Dolichomitriopsis cherdantsevae Ignatov & Ignatova, 2019

Ignatova, E. A., Fedosov, V. E., Fedorova, A. V., Spirina, U. N. & Ignatov, M. S., 2019, On moss family Lembophyllaceae in the Russian Far East, Arctoa 28 (2), pp. 179-202 : 194-197

Dolichomitriopsis cherdantsevae Ignatov & Ignatova , sp. nov.

Type: Russia, Primorsky Territory, Livadijskaya (Pidan) Mt., left tributary of Pryamoj Klyuch , 43°06’N, 132°41’E, alt. 450 m, on rocks in forest, 28.VIII. 2007, Ignatov 07-160. Holotype MW9037078 , isotypes MHA9109603 , LE.

Diagnosis. Differs from Dolichomitriopsis diversiformis in loose vs. dense tufts; secondary stems longer, to 10 cm vs. 3–4 cm long, subpinnate vs. dendroid branching; secondary stem and branch leaves erect-spreading vs. imbricate when dry; secondary stem and branch leaves not variable in shape, widest at 1/4–1/2 the leaf length vs. variable in shape, widest at 1/3– 2/3 the leaf length; and attenuate flagelliform branches present vs. absent.

Etymology. The species name is given in honor of Valentina Yakovlevna Cherdantseva (1939–2013), Russian bryologist who worked in Vladivostok and made a great impact into the knowledge of the moss flora of Primorsky Territory.

Plants slender, pale-green, slightly glossy, forming loose tufts. Secondary stems erect to ascending, to 10 cm long, irregularly to subpinnately branched; stipe short or absent; attenuate-flagelliform branches often present. Secondary stem leaves erect-spreading when dry and wet, 1.5–1.8× 0.5–0.6 mm, ovate-lanceolate, acuminate, slightly concave in lower half; costa single, gradually narrow-

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ing, occasionally forked, extending to 1/2–3/4 the leaf length; margins plane, serrulate in upper 1/2, weakly serrulate almost to the base; upper and median laminal cells linear, 40–80×7–8 µm, thick-walled, eporose or weakly porose; basal laminal cells long rectangular, 40– 70×7–9 µm, thick-walled, weakly porose; alar group well delimited, consisting of isodiametric, irregular in shape, thick-walled, dark colored cells. Branch leaves similar to secondary stem leaves but smaller.

Dioicous. Perichaetia numerous on secondary stems. Perichaetial leaves from oblong sheathing base narrowed into long triangular acumen, acumina spreading. Male plants and sporophytes not seen.

Distribution and ecology. This species is endemic for the Russian Far East. It was collected several times at one locality, on slope of Pidan (Livadijskaya) Mt., at 450– 900 m alt., in mixed conifer & broadleaved forest, on rocks covered with mosses.

Other specimen examined: Russia, Primorsky Territory, Pidan (Livadijskaya) Mt. , 43°05’N, 132°41', 900 m alt., Ignatov & Ignatova 06-2107 ( MHA9109604 & MW9037077 ); same place, 43°06’N, 132°41’E, alt. 400-500 m, Ignatov & Ignatova 06-2397 ( MW9037075 ) .

Dolichomitriopsis diversiformis (Mitt.) Nog., J. Jap.

Bot 22: 83. 1948.

Plants medium-sized, pale-green or yellowish-green, slightly glossy, forming dense tufts. Secondary stems erect, 3.5–4 cm long, dendroid, stipe short; stoloniform branches absent. Secondary stem leaves imbricate when dry and wet, 1.2–1.3(–1.7)×0.6–0.7(–0.9) mm, ovate, oblong or obovate, widest at 1/3–2/3 the leaf length, acuminate, concave; costa single, stout, gradually narrowing, occasionally forked, extending to 1/2–5/6 the leaf length; margins plane, serrulate in upper 1/2, entire below; upper laminal cells rhomboidal to oblong-elliptical, 12–20×8–10 µm, thick-walled, eporose; median laminal cells sublinear, slightly flexuose, 20–40×5–6 µm, thick-walled, eporose; basal laminal cells long rectangular, 25–45×6–7 µm, thick-walled, eporose; alar group small to medium-sized, well-delimited, consisting of isodiametric, irregular in shape, thick-walled, dark colored cells. Branch leaves similar to secondary stem leaves but smaller.

Dioicous. Perichaetia numerous on secondary stems and branches. Perichaetial leaves from oblong sheathing base narrowed into long triangular acumen, acumina spreading. Setae straight, 7–10 mm long. Capsules erect, symmetric, oblong-cylindric, smooth, reddish-brown. Annulus consisting of small cells. Exostome teeth 250 (–300) µm long, papillose throughout; endostome basal membrane low; segments narrow, not perforated; cilia absent. Spores 14–18 µm.

Distribution and ecology. In the Russian Far East D. diversiformis is known from the South Kuril Islands and Primorsky Territory; it grows at altitudes from sea level to 695 m, in broadleaved, conifer and mixed forests, and occasionally on meadows. It was collected from tree bases (of Sorbus, Alnus, Betula, Quercus , and Abies ), as well as on rocks and rock outcrops.

Specimens examined: Russia: Sakhalinskaya Province, Island Kunashir: 5-6 km east of Golovnino , 43°45'N, 145°34'E, 18.VII.1990 Nedoluzhko s.n. ( MHA9109601 ) ; cape Mysovyj , 44°17'N, 146°17'E, 40 m alt., Ignatov 06-1847 ( MW9037073 ) ; vicinities of Tretjakovo Settlement , 43°58'N, 145°39'E, 123 m alt., Koroteeva 15-10/7-7 & 15-10/4-3 ( MHA9049327 & MHA9049325 ) ; Bay Aerodromnaya , on hill top, 43°48'N, 146°45'E, 11.IX.2006 Nyushko Sh-28-06f ( MHA 9109597 ) ; Ruruy Mt. , 44°28'N, 146°06'E, 450m alt., Ignatov 06-1125 ( MHA9109600 ) ; Island Shikotan: area of Malokurilsk Village , 43°52'N, 146°51'E, 100 m alt., Bakalin K-37-3-07 ( MHA9109598 ) ; Primorsky Territory: Vladivostok Area, near Lyanchikhe Settl. , 26.IX.1950 Voroshilov s.n. ( MHA9109605 ) ; Lazo Distr., Elomovsky Creek , 43°14'N, 133°43'E, 695 m alt., Ignatov & Ignatova 13-1742 ( MHA9109599 ) .

Differentiation. Differences between D. diversiformis and D. cherdantsevae are given in the diagnosis of the latter species. Isotheciastrum subdiversiforme has leaves of similar shape; however, in that species leaves are erect-spreading vs. imbricate in D. diversiformis , with sharply serrate vs. serrulate margins; furthermore, if sporophytes are present, these species are easily recognized due to asymmetric, inclined vs. symmetric, erect capsules.