Eurybia
aster
ascending to erect, usually simple, rarely branched proximally, glabrous or ± densely hairy, usually eglandular, sometimes stipitate-glandular.
basal and cauline; alternate;
sessile or petiolate;
blades cordate, ovate, obovate, elliptic, or oblong to spatulate, oblanceolate, or lanceolate, usually gradually reduced distally, margins entire or serrate, sometimes spinulose-serrate, faces glabrate to hairy, usually eglandular, sometimes stipitate-glandular.
cylindro-campanulate to broadly campanulate, (4–14(–16) ×) 4–25+ mm.
flat to slightly convex, pitted, epaleate.
5–60, pistillate, fertile;
corollas white to purple (coiling at maturity).
8–260, bisexual, fertile;
corollas yellow, becoming purple at maturity, barely to abruptly ampliate, tubes shorter to longer than funnelform to campanulate throats, lobes 5, usually erect to spreading, sometimes ± reflexed, deltate, triangular, or lanceolate;
style-branch appendages lanceolate.
20–140 in 3–7 series, 1-nerved (usually rounded adaxially, sometimes low-keeled), broadly ovate or oblong to oblanceolate, lanceolate, or linear, unequal, bases indurate (rarely wholly foliaceous), margins narrowly scarious (seldom herbaceous), often ciliolate (green zones ± basally truncate), in distal 1/3–3/4 of phyllary (outer) to less than 1/6 and only along midnerves (inner), apices obtuse to acute, faces glabrous, ± strigillose, puberulent, scabrellous, strigoso-villous, or villous, sometimes ± stipitate-glandular.
radiate, usually in corymbiform arrays, rarely borne singly.
cylindro-obconic to fusiform, ± compressed, 7–12(–18)-nerved, faces glabrous or sparsely to densely strigillose, eglandular;
pappi persistent, of 35–70+, reddish, orange, cinnamon, tawny, tan, yellowish, or pinkish, unequal, soft to stiff, barbellate or barbellulate, often apically ± clavate bristles in 2–4 series.
= 9.
Eurybia
Species 23 (23, including 1 hybrid, in the flora).
Eurybia traditionally has been treated within Aster in a broad sense. G. L. Nesom (1994b), in his review of North American asters, showed that Aster in a broad sense does not form a natural group and proposed splitting it into several genera, among which Eurybia is one. In his treatment, Nesom included Herrickia within Eurybia, as sect. Herrickia in subg. Eurybia. Such views were generally supported in molecular phylogenetic studies (J. C. Semple et al. 2002). L. Brouillet et al. (2004) showed, however, that Oreostemma, Herrickia, Eurybia, and Triniteurybia form a grade at the base of the Machaerantherinae and that Herrickia and Eurybia are distinct.
The subgenera and sections proposed by G. L. Nesom (1994b), based on anterior taxonomy, could not be confirmed in the molecular studies cited above. I chose not to use subgeneric limits as proposed by Nesom because they may not reflect actual relationships. For instance, there is a clear gradation between members of sect. Calliastrum (Torrey & A. Gray) G. L. Nesom (subg. Eurybia) and sect. Heleastrum (de Candolle) G. L. Nesom. Also, I do not recognize sect. Eryngiifoliae (Alexander) G. L. Nesom distinct from sect. Heleastrum, as there is no clear demarcation between the two as currently defined. Finally, sect. Radulini (Rydberg) G. L. Nesom appears artificial to me, but currently there is no good way to reassign its species. The Eurybia radulina complex of western North America clearly constitute a group, but it is unclear whether the western E. conspicua or the eastern E. radula and E. saxicastelli are close to them. Members of other sections may have played a role in the reticulate evolution of sect. Eurybia, even though it is well marked by its cordate leaves and disc florets with long tubes and short, campanulate corollas. Therefore, species are described below in a rough taxonomic order, with diploids listed before polyploids of the same group.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Basal and/or proximal cauline leaves (at least some) cordate; e North America | → 2 |
1. Basal and/or proximal cauline leaf blades not cordate | → 10 |
2. Peduncles and involucres ± stipitate-glandular | → 3 |
2. Peduncles and involucres usually eglandular | → 5 |
3. Rays white; phyllaries sparsely stipitate-glandular; adaxial leaf faces villous, eglandular | E. schreberi |
3. Rays deep to pale purple; phyllaries sparsely to densely stipitate-glandular; adaxial leaf faces sparsely strigose or sparsely puberulent, stipitate-glandular | → 4 |
4. Proximal cauline leaf blades broadly ovate to ovate, bases cordate; innermost phyllaries appressed, usually to 7 mm | E. macrophylla |
4. Proximal cauline leaf blades ovate to elliptic-ovate, bases rounded to cordate; innermost phyllaries longer than 7 mm, at least some apically reflexed, ± squarrose, or twisted | E. ×herveyi |
5. Phyllaries (at least some) squarrose | → 6 |
5. Phyllaries not squarrose | → 7 |
6. Phyllaries usually 46–75(–90), oblong-lanceolate; ray florets (7–)16–20(–30), white or lavender; disc florets 20–40 | E. mirabilis |
6. Phyllaries 36–50, ovate, elliptic, or lanceolate; rays 7–15, blue or violet; disc florets 20–25 | E. jonesiae |
7. Leaf faces abaxially scabrous, adaxially hirsute, veins prominent; rosettes absent in spring | E. furcata |
7. Leaf faces abaxially sparsely strigose to villous or glabrous, adaxially glabrescent to sparsely strigose or villous, veins not prominent; rosettes present in spring, persistent or withering by flowering | → 8 |
8. Clones with sterile rosettes (on short rhizomes); proximal cauline leaf blades broadly ovate to ovate, bases cordate, sinuses broad, margins usually with 15–30 teeth per side; peduncles sparsely to moderately villous | E. schreberi |
8. Clones lacking sterile rosettes; proximal cauline leaf blades ovate, bases cordate, sinuses narrow or none, margins usually with 6–15 teeth per side; peduncles ± densely villous | → 9 |
9. Peduncles to 1.5 cm; involucres (3.5–)4.2–6(–7.5) mm; ray florets 5–10(–12), laminae (5–)10–15 mm; disc florets 12–19(–25) | E. divaricata |
9. Peduncles usually more than 1.5 cm; involucres 6.5–9(–10) mm; ray florets (8–)12–16(–20), laminae (10–)17–18(–20) mm; disc florets (12–)17–26 | E. chlorolepis |
10. Leaf blades linear, ± grasslike, often coriaceous, often parallel-nerved or obscurely nerved, margins entire or ± spinose-serrate (se United States) | → 11 |
10. Leaf blades lanceolate or elliptic- or lanceolate-ovate to ovate, oblong to narrowly elliptic, oblanceolate to obovate or spatulate, not coriaceous or if ± coriaceous, not linear with margins entire, serrate or spinulose-serrate | → 15 |
11. Stems villous; phyllaries 70–140; ray florets 25–60, white to pinkish; disc florets 115–260 | E. eryngiifolia |
11. Stems glabrous or glabrescent proximally, ± villous or strigillose distally; phyllaries 20–80+; ray florets 8–35, pale to dark purple; disc florets 18–60 | → 12 |
12. Distal stems villous to glabrescent; phyllaries 20–40, ± loose, not spreading; ray florets 8–17 | E. spinulosa |
12. Distal stems strigillose, villoso-hirsute or hirtello-puberulent; phyllaries 30–65+, ± spreading or reflexed; ray florets 8–35 | → 13 |
13. Distal stems hirtello-puberulent; heads usually in corymbiform arrays, sometimes borne singly; involucres 7–9 mm; rays 8–25; pappus bristles fine | E. avita |
13. Distal stems strigillose to villoso-hirsute; heads usually in spiciform or corymbiform arrays, rarely borne singly; involucres 8–12 mm; rays 15–35; pappus bristles coarse | → 14 |
14. Distal stems strigillose; heads borne in spiciform arrays, sometimes corymbiform terminally; outer phyllaries sometimes coriaceous, margins scabrous or scabroso-ciliate | E. hemispherica |
14. Distal stems strigillose to ± villoso-hirsute; heads borne in corymbiform arrays; outer phyllaries not coriaceous, margins densely ciliate proximally (indurate part), distally scabrous (foliaceous part) | E. paludosa |
15. Peduncles and phyllaries stipitate-glandular | → 16 |
15. Peduncles and phyllaries eglandular (or only peduncles sparsely stipitate-glandular) | → 19 |
16. Leaves cauline (w North America) | E. conspicua |
16. Leaves basal and cauline | → 17 |
17. Stems hispido-villous distally; leaf margins entire; mid cauline leaf bases auriculate-clasping; heads in elongate, racemo-corymbiform arrays, branches ascending; w United States | E. integrifolia |
17. Stems sparsely strigose, hispido-villous, or villous distally; leaf margins entire to ± serrate; mid cauline leaf bases attenuate to slightly clasping; heads in open, corymbiform arrays; e United States | → 18 |
18. Basal leaf blades ovate, bases broadly rounded (to cordate); mid and distal cauline leaf margins serrate; involucres (6–)7–11 mm | E. ×herveyi |
18. Basal leaf blades lanceolate or elliptic to ovate- or obovate-elliptic or spatulate, bases attenuate; mid and distal cauline leaf margins usually entire, sometimes crenulate-serrulate; involucres 7.5–14(–16) mm | E. spectabilis |
19. Leaves basal and cauline, only midnerves conspicuous; cauline leaf margins entire or slightly serrate, teeth and apices indurate (e United States) | → 20 |
19. Leaves cauline, ± markedly veined; cauline leaf margins usually ± serrate, sometimes entire, teeth sometimes ± indurate, apices not indurate | → 21 |
20. Rootstocks: thick, woody, ovoid to spheric caudices; stems usually ± densely villous distally; involucres 6.5–9 mm; phyllaries 24–35; ray florets (5–)8–14; disc florets 10–20, tubes longer than throats | E. compacta |
20. Rootstocks: rhizomes herbaceous becoming woody, slender, scaly; stems strigose or villoso-strigose or hirsuto-strigose distally; involucres 7–11(–13) mm; phyllaries 35–65; ray florets 13–30; disc florets 25–40, tubes shorter than throats | E. surculosa |
21. Plants in clones; distal stems ± villosulous; leaf margins ± recurved; e North America | → 22 |
21. Plants clumped; distal stems villous or villosulous to lanate; leaf margins not recurved; w North America. | → 23 |
22. Plants 10–100 cm, distally glabrescent to ± villosulous; mid cauline leaf blades lanceolate, oblanceolate, narrowly obovate, or narrowly elliptic, 10–42 × 3–8 mm, ± remotely, ± deeply serrate; rays purple | E. radula |
22. Plants 40–120 cm, distally villosulous; mid cauline leaf blades broadly elliptic to oblanceolate, (70–)90–140 × 40–50(–60) mm, coarsely serrate; rays white to pale purple | E. saxicastelli |
23. Plants 10–70 cm; stems ascending to erect, ± densely villous distally; leaves coarsely serrate (teeth mucronate), cauline bases often ± clasping; phyllaries not purplish, margins not purple; rays white (sometimes purplish) (w coast United States) | E. radulina |
23. Plants 1–50 cm; stems decumbent to ascending, villosulous or villous to ± lanate distally; leaves ± serrate to serrulate or entire, cauline bases subauriculate or slightly clasping; phyllaries ± purplish or margins purple; rays purple (sometimes pale) | → 24 |
24. Distal stems villosulous; leaf margins entire or serrulate; phyllaries unequal, margins purple, not squarrose or reflexed; mountains, s British Columbia, w United States | E. merita |
24. Distal stems villous to densely lanate; leaf margins serrate or entire; phyllaries subequal or barely unequal, purplish at least distally (but not only on margins), squarrose; w Canada, Alaska, Idaho, Montana | E. sibirica |
CA
OR
WA
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
