All Floras      Advanced Search
FNA Vol. 20 Page 13, 16, 39 Login | eFloras Home | Help
FNA | Family List | FNA Vol. 20 | Asteraceae

143. Eucephalus Nuttall, Trans. Amer. Philos. Soc., n. s. 7: 298. 1840.

Aster [Greek eu-, good or original, and kephalotos, with a head; alluding "to the elegant qualities of the calyx"—T. Nuttall 1840]

Geraldine A. Allen

Aster Linnaeus sect. Eucephalus (Nuttall) Munz & D. D. Keck ex A. G. Jones; Aster subsect. Eucephalus (Nuttall) Bentham

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). Stems ascending or erect, simple, glabrate, puberulent, pilose, cottony, or woolly, eglandular or 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. Heads radiate or discoid, usually in open, racemiform, paniculiform, or corymbiform arrays, sometimes borne singly. Involucres turbinate-cylindric, turbinate, turbinate-obconic, or campanulate, 10–25 mm diam. 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. 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. 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). x = 9.

Species 10 (10 in the flora): North America.

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.

1 Ray florets usually 1–4, often 0   (2)
+ Ray florets commonly 5, 8, or 13+   (5)
2 (1) Ray florets 0; leaves 5–9 cm, ± glabrous abaxially, glandular adaxially; plants 60–120 cm; open woods, Lane County, Oregon   10 Eucephalus vialis
+ Ray florets usually 1–4; leaves 2–6 cm, hairy; plants 10–100 cm   (3)
3 (2) Leaves abaxially moderately to densely hairy, adaxially glabrous or nearly so   9 Eucephalus tomentellus
+ Leaves glabrous, eglandular or sparsely glandular on both faces   (4)
4 (3) Phyllaries subequal   1 Eucephalus breweri
+ Phyllaries strongly unequal   4 Eucephalus glabratus
5 (1) Stems, leaves, and phyllaries glabrous, glaucous; plants 40–160 cm; leaves linear tonarrowly lance-elliptic, 4–10 cm; rays purple   5 Eucephalus glaucescens
+ 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 (5) Leaves 5–10 cm, elliptic to lanceolate, glabrous and eglandular, or abaxially ± glandular and/or villous; plants 50–150 cm; rays white to pink   3 Eucephalus engelmannii
+ 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 (6) Rays white; stems pilose or sparsely to moderately glandular-pubescent   (8)
+ Rays violet to purple; stems scabrous (to scabrellous) or cottony and/or glandular-pubescent (especially peduncles)   (9)
8 (7) Phyllaries lance-ovate; Cascade Mountains, Oregon   6 Eucephalus gormanii
+ Phyllaries lance-linear; Olympic Mountains, Washington   8 Eucephalus paucicapitatus
9 (7) Leaves moderately scabrellous (and sometimes glandular) on both faces   2 Eucephalus elegans
+ Leaves abaxially strongly cottony, adaxially glabrous or sparsely scabrous   7 Eucephalus ledophyllus

  • List of lower taxa


  •  |  eFlora Home |  People Search  |  Help  |  ActKey  |  Hu Cards  |  Glossary  |