Balsamorhiza macrophylla |
Balsamorhiza sericea |
|
---|---|---|
cutleaf balsamroot, Idaho balsamroot, large-leaf balsamroot |
silky balsamroot, silvery balsamroot |
|
Habit | Plants 30–45(–100) cm. | Plants 10–30(–40) cm. |
Basal leaves | green, ovate to lanceolate, 20–50+ × 8–15 cm (pinnatifid, lobes lanceolate, 20–80+ × 10–40 mm, entire or ± dentate), bases ± cuneate, ultimate margins usually entire (plane or weakly revolute, ciliate), apices obtuse to acute, faces scabrous or piloso-hirtellous to pilose (at least abaxial usually gland-dotted as well). |
blades silvery, lanceolate or lance-ovate, 9–30 × 2–7 cm (1-pinnatifid, lobes oblong to oblanceolate, 5–35 × 3–17 mm), bases cuneate, ultimate margins usually entire (plane or weakly revolute, obscurely, if at all, ciliate), apices rounded to acute, faces densely sericeous. |
Involucres | ± hemispheric, 20–30 mm diam. |
campanulate to hemispheric, 11–20+ mm diam. |
Ray laminae | 35–50+ mm. |
15–20 mm (adaxially puberulous on veins). |
Outer phyllaries | lance-ovate or lanceolate to lance-linear, 12–30(–40) mm, equaling or surpassing inner (margins ciliate), apices acute to attenuate. |
broadly ovate to triangular-ovate, 12–20 mm, slightly surpassing inner, apices acuminate to attenuate (margins not ciliate). |
Heads | usually borne singly. |
borne singly. |
2n | = 100 ± 2. |
|
Balsamorhiza macrophylla |
Balsamorhiza sericea |
|
Phenology | Flowering May–Jul. | Flowering Apr–May. |
Habitat | Deep soils, rocky meadows, sagebrush scrublands, conifer forests | Serpentine outcrops, among surface rocks, in crevices, hillsides, dry streamsides among cobbles |
Elevation | 1000–2400 m (3300–7900 ft) | 400–1800 m (1300–5900 ft) |
Distribution |
ID; UT; WY
|
CA; OR
|
Discussion | Balsamorhiza macrophylla is a high polyploid; it occurs sympatrically with B. sagittata. It evidently arose from hybridization between B. sagittata and B. hispidula. Balsamorhiza macrophylla has the multi-branched caudices and massive taproots of the former, and the leaf dissection of the latter. No hybrids with other species are known. Presumably, the high-polyploid chromosome complement precludes interbreeding. Plants of var. idahoensis are smaller, are known only from southwestern Idaho and northeastern Utah, and differ from var. macrophylla by being pilose, with strongly shaggy-pilose involucres. More study may determine that var. idahoensis merits specific rank. The Utah populations are not well understood and deserve attention. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Balsamorhiza sericea hybridizes with B. deltoidea. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 21, p. 98. | FNA vol. 21, p. 96. |
Parent taxa | Asteraceae > tribe Heliantheae > subtribe Ecliptinae > Balsamorhiza > subg. Balsamorhiza | Asteraceae > tribe Heliantheae > subtribe Ecliptinae > Balsamorhiza > subg. Balsamorhiza |
Sibling taxa | ||
Synonyms | B. hookeri var. idahoensis, B. macrophylla var. idahoensis | |
Name authority | Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 350. (1840) | W. A. Weber: Phytologia 50: 358. (1982) |
Web links |