The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

gray amsonia, woolly bluestar

Peebles' bluestar

Stems

erect, 11–65 cm, glabrous or tomentose;

branches usually borne on most of stem (occasionally confined to distal portion), well exceeding infructescence.

erect from vertical taproot, (15–)20–58(–90) cm, glabrous;

branches often borne below midpoint of stem as well as distally, uppermost often exceeding infructescence, often terminated by small inflorescences.

Leaves

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 0–1.2 mm, glabrous;

blades moderately heteromorphic;

stem leaf blades ligulate to narrowly oblong-elliptic or narrowly lanceolate, 3.2–7.3(–9.3) cm × 3–7(–9) mm, margins entire, not (slightly) revolute, not ciliate, apex acute, surfaces glabrous;

branch leaf blades linear to very narrowly oblong or lanceolate, 4.1–6.4(–7.4) cm × 1–4(–7) mm.

Flowers

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 narrowly deltate (subulate), (2–)3–6(–9.5) mm;

corolla tube purplish blue to greenish, darker and more bluish proximally, (13–)14–17(–19) mm, lobes white, (5–)7–9(–10) mm, outer surface of corolla glabrous.

Seeds

(8–)11–17 × (3–)3.9–5.5(–6.3) mm.

(5–)7–11 × 1.5–2.5 mm.

Follicles

erect (aberrantly deformed and spreading), 2–8(–9.5) cm × (4–)4.8–6.8 mm, apex acuminate, glabrous (partly tomentose).

erect, (2–)3–7(–10) cm × (2.5–)3–4 mm, apex acuminate, glabrous.

2n

= 22.

Amsonia tomentosa

Amsonia peeblesii

Phenology Flowering spring–early summer; fruiting summer.
Habitat Ridge tops, valleys, washes and draws, often on sand or sandstone.
Elevation 1300–1700 m. [4300–5600 ft.]
Distribution
map from USDA
sw United States
[WildflowerSearch map]
[BONAP county map]
map from FNA
AZ
[BONAP county map]
Discussion

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 peeblesii generally resembles narrower-leaved, glabrous forms of A. palmeri. The stems of A. peeblesii are much more often branched below the midpoint, and the flowers are usually larger; the distribution of A. peeblesii is narrower and more northerly, whereas A. palmeri is largely found in southern and western portions of Arizona.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Parent taxa Apocynaceae > Amsonia > subg. Articularia Apocynaceae > Amsonia > subg. Sphinctosiphon
Sibling taxa
A. arenaria, A. ciliata, A. fugatei, A. grandiflora, A. hubrichtii, A. jonesii, A. kearneyana, A. longiflora, A. ludoviciana, A. palmeri, A. peeblesii, A. rigida, A. tabernaemontana, A. tharpii
A. arenaria, A. ciliata, A. fugatei, A. grandiflora, A. hubrichtii, A. jonesii, A. kearneyana, A. longiflora, A. ludoviciana, A. palmeri, A. rigida, A. tabernaemontana, A. tharpii, A. tomentosa
Subordinate taxa
A. tomentosa var. stenophylla, A. tomentosa var. tomentosa
Key
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
Name authority Torrey & Frémont in J. Frémont: Rep. Exped. Rocky Mts., 316. (1845) Woodson: Bull. Torrey Bot. Club 63: 35. (1936)
Source FNA vol. 14. Treatment authors: Linh Tõ Ngô, Wendy L. Applequist. FNA vol. 14. Treatment authors: Linh Tõ Ngô, Wendy L. Applequist.
Web links