Cornus unalaschkensis
Cornus subg. Arctocrania
alaskan bunchberry, western bunchberry, western cordilleran bunchberry
erect, green, 6–22 cm, appressed-hairy;
nodes 4–6, internodes progressively longer distally;
branches only at distalmost node, much shorter than distal internodes so stems appear unbranched.
and leaves opposite, leaves at distalmost node appearing whorled in some species.
at proximal 2–4 nodes nonchlorophyllous, opposite, ± scalelike, caducous (rarely chlorophyllous at 3d node from apex but much smaller than more distal leaves), at 2d node from apex nonchlorophyllous proximally, chlorophyllous distally, opposite, well developed, persistent, at distalmost node chlorophyllous, appearing to be in whorl of 6, well developed, persistent;
distalmost leaves much bigger than those at 2 more proximal nodes;
petiole 0–3.4 mm;
blade ovate to elliptic, 3.5–8 × 0.9–4 cm, apex acute or short acuminate, abaxial surface pale green, hairs sparsely appressed-hairy, adaxial surface green, appressed-hairy;
secondary veins 3 per side, all arising from proximal 1/2.
20–40-flowered;
peduncle 13–30 mm;
primary branches 0–2 mm;
bracts greenish white or white, often red-tipped, unequal, 2 ovate, 21–30 × 12–13 mm, 2 suborbiculate, 17–1.9 × 13–16 mm, apex acuminate.
congested cymes;
bracts 4, well developed, petaloid, subtending inflorescence.
0.4–1.6 mm, sparsely appressed-hairy or glabrous.
present.
hypanthium cream to mottled purple, 1.2–2 mm, densely appressed-hairy;
sepals mottled purple and cream, 0.1–0.4 mm, apex rounded or acute, thick, sparsely hairy on margin, densely glandular;
petals cream proximally, purple distally, 1.5–1.8 mm, apical awn 0.4–0.6 mm;
nectary dark purple or black.
10–20 per inflorescence, red, globose, 6–8 mm;
stone globose or subglobose, 2.7–3.4 × 2.1–3.4 mm, longitudinally grooved, apex slightly pointed.
distinct;
stone apex rounded.
= 44.
Cornus unalaschkensis
Cornus subg. Arctocrania
Species definitions within subg. Arctocrania have been controversial, reflecting an apparently complicated history of post-glacial range shifts, hybridization, and polyploidization in these long-lived clonal plants (Z. E. Murrell 1994). Many treatments (for example, E. Hultén 1937; J. A. Calder and R. L. Taylor 1965) had broad concepts of Cornus suecica and especially C. canadensis, and considered the intermediates to be hybrids, sometimes calling them C. ×intermedia (Farr) Calder & Roy L. Taylor. J. F. Bain and K. E. Denford (1979) recognized C. unalaschkensis as a tetraploid species derived from hybridization between C. canadensis and C. suecica and the remaining intermediates as C. canadensis ×C. suecica. C. Gervais and M. Blondeau (2003) applied the name C. ×lapagei Gervais & Blondeau to these hybrids. A morphometric analysis by Murrell showed five morphological groups: the morphological extremes, C. canadensis and C. suecica; the tetraploid intermediate species, C. unalaschkensis; and two groups of intermediates that were considered introgressive hybrids between C. canadensis and C. suecica (or perhaps rarely between one of these species and C. unalaschkensis); that treatment is followed here.
Species 3 (3 in the flora).
Identification of many specimens may be difficult because of the relatively high frequency of introgressants (approximately half of specimens examined by Z. E. Murrell 1994). Some intermediates are found in places where Cornus canadensis and C. suecica currently occur somewhat close together in Alaska, British Colombia, Greenland, Newfoundland and Labrador, Northwest Territories, Nova Scotia, Quebec, and St. Pierre and Miquelon. However, plants that mostly resemble C. canadensis but have petals that are purple on their distal third or chlorophyllous leaves at the second node from the apex (and non-chlorophyllous scale leaves at the third node), and sometimes only opposite leaves, are found at scattered locations throughout the range of C. canadensis but far from the current range of C. suecica, apparently reflecting the presence of the latter in the past (Murrell).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Petals cream; leaves at 2d node from apex non-chlorophyllous, scalelike; sepals cream, membranous, apices rounded. | C. canadensis |
1. Petals purple or cream proximally, purple distally; leaves at 2d node from apex chlorophyllous or non-chlorophyllous proximally and chlorophyllous distally, well developed; sepals purple or mottled purple and cream, thick, apices rounded or acute. | → 2 |
2. Petals purple; hypanthium very sparsely hairy; distalmost leaves similar size to those at 2 more proximal nodes. | C. suecica |
2. Petals cream proximally, purple distally; hypanthium densely hairy; distalmost leaves much larger than those at 2 more proximal nodes. | C. unalaschkensis |
BC
OR
WA
CalFlora
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
