Crossocalyx hellerianus (Nees ex Lindenb.) Meyl.

Unan, Ayşe Dilek & Ören, Muhammet, 2021, New and noteworthy records of deadwood dwelling bryophyte species for Turkey and Southwest Asia, Cryptogamie, Bryologie 20 (4), pp. 33-44 : 35-36

2. Crossocalyx hellerianus (Nees ex Lindenb.) Meyl.

( Fig. 3 )

Bulletin de la Société vaudoise des Sciences naturelles 60: 266 (1939). — Anastrophyllum hellerianum (Nees ex Lindenb.) R.M.Schust. , American Midland Naturalist 42: 575 (1949).

SPECIMEN EXAMINED. — Turkey. Sinop province, Durağan district, around Çandağı village, 41°28’26”N, 035°19’03”E, on decayed Abies nordmanniana subsp. equitrojani log, 1163 m. a.s.l., 24.VII.15, Ören 525/15, ZNG.

ECOLOGY. — Crossocalyx hellerianus is acidophyte, hygrophyte-mesophyte, and sciophyte-photophye (Dierssen 2001). This saprolign species mainly colonizes on decorticated woody debris ( Smith 1996; Dierssen 2001; Casas et al. 2009), and sometimes on bark ( Paton 1999; Frey et al. 2006). Sporophytes of C. hellerianus are not common, and reproduction of this species is often achieved by gemmae, therefore C. hellerianus has a short dispersal range ( Pohjamo et al. 2006; Hultby 2011). This species is one of the indicators of old boreal forests with continuous cycle of coarse woody material ( Nitare 2000; Hultby 2011; Borovichev et al. 2017).

Turkish Crossocalyx hellerianus was found on Abies nordmanniana subsp. equitrojani log in a pure forest of Trojan fir, which is endemic for Turkey and is distributed in Northern Anatolia. The log was decayed to stage 3 according to Ódor & Van Hees (2004), moist, and approximately 45 × 260 cm in dimensions. 30% of the visible surface of the log was covered with the following bryophytes (in alphabetical order): Buxbaumia viridis , Dicranum tauricum Sapjegin , Hypnum cupressiforme Hedw. var. cupressiforme , Lepidozia reptans (L.) Dumort., Lophocolea heterophylla (Schrad.) Dumort. , Nowellia curvifolia (Dicks.) Mitt. and Ptilidium pulcherrimum (Weber) Vain.

DISTRIBUTION. — Crossocalyx hellerianus has a wide European distribution ( Hodgetts & Lockhart 2020). This species has also been recorded from the Americas ( Canada, Colombia, Mexico, and United States) and Asia ( Bhutan, China, and Japan) ( Schuster 1969; Schill & Long 2002; Frey et al. 2006; Alba 2011). The Turkish record is near the southernmost Mediterranean and Western Asian distribution limit of this species.

CONSERVATION. — Despite its wide European distribution, Crossocalyx hellerianus is rare in the Mediterranean basin (Dragićevic et al. 2017), and this species classified in various IUCN categories (NT in Sweden; VU in Finland, Luxemburg, and Slovakia; EN in Czech Republic, Germany, Poland, Romania, and Switzerland; CR in Andorra, Hungary, Italy, and Spain), is also regionally extinct in Northern Ireland ( Hodgetts & Lockhart 2020). It’s shown that populations of this species are declining rapidly due to silviculture processes in Finland ( Pohjamo & Laaka-Lindberg 2003).

Turkish Crossocalyx hellerianus was found in one log in the study area. Also this species has a limited dispersal capacity and strict habitat selection. Taking into consideration these facts, it’s understood that the area of occupancy (AOO) of this species is less than 10 km 2. Hence, Turkish conservation status of this species should be assigned as “CR” according to the IUCN Criteria B2a ( IUCN 2019).

DESCRIPTION

Plants

Minute, green; sterile shoots prostrate to ascending; gemmiferous shoots erect; up to 6 mm long and 0.25 mm wide.

Leaves

Transversely inserted, mainly suberect, concave, bilobed to ⅓, lobes equal to sub-equal, apices of lobes acute, apices of gemmiferous leaves eroded, 0.2-0.3 mm long and 0.17- 0.20 mm wide. Leaf cells ±isodiametric, (14)16-20(22) µm in diameter at the middle; cuticle smooth. Oil bodies 2-4 per cell, spherical, 2-4 µm in diameter.

Gemmae

Abundant, clustered on gemmiferous shoot tips, purplish-red when mature, angular, 1-celled, ± isodiametric, 11-14 µm long and 10-13 µm wide.

Perianths and sporophytes

Not recorded in the studied specimen.

Figures

FIG. 3. — Crossocalyx hellerianus (Nees ex Lindenb.) Meyl.: A, habitus; B, shoots; C, leaf; D, median leaf cells and oil bodies; E, gemmae. Scale bars: A, 400 μm; B, 200 μm; C, 100 μm; D, E, 50 μm.