 corolla : hoods somewhat fleshy, with small auricles at base much involute and 

 concealed, alternated by as many short and roundish or gland-like small internal 

 teeth : anther-ivings semi-rhomboid above, with a much longer tapering base. 

 From Colorado to the Saskatchewan and eastward across the continent. 



3. A. lanuginosa, Decaisne. Hirsute rather than woolly : stems a span 

 or two high, terminated by a single pedunculate umbel: leaves frequently alter- 

 nate or scattered, from oblong-ovate to lanceolate, with roundish base : pedi- 

 cels 3 or 4 times the length of the oblong lobes of t/ie greenish corolla : hoods 

 purplish, obtuse and entire, involute auricles at base obscure if any : the alter- 

 nating internal teeth or lobes small and emarginate : anther-wings broadest and 

 obtusely angulate below the middle. From the head- waters of the Missouri to 

 Wisconsin and N. Illinois. 



ORDER 50. GENTIANACE2E. (GENTIAN FAMILY.) 



Smooth herbs, with a colorless bitter juice, opposite and sessile entire 

 and simple leaves without stipules, regular flowers with the stamens as 

 many as the lobes of the corolla, a one-celled ovary with two parietal 

 placentae, or nearly the whole ovary wall ovuliferous ; the fruit a many- 

 seeded capsule. Flowers cymose or simply terminal. lu all ours the 

 lobes of the corolla are convolute in the bud. 



* Style distinct and slender, deciduous : anthers twisting in age. 



1. Erythrsea. Parts of the flower 5 or 4. Corolla salverform. Anthers oblong or linear, 

 commonly exserted, twisting spirally in one or two turns after anthesis. Capsule 

 from oblong-ovate to fusiform. 



