The growth behavior, ecology, and geography of Erythronium americanum in northeast North America

Abstract

During the spring months, 20%, on average, of the non-flowering bulbs of Erythronium americanum Ker. propagate by runners, yet in 2.5 ha of deciduous forest vegetation on heterogeneous terrain at Mont St. Hilaire, Quebec, the plant is either absent from or rare in places with standing water in April–May and on slopes steeper than 15°. Elsewhere in the stand, and particularly on ledges across the back slope and on the blowdown mounds of low gravel terraces, the plant is locally abundant. Field transplant experiments confirmed that the plant neither survives for long nor reproduces vegetatively outside its local range. Also, during five consecutive years of observation on the flora of sample quadrats in the stand, both the number of individuals of this species and their distribution did not significantly change, suggesting that the plant now occupies all suitable niches in the small study area. This may not be true elsewhere in southeastern Canada, where E. americanum is concentrated along the principal plant migration routes from the U.S.A. The plant occupies a much narrower range of topographic situations in Canada than in the U.S.A. and there are grounds for believing it could still be moving into valley bottom areas with a cover of hardwood forest vegetation in eastern and southern Nova Scotia, New Brunswick, the southern Laurentians, and extreme southwestern Ontario.