Iwatsukiella W.R.Buck & H.A.Crum.

Genus Iwatsukiella W.R.Buck & H.A.Crum. View in CoL

* Iwatsukiella leucotricha (Mitt.) W.R.Buck & H.A.Crum

( Fig. 2 View FIG )

SPECIMEN EXAMINED. — Türkiye • Artvin province; Artvin, Irsa Plateau , on tree trunks ( Abies nordmanniana (Stev.) Spach. subsp. nordmanniana ); 2014 m alt.; 41°51’54.7”N, 41°15’47.7”E; 24.VIII.2022; leg. N. Batan, H. Erata, N. Batan, H. Erata, KTUB [ KTUB1626 ]; duplicate in Erata 1215 (Herb. Erata) GoogleMaps .

ECOLOGY. — Iwatsukiella leucotricha typically grows on tree trunks and fallen logs of Abies and Picea , and is occasionally on rock faces and in crevices ( Dierssen 2001). In Türkiye, the specimens were collected from tree trunks of Abies nordmanniana (Stev.) Spach. Subsp. nordmanniana on the İrsa Plateau, Karçal Mountains, in the Artvin region. DISTRIBUTION. — Iwatsukiella leucotricha is distributed across Europe (notably in the European part of Russia); Asia (including Georgia, China, and Japan); and North America (in Canada, Alaska, and Oregon) ( Ignatov et al. 2006; Hodgetts & Lockhart 2020; GBIF 2024: https://www.gbif.org/species/2681265). This record demonstrates that the Iwatsukiella leucotricha , previously known from North America and eastern Asia, has extended its distribution further within Asia, marking a new location. The majority of records for Iwatsukiella leucotricha are from Russia. In the European part of Russia, it has been documented in the Republic of Bashkortostan (Bashkiria) and the Perm Territory. In Asiatic Russia, occurrences span across numerous regions, including the Chukotka Autonomous Area, Khanty-Mansi Autonomous Area- Yugra, Republic of Sakha (Yakutia), Magadan Region, Irkutsk Region, Khabarovsk Territory, Kamchatka Territory, Commander Islands, Republic of Altai, Kemerovo Region, Republic of Buryatia, Trans-Baikal Territory, Amur Region, Primorye Territory, and Sakhalin Region (encompassing Sakhalin Island and the Kuril Islands). ( Ignatov 1994; Ignatova et al. 1995, 1996, 2013; Ignatov et al. 2001; Czernyadjeva & Potemkin 2003; Zolotov & Baisheva 2003; Bakalın et al. 2009a; b; Pisarenko 2014; Fedosov et al. 2016; Afonina et al. 2018; Pisarenko & Bakalin 2018; Dudov et al. 2018; Pisarenko et al. 2022). This new record represents the westernmost and southernmost points of Iwatsukiella leucotricha ’s global distribution. Additionally, this locality establishes it as both the southernmost occurrence of the species worldwide and the closest point to Europe within its distribution range.

DESCRIPTION

Plants small, slender 0.7-1.7 cm high, pale to yellowish-green. Stem creeping, densely pinnately branched. Brach 1-4 mm high and densely leaved. Leaves reflexed when moist and imbricate when dry. Leaves 1-2 mm tall and 0.2-1.3 mm wide, rounded or rounded ovate at base, and long, clear, hairpoint on the tip. Alar cells not clearly differentiated. Median leaf cells oblong or rhomboidal. Costa absent, or short and double.

Iwatsukiella leucotricha bears resemblance to Habrodon perpusillus (De Not.) Lindb. , yet it can be differentiated by its long, transparent hairpoint at the leaf tip and its undifferentiated alar cells. Iwatsukiella leucotricha is also morphologically close to Heterocladiella dimorpha (Brid.) Ignatov & Fedosov , from which it is distinguished by similar features: a long, clear hairpoint at the leaf tip and undifferentiated alar cells.Additionally, Heterocladiella dimorpha differs by its denticulate leaf margins and papillose cell surfaces, further setting it apart from Iwatsukiella leucotricha .

REMARKS

Iwatsukiella leucotricha was most recently assessed for the IUCN Red List of Threatened Species in 2017, where it is categorized as Least Concern (LC) ( Baisheva et al. 2019. This assessment, documented under the Europe region, is accessible in the IUCN Red List of Threatened Species (2019: e.T87468107A87758253), with data available as of March 26, 2024.