Micranthes stellaris (Saxifragaceae), new to Québec

Abstract

Micranthes stellaris (L.) Gornall (— Saxifraga stellaris L.) is a perennial arctic-alpine amphi-atlantic species (Hulten and Fries 1986). Closely related to the circumpolar M. foliolosa (R. Br.) Gornall (= S. foliolosa R. Br.; S. stellaris var. comosa Poir.), it is easily distinguished by the hairy adaxial surface of the leaves and by the absence of bulblets in the inflorescence. Viviparous plants are known to occur sporadically in Europe (Webb 1993) but have not yet been observed in North America (Bocher et al. 1968; Porsild 1920; M. Blondeau, qfa, pers. comm.). The geographical range of Micranthes stellaris extends from mountainous areas of eastern Europe westward to Iceland, Greenland, Labrador, and Baffin Island (Scoggan 1978; Webb 1993). Porsild (1964) and McJannet et al. (1993) based the Baffin Island report of the species on a single collection made on Kekerten Island (Cumberland Sound) by James Taylor, who served on whaling vessels in the Davis Strait between 1856 and 1861 (Taylor 1862). Arguing that the east coast of Baffin Island has been relatively well collected and that this single collection was not enough to support its occurrence in the Canadian Arctic Archipelago, Aiken et al. (1998) proposed to treat the species as an excluded taxon at this time. The original voucher could not be located in the Kew Herbarium, having been lost or mislaid (S. Landrein, K, pers. comm.). Fortunately, a photograph of the voucher, taken and annotated by Porsild in 1962, is held at the National Herbarium of Canada (can 272374, negative J8166-30). The plant shown is definitely M. stellaris, exhibiting the typical habit of the plant, the lax panicle with divergent branches, and the complete absence of bulblets in the inflorescence. Therefore, the species should be maintained in Baffin Island's flora.