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aster

Engelmann's aster, Engelmann's mountain-aster

Habit Perennials, 10–160 cm (usually cespitose, induments usually of stipitate-glandular and smooth-surfaced, curved or twisted woolly hairs, plants with caudices or short rhizomes, roots fibrous). Perennials 50–120(–150) cm (with caudices or stout rhizomes).
Stems

ascending or erect, simple, glabrate, puberulent, pilose, cottony, or woolly, eglandular or glandular.

ascending to erect, glabrate or pilose, eglandular to ± densely glandular.

Leaves

cauline; alternate;

sessile (proximal withering by flowering; proximalmost reduced, scalelike);

blades (1-nerved) ovate, elliptic, oblong, lanceolate, or linear (± uniform in size), margins entire, faces glabrate, scabrous, cottony, or woolly, eglandular or stipitate-glandular.

mid and distal blades elliptic to lance-ovate, 5–10 cm × 15–35 mm, faces glabrous and eglandular to adaxially villous and/or ± glandular.

Peduncles

often stipitate-glandular.

Involucres

turbinate-cylindric, turbinate, turbinate-obconic, or campanulate, 10–25 mm diam.

turbinate, 7–10 mm.

Receptacles

± flat, pitted, epaleate.

Ray florets

0–21 (usually 5, 8, or 13), pistillate, fertile;

corollas violet-purple, purple, pink, or white.

Disc florets

10–35, bisexual, fertile;

corollas yellow, ± ampliate, tubes shorter than funnelform throats, lobes 5, erect or reflexed, triangular;

style-branch appendages lanceolate.

Phyllaries

20–50 in 3–6 series, ± unequal (± appressed, often reddish or purplish at margins and tips), 1-nerved (keeled), ovate, lance-oblong, lanceolate, linear-oblong, or linear, chartaceous at bases, margins sometimes hyaline, especially proximally;

apices acute to obtuse, green, usually puberulent, tomentose, and/or stipitate-glandular, sometimes glabrous.

in 4–6 series (strongly unequal, often reddish apically), linear to lance-ovate, acute to acuminate, pubescent to glandular or glabrate abaxially, villous adaxially, especially distally (appearing ciliate toward tips).

Heads

radiate or discoid, usually in open, racemiform, paniculiform, or corymbiform arrays, sometimes borne singly.

5–15(–40) in racemiform to corymbiform arrays.

Cypselae

± obconic, flattened, laterally 1–2-ribbed, sometimes with 1–2 additional nerves on each face, glabrous, pilose, or strigose, eglandular;

pappi persistent, of 30–50 whitish to tawny, barbellate or smooth, apically clavate or more conspicuously barbellate bristles in 2(–3) series (outer usually 1 mm or less, sometimes 0, inner 5–10 mm).

usually pilose;

pappus bristles in 2 series, barbellate.

Rays

usually 8 or 13, white to pink.

x

= 9.

2n

= 18.

Eucephalus

Eucephalus engelmannii

Phenology Flowering Jul–Aug.
Habitat Open coniferous forests, montane and subalpine meadows
Elevation 500–3000 m [1600–9800 ft]
Distribution
from USDA
North America
[BONAP county map]
from FNA
CO; ID; MT; NV; UT; WA; WY; AB; BC
[WildflowerSearch map]
[BONAP county map]
Discussion

Species 10 (10 in the flora).

Eucephalus, a relatively well-marked western North American group, has been treated as a section of Aster or as a distinct genus. Recent molecular evidence places Eucephalus, together with the eastern North American Doellingeria, at the base of the North American clade of Astereae.

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

Forms of Eucephalus engelmannii from the Cascade Mountains with leaves more densely pubescent on the abaxial faces may reflect intergradation with E. ledophyllus.

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

Key
1. Ray florets usually 1–4, often 0
→ 2
1. Ray florets commonly 5, 8, or 13+
→ 5
2. Ray florets 0; leaves 5–9 cm, ± glabrous abaxially, glandular adaxially; plants 60–120 cm; open woods, Lane County, Oregon
E. vialis
2. Ray florets usually 1–4; leaves 2–6 cm, hairy; plants 10–100 cm
→ 3
3. Leaves glabrous or nearly so abaxially, moderately to densely hairy adaxially
E. tomentellus
3. Leaves glabrous, eglandular or sparsely glandular on both faces
→ 4
4. Phyllaries subequal
E. breweri
4. Phyllaries strongly unequal
E. glabratus
5. Stems, leaves, and phyllaries glabrous, glaucous; plants 40–160 cm; leaves linear tonarrowly lance-elliptic, 4–10 cm; rays purple
E. glaucescens
5. Stems, leaves, and phyllaries pubescent or glabrate, glandular or not, not glaucous; plants 10–120(–150) cm; leaves elliptic, oblong, lance-ovate, lance-elliptic, lanceolate, linear-oblong or -lanceolate, 1.5–10 cm; rays white, pink, violet, or purple.
→ 6
6. Leaves 5–10 cm, elliptic to lanceolate, glabrous and eglandular, or abaxially ± glandular and/or villous; plants 50–150 cm; rays white to pink
E. engelmannii
6. Leaves 1.5–7 cm, elliptic, elliptic-oblong, oblong, lance-ovate, lance-elliptic, linear-oblong or -lanceolate, glandular or not, scabrous or cottony; plants 10–80 cm; rays white or violet to purple
→ 7
7. Rays white; stems pilose or sparsely to moderately glandular-pubescent
→ 8
7. Rays violet to purple; stems scabrous (to scabrellous) or cottony and/or glandular-pubescent (especially peduncles)
→ 9
8. Phyllaries lance-ovate; Cascade Mountains, Oregon
E. gormanii
8. Phyllaries lance-linear; Olympic Mountains, Washington
E. paucicapitatus
9. Leaves moderately scabrellous (and sometimes glandular) on both faces
E. elegans
9. Leaves sparsely scabrous abaxially, strongly cottony adaxially
E. ledophyllus
Source FNA vol. 20, p. 39. Treatment author: Geraldine A. Allen. FNA vol. 20, p. 40. Treatment author: Geraldine A. Allen.
Parent taxa Asteraceae > tribe Astereae Asteraceae > tribe Astereae > Eucephalus
Sibling taxa
E. breweri, E. elegans, E. glabratus, E. glaucescens, E. gormanii, E. ledophyllus, E. paucicapitatus, E. tomentellus, E. vialis
Subordinate taxa
E. breweri, E. elegans, E. engelmannii, E. glabratus, E. glaucescens, E. gormanii, E. ledophyllus, E. paucicapitatus, E. tomentellus, E. vialis
Synonyms Aster section E., Aster subsection E. Aster elegans var. engelmannii, Aster engelmannii
Name authority Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 298. (1840) (D. C. Eaton) Greene: Pittonia 3: 54. (1896)
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