Didymodon calciphilus Ignatova & Ignatov, 2024

Ignatova, E. A., Fedosov, V. E., Kuznetsova, O. I., Fedorova, A. V. & Ignatov, M. S., 2024, On the genus Didymodon s. str. (Pottiaceae, Bryophyta) in Russia, Arctoa 33 (2), pp. 129-155 : 151-152

publication ID

https://doi.org/10.15298/arctoa.33.14

persistent identifier

https://treatment.plazi.org/id/03FADB22-FFD9-9D01-335C-FADDFD4AFB23

treatment provided by

Felipe

scientific name

Didymodon calciphilus Ignatova & Ignatov
status

 

10. Didymodon calciphilus Ignatova & Ignatov , species nova. Fig. 16 View Fig .

Type: Russian Far East, Primorsky Territory , Partizansk District , Lozovyj (Chandolaz) Range , 43°00’N, 133°00’, 360 m alt., foothills, rock outcrops in oak forest, 26 August 2007 Ignatov 07-83 (holotype MHA9108971 About MHA , isotype MW9036162 ) .

Etymology: species name refers to its substrate preferences.

Plants medium-sized to large, in dense tufts, rigid, green or dark-green, dull but with shiny costae. Stems to 3 cm long, erect or ascending, simple or repeatedly branched, without hyalodermis, with large central strand. Rhizoidal tubers absent. Leaves slightly flexuose and incurved when dry, erectopatent in distal part of stem, below with appressed bases and widely spreading acumina when wet, from ovate, scarcely differentiated bases gradually or +abruptly narrowed into triangular acumina 1.5– 2 times longer than bases, acute, not or short decurrent, (1.3–)1.5–1.9×(0.3–) 0.5–0.55 mm, widely keeled or almost flat distally; margins narrowly recurved in proximal 1/2–4/5, unistratose, entire; costa 65–75 µm wide at leaf base, gradually narrowing upwards, percurrent, strongly prominent dorsally, flat ventrally, on both surfaces with quadrate, smooth cells, without band of translucent cells on ventral side below apex, in transverse sections semicircular, with 3–5 guide cells in 1 layer, ventral stereids in 1(2) layers, ventral epidermis differentiated, with outer walls not bulging, dorsal stereids in 1–3 layers, dorsal epidermis differentiated; lamina unistratose; upper and median laminal cells rounded-quadrate, elliptic and transversely elliptic, 5–8×4–7 µm, thick-walled, on both surfaces with low, simple or bifid papillae; basal juxtacostal cells rectangular, 12–20×7–9(–11) µm, smooth, with moderately thickened, straight walls; basal marginal cells quadrate. KOH-reaction yellowish-green. Asexual reproduction by ovate and round multicellular gemmae on branched stalks in leaf axils. Gametangia and sporophytes unknown.

This species is currently known from Lozovyj Range in Primorsky Territory and from Gunib District in Dagestan. It grows on dry calcareous rocks. It can be recognized by combination of rigid, dark-green plants, leaves usually gradually tapered from ovate base into triangular acumina, narrowly recurved margins, papillose laminal cells, and ovate, multicellular gemmae. It differs from D. cordatus in different leaf shape, with scarcely differentiat- ed bases and recurved but not strongly revolute leaf margins. From D. baicalensis it can be separated by costa with one layer of guide cells and ventral stereids present.

Kingdom

Plantae

Phylum

Bryophyta

Class

Bryopsida

Order

Pottiales

Family

Pottiaceae

Genus

Didymodon

Darwin Core Archive (for parent article) View in SIBiLS Plain XML RDF