Amsonia longiflora
tubular bluestar
erect, 16–60 cm, glabrous or sparsely to moderately pubescent;
branches often borne on most of stem (or only distal portion), often remaining shorter than infructescence.
petiole 0–2.5 mm, glabrous or sparsely to moderately pubescent;
blades slightly heteromorphic;
stem leaf blades linear to ligulate (very narrowly elliptic or lanceolate), (2.3–)3–6.5(–9) cm × (0.7–)1–2.8(–5) mm, margins entire, sometimes somewhat revolute, ciliate or not, apex narrowly acute, surfaces glabrous or sparsely to moderately pubescent;
branch leaf blades linear, (1.1–)2.5–5.2(–7) cm × 0.5–1.3(–3) mm.
sepals narrowly deltate (to subulate) with weak, often curved apex, (2–)3.5–7(–9.5) mm;
corolla tube bluish to lead-colored, lavender or purplish below, often greenish above, (20–)28–41(–45) mm, lobes white to cream or bluish white (pale pink), (6.5–)9–13.5(–18) mm, outer surface of corolla glabrous.
5.3–8.1(–10.5) × 1.5–2.7 mm.
erect, (3.8–)6–11(–20) cm × (2.4–)2.9–4 mm, apex short-acuminate (acute), glabrous.
Amsonia longiflora
Varieties 2 (2 in the flora).
The varieties of Amsonia longiflora are distinguished by differing pubescence. Both are generally found on limestone substrates. Notes on a specimen collected by R. C. Sivinski (Sivinski 4282, UNM) indicate that var. longiflora was collected on dolomite and had pale blue corollas, whereas nearby var. salpignantha occurred on gypsum and had white to pale pink corollas (the latter is rarely reported, and corolla lobe color is not consistently different between the two varieties). It is not known whether this substrate preference may be consistent and contributes to maintaining the distinction between the two. Both are restricted to southern New Mexico and Texas, but var. longiflora is confined to a relatively small portion of western Texas, while var. salpignantha is more widely distributed in western Texas, and occurs also in several counties in a disjunct portion of central Texas.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Stems, leaves, petioles, and outer surface of calyces glabrous; leaf margins not ciliate, not revolute. | var. longiflora |
1. Stems, leaves, petioles, and outer surface of calyces usually sparsely to moderately pubescent (seldom glabrate to glabrous); leaf margins at least sparsely ciliate, occasionally somewhat revolute. | var. salpignantha |
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