Kalmia angustifolia
Kalmia angustifolia var. angustifolia
lambkill, sheep American-laurel, sheep-laurel
sheepkill
usually in whorls of 3, rarely alternate or opposite;
petiole 6–16 mm, usually puberulent;
blade oblong to elliptic-lanceolate, 1.5–8 × 0.5–2.5 cm, margins usually plane, apex obtuse to acute, usually apiculate, abaxial surface glabrous or puberulent, sometimes stipitate-glandular, adaxial lightly puberulent (hairs white, to 0.1 mm), sometimes glabrescent, midrib puberulent.
blades pale green abaxially, bright green adaxially, glabrous or with scattered, stipitate-glandular trichomes abaxially, usually not puberulent.
axillary near distal end, corymbiform racemes, 4–12-flowered.
5–20 mm.
sepals usually green, sometimes reddish apically or throughout, ovate, 2–2.8 mm, apex usually acuminate, surfaces puberulent;
petals connate nearly their entire lengths, usually reddish purple to pink, rarely white or bluish pink, usually deeper colored near anther pockets and with ring of red to purple spots just proximal to pockets, 7.5–9.5 × 6–13 mm, abaxial surface puberulent, adaxial glabrous, puberulent toward base;
filaments 2.5–3.5 mm;
style 3.5–4.5 mm.
calyx puberulent and densely stipitate-glandular;
corolla glabrous or slightly puberulent adaxially.
5-locular, 2–3.5 × 3–5 mm, puberulent, stipitate-glandular.
winged, obovoid, 0.6–1 mm.
= 24.
Kalmia angustifolia
Kalmia angustifolia var. angustifolia
Varieties 2 (2 in the flora).
The two varieties of Kalmia angustifolia are largely separate geographically and show different flavonoid profiles (S. Liu 1993). Southeastern Virginia has long been known as a region of overlap of these two entities; field and herbarium work (B. A. Sorrie and A. S. Weakley, unpubl.) has demonstrated that the two taxa retain their distinctiveness and that hybrids are rare. Sorrie and Weakley concluded that the two should be treated as separate species.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Variety angustifolia is well known as a weed in plantations of commercial shrubs such as blueberries and of timber trees. It is difficult and sometimes costly to control in the blueberry fields and it is on the Canadian weed list (I. V. Hall et al. 1973; A. A. Ismail and D. E. Yarborough 1981). Variety angustifolia has allelopathic effects on black spruce (Picea mariana) seedlings, and has a competitive advantage over them. It may have the same effects on balsam fir (Abies balsamea) or at least play a role in reducing the growth of that tree (A. U. Mallik 1987, 1993; Mallik and P. F. Newton 1988; E. B. Peterson 1965; I. D. Thompson and Mallik 1989; H. Zhu and Mallik 1994).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Calyces densely stipitate-glandular; leaf blade surfaces glabrous or scattered, stipitate-glandular trichomes. | var. angustifolia |
1. Calyces usually not stipitate-glandular; leaf blade surfaces densely puberulent abaxially, usually not stipitate-glandular. | var. carolina |
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