640803 Dryas punctata Juz.
- Juz., Izv. Glavn. Bot. Sada SSSR 28: 320 (1929). Type (LE): Siberia: the Lake Baikal area, "prope Ircutiam", leg. Stubendorff. - Dryas octopetala subsp. punctata (Juz.) Hultén, Acta Univ. Lund., n. s., sect. 2, 42, 1: 1047 (1946).
Geography: European (NE) - Asian (N/C) - amphi-Beringian - Cordilleran.
Notes: Elven and Murray: Dryas punctata is characterized by punctiform colourless glands on the upper leaf surface (making it sticky), stipitate red glands along the lower leaf surface midvein, and absence of feathery hairs. We accept this species in a more restricted sense than done by Yurtsev (1997). We find northern Siberian and Chukotkan D. punctata (s. str.) to be a recognizable taxon (i.e., we differ from Hultén's opinion), but if all stray plants with some punctate glands (often combined with feathery hairs) in other areas are included, D. punctata looses its integrity.
Yurtsev (PAF proposal) accepted three races: the mainly Asian subsp. punctata (by him as Eurasian and with extension into Alaska), the northwestern North American subsp. alaskensis with a slight extension into northeastern Asia (the Chukchi Peninsula), and the Cordilleran plant treated by Yurtsev as subsp. hookeriana but assumed by him not to reach the Arctic. The North American patterns of subsp. alaskensis and subsp. hookeriana are typical of plants isolated and diverging north and south of the Pleistocene Cordilleran and Laurentide Ice Sheets and subsequently migrating into the deglaciated areas. Comparing D. punctata s. str. and subsp. alaskensis in East Chukotka, where they meet but in different site types and where intermediates are not very frequent, Elven and Solstad in 2005 found them different.
Some support for our observations is found in the molecular data (Skrede et al. 2006). The AFLP markers assigned D. punctata (s. str.) from northern Yakutia to a different main group from subsp. alaskensis from Alaska and the Yukon Territory. No samples of Chukotkan D. punctata was included in the AFLP study. Within each of these main groups, the 'punctate' plants were more similar in markers to their feathery-haired partners in the same area, and in the North American group also to D. integrifolia. There is therefore discordance between morphological and molecular data but the molecular data from northeastern Asia and northwestern North America are very restricted. We suspect that D. punctata subsp. punctata and subsp. alaskensis may be less closely related than assumed by Yurtsev (i.e., they may be different species). Neither are we convinced that D. punctata s. str. occurs west of the Urals or on the American side. We will, however not propose a formal change from Yurtsev's proposal before more molecular evidence is available and before the morphological variation is analysed more thoroughly.
Higher Taxa
- Dryas [6408,genus]