Saturday, January 13, 2018

[Bryophyta • 2018] Sphagnum incundum • A New Species in Sphagnum subg. Acutifolia (Sphagnaceae) from Boreal and Arctic Regions of North America

Sphagnum incundum  Flatberg & Hassel

in Kyrkjeeide, Hassel, Shaw, Shaw, Temsch & Flatberg, 2018.

We describe Sphagnum incundum in Sphagnum subgenus Acutifolia (Sphagnaceae, Bryophyta). We used both molecular and morphological methods to describe the new species. Molecular relationships with closely related species were explored based on microsatellites and nuclear and plastid DNA sequences. The morphological description is based on qualitative examination of morphological characters and measurements of leaves and hyalocysts. Morphological characters are compared between closely related species. The results from Feulgen densitometry and microsatellite analysis show that S. incundum is gametophytically haploid. Molecular analyses show that it is a close relative to S. flavicomans, S. subfulvum and S. subnitens, but differs both genetically and in morphological key characters, justifying the description of Sphagnum incundum as a new species. The new peatmoss is found in North America along the western coast of Greenland, in Canada from Quebec and Northwest Territories, and Alaska (United States). The new species has a boreal to arctic distribution.

Keywords: Bryophytes, Sphagnaceae

FIGURE 8. Sphagnum incundum in field surface view.
A: The type collection including selected holotype and isotypes. Collected in Ivujivik, Quebec, Canada, in intermediate, slightly sloping arctic fen.
Photo by K. I. Flatberg, 4 July 2007. Flatberg 314-07 (TRH B-9718). 
B: Together with S. squarrosum, both with young sporophytes. From Inukjuak, Quebec, Canada, in topogenous, rich fen lawn in arctic mire.
Photo by K. I. Flatberg, 14 August 2007. Flatberg 451-07 (TRH B-9999). 

Sphagnum incundum Flatberg & Hassel sp. nov. 

 Diagnosis:— Sphagnum incundum is in macro-morphology recognized by slender shoots with predominantly brownorange to purple-red capitula and straight and non-recurved leaves on innermost capitulum branches on dry plants. In micro-morphology, it is foremost recognized by narrowly lingulate stem leaves with acute to acute-obtuse apices, strongly S-shaped stem leaf hyalocysts with common occurrence of faint fibrils in distal leaf-parts, and divergent branch leaf hyalocysts on distal end convex surfaces with pores usually occupying between 1/3 and 1/2 of cell width. The new species is gametophytic haploid and closely allied morphologically to S. flavicomans, S. subfulvum, and S. subnitens.

Etymology:— The specific epithet is derived from the Latin adjective incundus = pleasant, agreeable, delightful.

 Distribution:— West Greenland, Canada in Quebec, Nunavut and North West territories, and U.S.A in Alaska. Currently known from the northern boreal to middle arctic vegetation zone. 

Ecology:— Sphagnum incundum in arctic localities in West Greenland, and Nunavik, Quebec, occurs in arctic mires on shallow peat in intermediate and rich fens, partly forming small mats and low cushions on gently sloping, soligenous mire, partly growing in small patches on lawn and carpet mire. The most commonly associated sphagna in both regions were S. concinnum (Berggr.) Flatberg (2007: 88), S. squarrosum, S. teres and S. warnstorfii Russow (1886: 315). In the boreal Anchorage area, Alaska, it was found growing in a large fen mire on high lawn patches in topogenous, varyingly intermediate to rich fen vegetation, associated with S. papillosum Lind. (1872: 280), S. subfulvum and S. miyabeanum Warnstorf (1911: 321). In Bethel area, Alaska, it occurred scattered on intermediate fen lawns in tundra mire.

 Magni Olsen Kyrkjeeide, Kristian Hassel, Blanca Shaw, A. Jonathan Shaw, Eva M. Temsch and Kjell Ivar Flatberg. 2018. Sphagnum incundum A New Species in Sphagnum subg. Acutifolia (Sphagnaceae) from Boreal and Arctic Regions of North America. Phytotaxa. 333(1); 1–21. DOI:  10.11646/phytotaxa.333.1.1