LES CYPÉRACÉES DE L'ÎLE ANTICOSTI: CAREX ET KOBRESIA

Abstract

Sixty-two species, seven hybrids, eleven varieties, and two forms of Carex, and one species of Kobresia occur on Anticosti, a 135-mile long island located in the mouth of the St. Lawrence River.After a few historical notes on the early surveys of the Anticosti flora, the author lists in their natural order the different species of Carex occurring on the island, consisting mainly of collections made by Macoun, Schmitt, Frère Marie-Victorin, and his field-associate F. Rolland-Germain, and Jacques Rousseau. Each species has its respective distribution and proper bibliography given. Two new hybrids are described.In the third part, the author gives some phytogeographical conclusions. The sedges enumerated fail in the following categories:1. Arctic-alpine species at their southernmost limit or nearly so: Kobresia simpliuscula, Carex microglochin, and C. rupestris.2. Euryatlantic species, i.e. species occurring on both sides of the Atlantic, but very often with their main area in Europe: C. Hostiana, C. demissa, C. Hartmani, C. flava.3. Species of the upper subarctic: C. capillaris, C. rariflora, C. media, etc.4. Species of the lower subarctic: C. exilis, C. atratiformis, C. pauciflora, C. sterilis, C. castanea, C. Buxbaumii, etc.5. Cold-temperate species at their northernmost limit: C. arctata, C. Crawfordii, C. Deweyana, C. eburnea, C. intumescens var. Fernaldii, C. leptonervia, C. pedunculata, C. retrorsa, C. scoparia, C. tribuloides, C. viridula, C. vulpinoidea, etc.A line drawn from Anticosti island to Lake Mistassini and James Bay seems to constitute an important natural limit for many species in the flora of Quebec.6. Halophytic species: C. hormathodes, C. Lyngbyei, C. Mackenziei, C. nigra, C. paleacea, C. recta. C. Lyngbyei, a species of arctic shores, has its southernmost limit on Anticosti island.Special consideration is given to the members of the critical section EXTENSAE (the flava-group) and their numerous hybrids.The general conclusion is that Anticosti belongs to the colder part of the temperate zone, with arctic or subarctic "islands" on the river flats, on windswept cliffs, or in bogs.The author concludes with a few notes on the economical value of sedges as pasture and their relation to deer-grazing.