Himantormia deusta
Himantormia deusta (Hook. f.) A. Thell & Søchting
Bibliotheca Lichenologica 95: 537. 2007.
Basionym: Parmelia enteromorpha var. deusta Hook. f., Flora Antarctica (Bot. Antarc. Voyage Erebus and Terror. 1): 532. 1847.—Hypogymnia deusta (Hook. f.) C. W. Dodge, Trans. Amer. Microscop. Soc. 84: 506. 1965.—Cetraria deusta (Hook. f.) Imshaug, in sched. —Nimisia deusta (Hook. f.) Fryday, Lichenologist 37: 315. 2005.
Synonym: Nimisia fuegiae Kärnefelt & A. Thell, Lichenologist 25: 370. 1993.
Description (adapted from Kärnefelt & Thell 1993).
Thallus fruticose, dichotomously to irregularly branched, forming small patches over open rock, 1-2 cm diam. Lobes rather short, caniculate, 0.5(-1) cm high, c. 0.5-1 mm broad, arising from rudimenatry squamulous basal portions, upper surface pale brown to dark, lower surface black, both surfaces with numerous small wrinkles and ridges. Thallus in section c. 150-400 µm thick, differentiated in unique anatomical layers. Cortex composed of 1-3 layers, c. 20-30 µm thick, of strongly pigmented extremely large, rather uniform cells, c.10-15 µm diam. Medulla composed of periclinally arranged, rather dense, strongly gelatinized hyphae, c. 7-9 µm thick.
Apothecia sessile, up to 1.5 mm diam., with blackish disc and thalline margin, developed laminally on the upper surface of the lobes, sometimes assuming a terminal position on the lobes when mature. Thalline margin prominent. Exciple cupular, 2-layered, the upper layer composed of gelatinized hyphae, c. 50-60 µm thick, the lower layer less gelatinized, paraplectenchymatous, c. 40-50 µm thick. Hymenium c. 40-60 µm high. Asci clavate c. 45 x 15 µm, tholus with a broad, short ocular chamber and large axial body c. 4-5 µm broad. Ascospores simple, ellipsoid, colourless, c. 8-9 x 5 µm. Paraphyses septate, c. 1-2 µm thick, thickened at tips. Conidiomata pycnidia, immersed in thallus. Conidia oblong, citriform, c. 8-10 x 1.5 µm.
Conidiomata pycnidia, immersed in thallus. Conidia oblong, citriform, c. 8-10 x 1.5 µm.
Chemistry: thallus K–, C–, KC–, P+ orange-red, UV–; fumarprotocetraric acid by TLC.
Distribution and Ecology:
Known only from the southern tip of South America and the Falkland Islands where it grows directly attached to rocks.
Notes:
Collections from the Falkland Islands differ from those from Fuegia in having a much more robust thallus with convex lobes. However, these are intermixed with typical forms, and because all have the same characteristic cortex composed of large (to 20 µm) cells, as well as a uniform chemistry and identical apothecial anatomy, I have no hesitation in including them in H. deusta.