Amsonia tomentosa
Amsonia grandiflora
gray amsonia, woolly bluestar
Arizona bluestar
erect, 11–65 cm, glabrous or tomentose;
branches usually borne on most of stem (occasionally confined to distal portion), well exceeding infructescence.
erect, 38–80(–90) cm, glabrous;
branches borne on distal part of stem, at least slightly exceeding infructescence.
petiole 1–5 mm, glabrous or tomentose (leaves rarely sessile);
leaf blades slightly or moderately heteromorphic;
stem leaf blades ovate to narrowly lanceolate, narrowly to very narrowly elliptic, or elliptic, (2–)3–5(–6) cm × (3–)4–27 mm, margins entire, not revolute, not ciliate, apex acute (somewhat acuminate), surfaces glabrous or densely (rarely sparsely) tomentose;
branch leaf blades narrower than stem leaf blades, (2.2–)3–4.7(–5.6) cm × (2–)3–6(–13) mm.
petiole 0–3(–5) mm, glabrous;
blades somewhat heteromorphic or all linear;
stem leaf blades linear to ligulate or very narrowly lanceolate to very narrowly elliptic, (5.5–)7–12(–14) cm × (2.5–)3–6(–8) mm, margins entire, sometimes slightly revolute, sparsely ciliate, apex narrowly acute, surfaces glabrous;
branch leaf blades linear, (4.8–)5.5–9(–10) cm × (1–)1.5–2.6(–3.1) mm.
sepals subulate or narrowly deltate (deltate), (2–)3.5–6(–7.5) mm;
corolla tube green to purplish or pinkish green, (7–)8–12(–13) mm, lobes bluish (violet- to lavender-tinged) to white especially after anthesis (pinkish, bluish, or purple-tinged), (2.8–)4.5–8 mm, outer surface of corolla glabrous.
sepals subulate to narrowly deltate, often weak and curved, (3–)4.5–6.5(–7) mm, glabrous;
corolla tube blue (to whitish), 16–21.5 mm, lobes bluish to white, turning blue with age (pinkish), 9.5–14(–16) mm, outer surface of corolla glabrous.
(8–)11–17 × (3–)3.9–5.5(–6.3) mm.
6.4–11 × 2–3 mm.
erect (aberrantly deformed and spreading), 2–8(–9.5) cm × (4–)4.8–6.8 mm, apex acuminate, glabrous (partly tomentose).
erect, 4–12(–15) cm × 3.1–4(–4.5) mm, apex acuminate, glabrous.
Amsonia tomentosa
Amsonia grandiflora
Varieties 2 (2 in the flora).
Both varieties of Amsonia tomentosa have an unusual pattern of variation in pubescence. Stems and leaves are usually either densely tomentose or glabrous, with intermediate density of pubescence rare. In some populations, the two forms are found together, suggesting that indument may be a single-gene trait.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Amsonia grandiflora is primarily restricted to Pima and Santa Cruz counties and rarely extends to Maricopa County and adjacent regions of Mexico. In Mexico, it is largely or entirely restricted to the state of Sonora; it reportedly rarely occurs in Durango, but no specimen was seen. It may be distinguished from A. palmeri by its larger flowers. Fruiting specimens of A. grandiflora will typically have somewhat shorter leaves than narrow-leaved individuals of A. palmeri, and the sepals are on average longer.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Stem leaf blades ovate to lanceolate (narrowly elliptic to elliptic), (6–)8–27 mm wide, branch leaf blades markedly narrower, 4–13 mm wide; w, s Arizona, California, Nevada. | var. tomentosa |
1. Stem leaf blades narrowly to very narrowly elliptic or narrowly lanceolate, (3–)4–8(–10) mm wide, branch leaf blades slightly narrower, (2–)3–6(–7) mm wide; n Arizona, Utah. | var. stenophylla |
CA
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