Kiaeria pumila (Mitt.) Ochyra, 1993

Ivanets, Viktoria, Wierzgoń, Mariusz, Yevchun, Hanna & Parnikoza, Ivan, 2023, Range extensions for moss species on the west side of the Antarctic Peninsula, Cryptogamie, Bryologie 20 (2), pp. 61-88 : 66

Kiaeria pumila (Mitt.) Ochyra

SPECIMENS EXAMINED. — Antarctica. West Antarctic Peninsula, Graham Coast , Wilhelm Archipelago, in the north-eastern part of Hovgaard Island , 65°07’15”S, 64°04’07”W, alt. 30 m a.s.l., on rock surface above the moss bank, 20.II.2019, Ivanets 52a/19 ( KRAM [B-260628]); Ivanets 52b/19 ([ B-260629 ]); same area, in the lower part of the exposed rocky buttress in the company of bryophyte species growing in the immediate vicinity, including Polytrichastrum alpinum , Sanionia georgicouncinata , Andreaea regularis , Pohlia nutans and Barbilophozia hatcheri , 12.II.2022, Parnikoza 13/22 ( KRAM [ B-262838 ]); same island, 65°07’14”S, 64°04’08”W, alt. 30 m a.s.l., at the base of the exposed rocky buttress together with Pohlia nutans and Lophozia excisa (Dicks.) Dumort. growing in the close proximity, 12.II.2022, Parnikoza 07/22 ( KRAM [ B-262844 ]); same island, 65°07’14”S, 64°04’05”W, alt. 30 m a.s.l., on exposed rock surface above the moss bank associated with Andreaea regularis , Hymenoloma crispulum and Bucklandiella sudetica , 12.II.2022, Parnikoza 04/22 ( KRAM [ B-262848 ]).

REMARKS

On Hovgaard Island Kiaeria pumila was found at three sites close to each other in the vegetated north-facing oasis covered mainly by Polytrichum strictum Brid. moss bank in the north-eastern part of this island. Some were collected from rock outcrop surfaces inclined near 40° in lower, wetter and shadowed parts, in association with Andreaea regularis and Sanionia georgicouncinata . In higher, more exposed and sunny parts Hymenoloma crispulum and Bucklandiella sudetica also occur. Sometimes cushions of K. pumila occur on moss carpets dominated by Brachythecium austrosalebrosum (Müll. Hall) Kindb. , Pohlia nutans and Sanionia georgicouncinata and together with Lophozia excisa and Barbilophozia hatcheri , situated in depressions between stands of a moss bank of Polytrichum strictum Menzies ex Brid. and Chorisodontium aciphyllum (Hook.f. & Wilson) Broth. with small turves of Pohlia nutans and Polytrichastrum alpinum .

Although Kiaeria pumila is a species which is immediately distinct from other Antarctic taxa of dicranalean mosses, it is very likely that it is actually a complex of two closely related species. Unfortunately, almost all Antarctic populations are sterile and fully mature sporophytes have only been found in two specimens from Rasmussen Island on the Graham Coast and sporophyte traits are of critical taxonomic importance in this genus. Antarctic plants of this species represent two distinct morphological types. Mosses belonging to one group have a typical dicranoid aspect with regular strongly falcatosecund leaves, which are sometimes even circinate at the stem spices. In contrast, in plants belonging to the second group, the falcation of the leaves is less obvious or absent and the leaves are straight, flexuose and somewhat crisped.Microscopically these two phenotypes are almost inseparable from each other, having identical leaf areolation and prominent, often ventricose and coloured alar cells. In this situation, molecular data can be very helpful in establishing the identity of plants with different leaf shapes and DNA of Antarctic specimens of K. pumila urgently needs to be sequenced. In all sites on Hovgaard Island the plants showed a typical dicranoid aspect with regularly strongly falcato-secund leaves were collected.

In Antarctica, Kiaeria pumila is an infrequent species, although locally it may occur in abundance. It is widely distributed but scattered in the northern and central maritime Antarctic ( Fig. 3 ). It is relatively frequent in the South Orkney Islands and becomes rare and localized southwards in the South Shetland Islands and the Antarctic Peninsula. It is very rare on the Trinity Peninsula and scattered on the Danco Coast and Graham Coast on the west side of the Antarctic Peninsula. In the latter it is known only from six sites, five of which are on the offshore islands, including Hovgaard Island, Petermann Island, Rasmussen Island, Berthelot Islands and the largest island off Takaki Promontory at latitude 65°33’S (the southernmost station of K. pumila ). On the mainland Graham Coast it has been recorded only once on Cape Pérez. The species is widespread on subantarctic South Georgia ( Ochyra et al. 2002).

Figures

FIG. 3. — Distribution map for Kiaeria pumila (Mitt.) Ochyra in the Graham Coast area and in the Antarctic Peninsula region including the South Shetland Islands (inset). The new locality on Hovgaard Island is marked with a triangle.