Amsonia subg. Articularia
usually branched for most of length (occasionally only distally).
on distal portions of inflorescences linear to narrowly deltate, mostly 2–6 mm (seldom less than 2 mm).
corolla tube (7–)8–12(–13) mm, moderately to strongly constricted just below apex, often in distinct narrow band (most visible just before anthesis);
stigma apiculate with 2 small lobes.
light reddish brown to pale brown, fusiform with acute to rounded-acute or flat-truncate (rarely diagonally truncate) ends, mostly smooth except at ends and with a prominent longitudinal groove.
moniliform, strongly constricted between seeds.
Amsonia subg. Articularia
Species 2 (2 in the flora).
Within subg. Articularia, as many as four species, one with two varieties, have been recognized. The most recent revision (S. P. McLaughlin 1982) recognized only one species with two varieties.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Stem leaf blades linear (ligulate or very narrowly elliptic), 1.6–3.5(–5.5) mm wide, surfaces moderately to sparsely tomentose; flowers purple to magenta, maroon, or lavender (blue); New Mexico, Texas. | A. arenaria |
1. Stem leaf blades ovate to narrowly lanceolate, narrowly to very narrowly elliptic, or elliptic, (3–)4–27 mm wide, surfaces glabrous or densely (rarely sparsely) tomentose; flowers bluish (violet- to lavender-tinged) to white (pinkish, bluish, or purple-tinged); Arizona, California, Nevada, Utah. | A. tomentosa |
