DIDTNAMIA. AXGTOSrERMIA. 0/ 



with the mar£;in ijiilected; lower concavo, oh- 

 soleiely o-toothed. unexpandcd. Jinthers un- 

 comK'cted: lobes unof|ual, divaricate. Capsule 

 strai.srld, cliiptir-ovatc, 2-celied, 2-vaIved, ma- 

 ijy-secded, opeDinj^ on both sidos; dissepiment 

 transverse. Seeds small, with an aiated lunate 

 margin. 



Annual; stem simple; leaves alternate, entire; flowers 

 axillary, alternate, sessile, and bracteate; bracles divari- 

 cately trifid. 



Species. 1, O. lumens. 



l^EscfiiPT. rjoot tortuous, perpendicular, and fibrous. 

 Stem simple, hirsutely pilose, terete. Leaves increasing 

 in size upwards, alternate, sessile, lanceolate-linear, 

 acute, entire, opaque, and as uell as the bractes and ca- 

 lix shortly and somewliat viscidly pubescent, margins sca- 

 brous; bractes cuneate, divaricately trifid, about an inch 

 long- and ihe same in width, 3-nerved. Calix much shor- 

 ter than the bractes, partly compressed, striated, sub- 

 campaniiktp, sej^ments line'ar-lanceolate, acute. Corolla 

 yellow, smooth; tube slender, about the length of the 

 calix; both of the lips concave, inflected, and closed, the 

 lower somewliat plaited and terminated by 3 minute den- 

 tures, so inconspicuous as to give the corolla the appear- 

 ance of being destiiute of an under lip. Stamina 4, small; 

 filaments capillary, ingrafted upon the upper lip a little 

 below tlie orifice, approximating by pairs under the same 

 lip; anthers pale, unusually small, 2-celled, cUsiincMy and 

 separately 2-lobcd, lobes pubescent, not jJarallel, one 

 acute-angularly diverging from below the stimmit of the. 

 otlier, almost exactly similar to the small lamdba of the 

 Greek al[)habet {\). Style filiform, stigma simple, minute. 

 Capsule elliptic ovate, obtuse, staight and pubescent, in- 

 cluded witiiln the C'<lix, 2-celled, 2-valved, many- seeded, 

 m:ir£;ins of the valves partly inflected; dissepiment trans- 

 verse, or origining from the middle of the valves and 

 seminiferous. Seeds small, more than 10, having an 

 aiated interrupted margin. Cotyledones 2, very small, 

 upon the growing plant, oval. H'ab. In humid situations 

 on the plains of the Missouri, near Fort Mandan; very 

 local. Flowering in July and August. Height about 12 

 or 14 inclies. Growing in quantities. Flowers of abright 

 and uniform yellow, almost of the size and form of the 

 common species of Melampijrum at first sight. In point 



