242 GENTIANACE^E. (GENTIAN FAMILY.) 



3. ACERATES, Eil. Greex Milkweed. 



Perennial herbs, resembling Asclepias, 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-creuately 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. 160. 

 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 the 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-wings semi-rhomboid above, with a much longer tapering base. — 

 From Colorado to *he 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 oblonjj lobes of the 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. GENTIANACEJE. (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. In all ours the 

 lobes of the corolla are convolute iu the bud. 



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

 1. £rythrsea. Parts of tbe flower 5 or 4 Corolla salverfomi. Anthers oblong or linear, 

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

 from oblong-ovate to fusiform. 



