wet meadows, bogs, and lake and stream banks at high altitudes. 

 It usually grows in full sunlight, frequently forming hummocks or 

 islands in bogs, and clumps or sometimes extensive patches in mead- 

 ows, where it is interspersed among patches of willows and blue- 

 berries. On very moist sites this shrub frequently occurs in mixture 

 with moss, the two forming a complete ground cover. 



Fortunately, alpine kalrnia, which is poisonous to domestic live- 

 stock, is very unpalatable and is seldom grazed unless animals are 

 forced to eat it. Moreover, much of the range where it is found is too 

 wet and boggy to be grazed. These facts, and the short seasonal use 

 of these subalpine areas by livestock, fortunately reduce the possi- 

 bilities of its being extensively harmful. Clawson 1 and Fleming 2 

 have proved experimentally that alpine kalmia leaves are poisonous 

 to cattle, sheep, and goats, with sheep the most susceptible. The 

 lethal dose was not determined. However, the various feedings indi- 

 cated that 0.3 percent of a sheep's weight in green foliage is toxic 

 to that class of livestock, although as much as 2 percent was fed 

 without causing death. Fleming (op. tit.) found that as little as 

 9 ounces sometimes caused poisoning of calves. His experiments 

 indicated that the toxicity varies with the season and locality, but 

 Clawson's work has thus far not supported this conclusion. Clawson 

 describes the symptoms of alpine kalmia poisoning as "principally 

 weakness and nausea, accompanied with salivation and vomiting, 

 (which) may develop within less than 3 hours after a toxic dose has 

 been eaten, or they may not be apparent for 14 hours or more. 

 Poisoned animals may remain ill for more than 2 days and still 

 recover." 



The slender, branched, numerous stems of alpine kalmia arise from a root- 

 stock, either singly or in a group. The practically stalkless (sessile) leaves 

 are confined to the upper third of the branches, and are dark green above, 

 whitish below, one-half to 1 inch long, and vary in shape from elliptic-oblong 

 to oval, but appear narrower because the edges tend to roll downwards and 

 inwards. The rose-purple, showy flowers are borne on erect, slender stalks in 

 small terminal clusters. The pollen sacs (anthers) of the stamens are cauglit 

 in depressions or pouches, giving the stalks (filaments) an elastic bend, so 

 that when disturbed by an insect they spring out and dust its body with 

 pollen. The small, somewhat globe-shaped seed pod (capsule) splits to dis- 

 charge the seeds and eventually sheds its wall, but the center sometimes per- 

 sists on the flower stem for another season. 



Alpine kalmia is a dwarf shrub, from 4 to 12 (usually 6 to 8) inches high, 

 with small, turned-under (revolute) leaves. It is frequently confused in the 

 books with bog kalmia (K. polifolia, syns. K. glauca, K. occidentalis) , which 

 is a low, straggling shrub up to 28 inches in height, extending from New- 

 foundland and Labrador to Alaska, northern California, Manitoba, the Great 

 Lakes region, and northern New Jersey. In contrast, alpine kalmia has an 

 exclusively western range, and. appears to be much more common than bog 

 kalmia on western forest ranges. It was first published by the British bot- 

 anist Hooker as a variety, K. fflauea miorophylla,, and was raised to specific 

 rank by Heller in 1808, under the name K. mAorophyttq (Hoou.) Heller. 

 Rehder 8 later separated this into two varieties: K. polifolia, microphylla 

 (Hook.) Rehder, having the leaves mostly elliptical and scarcely revolute, and 

 K. polifolia, rosmarinifolia Rehd., with linear, strongly revolute leaves. Until 



1 Clawson A B ALPINE KALMIA (KALMIA MICROPHTLLA) AS A STOCK-POISONING PLANT. 

 U. S. Dept. Agr. Tech. Bull. 391, 10 pp., illus. 1933. 



2 Fleming, C. E. PROJECT 22. POISONOUS RANGE PLANTS. Nev. Agr. Expt. Sta. Ann. 

 Kept. 1919 :' 39-43. 1920. 



3 Rehder, A. MANUAL OF CULTIVATED TREES AND SHRUBS HARDY IN NORTH AMERICA . . . 

 930 pp., illus. New York. 1927. 



