Kalmia microphylla

(Hooker) A. Heller

Bull. Torrey Bot. Club 25: 581. 1898 ,.

Common names: Western bog laurel
Endemic
Basionyms: Kalmia glauca var. microphylla Hooker Fl. Bor.-Amer. 2: 41. 1834
Synonyms: Kalmia polifolia subsp. microphylla (Hooker) Calder & Roy L. Taylor Kalmia polifolia var. microphylla (Hooker) Rehder
Treatment appears in FNA Volume 8. Treatment on page 484. Mentioned on page 481, 485.

Shrubs spreading to erect, 0.05–0.8 m. Twigs terete or slightly 2-angled proximal to node, viscid, glabrous or sparsely hairy. Leaves opposite; petiole absent or 0.1–2 mm, glabrous or puberulent; blade ovate or oval to broadly elliptic or lanceolate, 1.5–4 × 0.3–1.2 (–1.8) cm, margins plane to slightly revolute, apex obtuse to acute, abaxial surface puberulent, adaxial glabrous or sparsely puberulent towards base, midribs of both surfaces without purple, stipitate trichomes. Pedicels 10–30 mm. Inflorescences solitary flowers or terminal, corymbiform racemes, (3–) 6–12-flowered. Flowers: sepals light pink, pink, or light green, ovate, 2.7–3.6 mm, apex obtuse, surfaces glabrous, margins ciliate; petals connate ca. 1/2 their lengths, usually rose-purple, rarely white, 7–9 × 8–20 mm, glabrous, puberulent near base abaxially; filaments 3–4.5 mm; style 4.5–7 mm. Capsules 5-locular, 3.5–6 × 4–7 mm, glabrous. Seeds winged, oblong, 0.5–1.4 mm. 2n = 24.

Distribution

V8 945-distribution-map.gif

Alta., B.C., Man., N.W.T., Ont., Sask., Yukon, Alaska, Calif., Colo., Idaho, Mont., Nev., Oreg., Utah, Wash., Wyo.

Discussion

Varieties 2 (2 in the flora).

Kalmia microphylla is highly variable and has been treated as two species (J. K. Small 1914), two subspecies (R. L. Taylor and B. MacBryde 1978), or two varieties (J. E. Ebinger 1974). A flavonoid study (S. Liu 1993) indicated that the Pacific lowland (from Washington to Alaska) var. occidentalis populations are hardly separable from the alpine var. microphylla populations. The flavonoid data cited in support of combining K. microphylla and K. occidentalis are unpublished and impossible to judge. In any case, one would not expect varieties to necessarily differ chemically; the morphological and ecological differences seem sufficient.

The two varieties of Kalmia microphylla are generally distinct; var. microphylla is common in alpine meadows of western North America from California through the Rocky Mountains into northern Canada and Alaska. The elevations at which it is found range from an average 2500 meters (1500–3500 m) in California to an average 1700 meters (900–2200 m) in Alberta, British Columbia, and Washington. Variety occidentalis, in contrast, is always encountered growing below 900 meters, being common in coastal areas and islands off the coast of Alaska and British Columbia. These two varieties are known to hybridize (J. E. Ebinger 1974), and the hybrids are highly fertile and set large quantities of viable seed (R. A. Jaynes 1988).

Selected References

None.

Key

1 Leaf blades ovate or oval to broadly elliptic, 1.5 (-2.5) cm, to 2.5 times as long as wide; calyces 5-7 mm diam. Kalmia microphylla var. microphylla
1 Leaf blades lanceolate, 2-4 cm, 2.5-4 times as long as wide; calyces 7-10 mm diam. Kalmia microphylla var. occidentalis

"/2" is not declared as a valid unit of measurement for this property.

... more about "Kalmia microphylla"
puberulent +  and glabrous +
Obtuse (?) +  and Acute (?) +
Shunguo Liu +, Keith E. Denford +, John E. Ebinger +, John G. Packer +  and Gordon C. Tucker +
(Hooker) A. Heller +
furrowed +  and smooth +
not flaky +
Kalmia glauca var. microphylla +
1.2 cm12 mm <br />0.012 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (4 cm40 mm <br />0.04 m <br />) +
oval;broadly elliptic or lanceolate +
coriaceous +
0.3cm;1.2cm +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
Western bog laurel +
polypetalous +  and sympetalous +
rotate to crateriform campanulate cylindric globose or urceolate +
Alta. +, B.C. +, Man. +, N.W.T. +, Ont. +, Sask. +, Yukon +, Alaska +, Calif. +, Colo. +, Idaho +, Mont. +, Nev. +, Oreg. +, Utah +, Wash. +  and Wyo. +
undifferentiated +
fusiform +
0.3 cm3 mm <br />0.003 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
pendulous +  and erect +
subglobose;globose +
multicellular +
terminal +  and axillary +
persistent +
10-keeled +  and rotate +
plane;slightly revolute +
parietal +, axile +  and placentation +
tenuinucellate +  and unitegmic +
2-40-flowered +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
puberulent +  and glabrous +
reduced +
not sticky +
0.8 cm8 mm <br />0.008 m <br /> (2 cm20 mm <br />0.02 m <br />) +
puberulent +  and glabrous +
4-5-carpellate +
Bull. Torrey Bot. Club +
(3-)6-12-flowered +  and corymbiform +
distinct +
0.5mm +  and 1.4mm +
light green +, pink +  and light pink +
0.27 cm2.7 mm <br />0.0027 m <br /> (0.36 cm3.6 mm <br />0.0036 m <br />) +
procumbent +  and prostrate +
creeping +  and sprawling +
peltate +  and capitate +
straight +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
Kalmia polifolia subsp. microphylla +  and Kalmia polifolia var. microphylla +
Kalmia microphylla +
species +
hairy +  and glabrous +
2-angled +  and terete +
achlorophyllous +  and chlorophyllous +
evergreen +, deciduous +  and perennial +
heterotrophic +, autotrophic +  and mycotrophic +
spreading +  and erect +