Frasera albicaulis
Frasera albicaulis var. nitida
white-stem elkweed, white-stem frasera
shining frasera, white-stem elkweed, whitestem frasera
1–few, with several rosettes.
glabrous.
blades narrowly white-margined;
basal oblanceolate, 4–23 × 0.3–1.2(–2) cm, basal leaves generally longer than lowest internode;
cauline leaves opposite, proximal blades oblanceolate to oblong, distal linear-oblong.
blades generally glabrous, except sometimes for puberulent sheathing bases of proximal leaves in Oregon and Washington plants.
narrow, 1.5–4(–5) cm wide, interrupted proximally, ± continuous distally.
calyx 3–7(–12) mm;
corolla greenish white to pale or medium blue, usually dark blue- to purple-dotted and/or with a dark blue, purple, or green central stripe (except in var. idahoensis), 6–12 mm, lobes oblong-obovate-elliptic, widest near midlength, abruptly tapering to acute to short-acuminate apex;
androecial corona scales present, variable among the varieties;
style slender, distinct;
nectaries and foveae 1 per corolla lobe, foveae distal to nectary, opening into an elliptic-oblong to lance-ovate differentiated area on the corolla surface, rim fringed all around but with fringes shorter distally, or not fringed toward distal end.
calyx glabrous;
corolla greenish white or pale to medium blue, generally with dark blue to purple spots;
corona scales oblong-lanceolate, 1–4 mm, margins deeply 2–several-lobed, rim of differentiated area on corolla surface fringed all around, fringes shorter near distal end.
Frasera albicaulis
Frasera albicaulis var. nitida
Varieties 5 (5 in the flora).
Frasera albicaulis varies in vegetative and abaxial corolla puberulence and in the size and dissection of the androecial corona. It has sometimes been divided into several species and additional varieties, but, from the material available for study at the time of this writing, it appears appropriate to recognize only five varieties, although F. ackermaniae might be considered for inclusion at varietal rank. Each of these varieties has a more or less distinct geographic range, but some intergrade.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Variety modocensis and var. nitida intergrade in northern California.
Plants from southeastern Washington and northeastern Oregon, treated as Frasera albicaulis var. columbiana by C. L. Hitchcock (1959), were said to be well isolated from var. nitida but scarcely separable. As variations overlap both in leaf-sheath puberulence and in the length of the corona scales, the characters by which these varieties were distinguished, these taxa are treated here as a single variety. If the plants in northeastern Oregon and southeastern Washington are distinguished taxonomically from var. nitida, the correct varietal epithet would be albida, based on its use in the combination F. nitida var. albida, which has priority at that rank over columbiana. As of this writing, the epithet albida has not been published at varietal rank under either Frasera or Swertia albicaulis.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Stems and abaxial or both leaf surfaces puberulent; rim of differentiated area on corolla surface not fringed at distal end. | → 2 |
2. Corona scales oblong, margins lacerate or deeply toothed, ultimate divisions threadlike. | var. albicaulis |
2. Corona scales ovate to obovate or oblanceolate, margins entire or shallowly 2–3-lobed, rarely absent. | var. modocensis |
1. Stems glabrous; leaf blades glabrous or puberulent only near base and abaxially along midvein; rim of differentiated area on corolla surface fringed all around, fringes shorter near distal end. | → 3 |
3. Corona scales ovate to elliptic, margins entire or shallowly undulate-erose or toothed. | var. cusickii |
3. Corona scales ovate to elliptic to oblong-lanceolate, margins lacerate or deeply lobed. | → 4 |
4. Corollas greenish white or pale to medium blue, generally with dark blue to purple spots; corona scales 1–4 mm, oblong-lanceolate. | var. nitida |
4. Corollas pale blue, usually without darker spots; corona scales 2–6 mm, widely ovate to elliptic. | var. idahoensis |
CA
OR
WA
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
