Frasera albicaulis
Frasera albicaulis var. albicaulis
white-stem elkweed, white-stem frasera
Douglas' frasera, white-stem frasera
1–few, with several rosettes.
densely puberulent.
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 abaxially puberulent.
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 lobes adaxially puberulent;
corolla pale to medium blue or greenish white to cream, generally with dark blue to purple spots;
corona scales oblong, deeply 2-lobed, often further cleft into threadlike segments, 1–3(–4) mm, margins lacerate or deeply toothed or lobed;
rim of differentiated area on corolla fringed proximally, not fringed toward distal end.
= 26 (as F. pahutensis).
Frasera albicaulis
Frasera albicaulis var. albicaulis
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.)
A report of Frasera albicaulis from British Columbia is unsubstantiated. California plants that have previously been included in var. albicaulis are treated here as var. modocensis.
The Nevada plants that were called Frasera pahutensis are disjunct by about 1200 km from other populations of F. albicaulis var. albicaulis. Although they occur nearer the ranges of var. modocensis and var. nitida, they resemble the more northern var. albicaulis in the narrow sense, differing, respectively, from the two varieties in California in their white or scarcely blue-tinged corollas, relatively small, deeply lacerate corona scales, and in their densely puberulent stems and leaves. Examination of numerous specimens by D. M. Post (unpubl.) and in studies for this flora has disclosed no morphological features by which the Nevada plants could be differentiated from var. albicaulis, although further study would be appropriate. The Nevada plants that have been called F. pahutensis may be diploid whereas some other taxa here included in F. albicaulis may be hexaploid, but with the ploidy level of var. albicaulis elsewhere being unknown and only one count having been published for any of the other components of F. albicaulis, it is not known which ploidy level prevails in which of the varieties. Additional studies of ploidy levels in this complex might indicate that further refinements in classification would be appropriate.
(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
