Chionoloma tenuirostre var. tenuirostre M. Alonso, M. J. Cano & J. A. Jiménez var. tenuirostre

* Chionoloma tenuirostre (Hook. & Taylor) M.Alonso, M.J.Cano & J.A.Jiménez var. tenuirostre

SPECIMENS EXAMINED. — New Caledonia. North Province, Poya 15 km NE, limestone massif Roche d’Adio, 21°14’S, 165°15’E, on limestone rockface, c. 200-250 m, 06.IX.2003, Müller NC464 (DR).

COMMENTS

In New Caledonia, three species of the genus Chionoloma Dixon were hitherto known, namely Chionoloma dubium (Thér.) M.Alonso, M.J.Cano & J.A.Jiménez, C. orthodontum (Müll.Hal.) M.Alonso, M.J.Cano & J.A.Jiménez, and C. schlimii (Müll.Hal.) M.Alonso, M.J.Cano & J.A.Jiménez (Alonso et al. 2019). Record details of our own collections of

C. dubium and C. schlimii (as C. crassicostatum (D.H.Norris & T.J.Kop.) M.Alonso, M.J.Cano & J.A.Jiménez) are given in Thouvenot et al. (2018). Here we report a fourth species of the genus, C. tenuirostre, as new for New Caledonia. This species is most similar to C. orthodontum, but is differing by its leaf basal marginal cells, which do not extend up the margin to form a V-shaped pattern, and its dorsal stereid band of the costa, which is usually larger than the ventral band (Alonso et al. 2019). Chionoloma tenuirostre var. tenuirostre has a cosmopolitan distribution, except for arctic regions (Alonso et al. 2019), the nearest known records are in Australia, New Zealand and Papua New Guinea.