OregonFlora: Balsamorhiza macrophylla vs. Balsamorhiza serrata

	Balsamorhiza macrophylla	Balsamorhiza serrata
	large-leaf balsamroot	serrate balsamroot
Stems	up to 35 cm, tomentose; from single taproot.	5–34 cm, sparsely villous-tomentose; from single taproot.
Leaves	lanceolate-oblong, 1-pinnately divided; pinnae toothed, with teeth only on lower margins; surfaces tomentose; basal leaves in 1–few rosettes; blades 12–22 × 6–8 cm; pinnae 10–36 mm wide; petioles 7–20 cm; cauline blades 1.5–5 × 0.3–0.9 cm; petioles 6–9 cm.	ovate-lanceolate, undivided to pinnatifid, rarely with some leaves pinnately compound; margins sharply serrate; tips apiculate; surfaces sparsely hispid; basal leaves in 1–few rosettes; blades 4.5–15 × 2–5.5 cm; pinnae (when present) 4–11 mm wide; petioles 1–9(13) cm, often one or more bract-like basal leaves present; cauline leaves of 1 pair (when present); opposite; blades 1–4(5.5) × 0.6–1.5 cm; petioles 2–5.5(6.5) cm.
Inflorescences	with 1 terminal head.	with 1 terminal head.
Involucres	14–18 × 25–30 mm.	13–15 × 10–30 mm.
Ray florets	14–16, yellow; rays 35–40 × 8–11 mm.	8–21, yellow; rays 13–24 × 4–9 mm.
Disc florets	~9 mm.	~8 mm.
Phyllaries	ovate-lanceolate, 20–25 × 5–6 mm; tips acuminate, tomentose.	linear-lanceolate, 11–18 × 2–4 mm; tips acuminate, sparsely to densely villous-tomentose.
Fruits	8–9 mm, glabrous.	6–7 × 1.5–2 mm, glabrous.
Paleae	10–12 mm.	11–12 mm.
2n	=100 ± 2.

	Balsamorhiza macrophylla	Balsamorhiza serrata
Distribution	[WildflowerSearch map] [BONAP county map]	[WildflowerSearch map] [BONAP county map]
Discussion	Dry, open areas. Flowering May–Jul. 700–1400 m. BW. ID; east to WY. Native. True B. macrophylla is a decaploid centered on the Wasatch Mountains in Utah and Idaho. The plants in Oregon and western Idaho are also high polyploids, but they differ morphologically from classic B. macrophylla in their denser pubescence and the shape of their leaves. These eastern plants have been given the name B. macrophylla var. idahoensis. However, further study will likely show that they have a different parentage than B. macrophylla s.s. The specific epithet “macrophylla” means large-leaved, as the leaves are much larger than those of the other members of section Balsamorhiza.	Dry open areas, serpentine. Flowering Apr–Jun. 600–2100 m. BR, BW, Col, ECas, Lava. CA, NV, WA. Native. Balsamorhiza serrata is distinct among members of the genus Balsamorhiza in generally having simple leaves with serrate margins and tapered (not sagittate) bases. Some plants have pinnately divided leaves. Further work may show that these plants are actually hybrids between B. serrata and B. hookeri or B. hispidula. Balsamorhiza serrata is known to hybridize with B. sagittata.
Source	Flora of Oregon, volume 2, page 200 Abigail (Abby) Moore	Flora of Oregon, volume 2, page 201 Abigail (Abby) Moore
Sibling taxa	B. careyana, B. deltoidea, B. deltoidea x Balsamorhiza sericea, B. hispidula, B. hookeri, B. incana, B. lanata, B. rosea, B. sagittata, B. sericea, B. serrata	B. careyana, B. deltoidea, B. deltoidea x Balsamorhiza sericea, B. hispidula, B. hookeri, B. incana, B. lanata, B. macrophylla, B. rosea, B. sagittata, B. sericea
Synonyms	Balsamorhiza hookeri var. idahoensis
Web links	Local floras: OR Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria, Turner Photog. WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Balsamorhiza serrata

large-leaf balsamroot

serrate balsamroot

Stems

up to 35 cm, tomentose; from single taproot.

5–34 cm, sparsely villous-tomentose; from single taproot.

Leaves

lanceolate-oblong, 1-pinnately divided;

pinnae toothed, with teeth only on lower margins;

surfaces tomentose;

basal leaves in 1–few rosettes;

blades 12–22 × 6–8 cm;

pinnae 10–36 mm wide;

petioles 7–20 cm;

cauline blades 1.5–5 × 0.3–0.9 cm;

petioles 6–9 cm.

ovate-lanceolate, undivided to pinnatifid, rarely with some leaves pinnately compound;

margins sharply serrate;

tips apiculate;

surfaces sparsely hispid;

basal leaves in 1–few rosettes;

blades 4.5–15 × 2–5.5 cm;

pinnae (when present) 4–11 mm wide;

petioles 1–9(13) cm, often one or more bract-like basal leaves present;

cauline leaves of 1 pair (when present); opposite;

blades 1–4(5.5) × 0.6–1.5 cm;

petioles 2–5.5(6.5) cm.

Inflorescences

with 1 terminal head.

Involucres

14–18 × 25–30 mm.

13–15 × 10–30 mm.

Ray florets

14–16, yellow;

rays 35–40 × 8–11 mm.

8–21, yellow;

rays 13–24 × 4–9 mm.

Disc florets

~9 mm.

~8 mm.

Phyllaries

ovate-lanceolate, 20–25 × 5–6 mm;

tips acuminate, tomentose.

linear-lanceolate, 11–18 × 2–4 mm;

tips acuminate, sparsely to densely villous-tomentose.

Fruits

8–9 mm, glabrous.

6–7 × 1.5–2 mm, glabrous.

Paleae

10–12 mm.

11–12 mm.

=100 ± 2.

Balsamorhiza serrata

Distribution

[WildflowerSearch map]

[BONAP county map]

[WildflowerSearch map]

[BONAP county map]

Discussion

Dry, open areas. Flowering May–Jul. 700–1400 m. BW. ID; east to WY. Native.

True B. macrophylla is a decaploid centered on the Wasatch Mountains in Utah and Idaho. The plants in Oregon and western Idaho are also high polyploids, but they differ morphologically from classic B. macrophylla in their denser pubescence and the shape of their leaves. These eastern plants have been given the name B. macrophylla var. idahoensis. However, further study will likely show that they have a different parentage than B. macrophylla s.s. The specific epithet “macrophylla” means large-leaved, as the leaves are much larger than those of the other members of section Balsamorhiza.

Dry open areas, serpentine. Flowering Apr–Jun. 600–2100 m. BR, BW, Col, ECas, Lava. CA, NV, WA. Native.

Balsamorhiza serrata is distinct among members of the genus Balsamorhiza in generally having simple leaves with serrate margins and tapered (not sagittate) bases. Some plants have pinnately divided leaves. Further work may show that these plants are actually hybrids between B. serrata and B. hookeri or B. hispidula. Balsamorhiza serrata is known to hybridize with B. sagittata.