Rhaphidostichum piliferum (Broth.) Broth.

Thouvenot, Louis & Müller, Frank, 2021, Contribution to the bryophyte flora of New Caledonia IV. Species new to the country, new localities together with taxonomic notes, Cryptogamie, Bryologie 20 (13), pp. 181-196 : 194

* Rhaphidostichum piliferum (Broth.) Broth.

SPECIMEN EXAMINED. — New Caledonia. North Province, Hienghène, Pwé Hwa Wéc river, 20°38’23”S, 164°52’10”E, on rocks of creek bank in rain forest, metamorphic bedrocks, 630 m, 22.IX.2019, Thouvenot NC2774 PC[(PC0712111)].

COMMENTS

The genus Rhaphidostichum M.Fleisch. is reported first from New Caledonia. It is characterized by smooth leaf cells, ecostate and concave leaves, abruptly narrowed in piliform acumens, with inflated alar cells of Acroporium - type ( Tan et al. 2011). Among the species present in South Asian and Malesian regions, R. piliferum is a robust plant, with branches 20-40 mm long, leaves erecto-patent to spreading both in dry and wet conditions, margins entire throughout. R. loriforme (Broth. & Geheeb) Broth. is distinguished mainly by margins serrulate in upper part including the acumen and a slender habit. Although the New Caledonian specimen ( Fig. 6 ) exhibits smaller leaf size and relatively shorter acumen, we take it

as a small form of R. piliferum with whom it shares branches 3-4 mm broad with leaves, leaf margins entire, rarely minutely serrulate at leaf shoulders, shining yellowish-green colour. The specimen is sterile and was growing on rocks mixed with Ectropothecium sodale (Sull.) Mitt. , Heteroscyphus deplanchei (Steph.) Schiffn. , Zoopsis setulosa Leitg. , Podomitrium marginatum (Steph.) Hürl. The new locality extends to the south the range of this species previously known from South Asia and Solomon Islands ( Tan et al. 2011).

Figures

FIG. 6. — Rhaphidostichum piliferum (Broth.) Broth: A, leaf alar cells; B, leaf acumen; C, D, leaves. From Thouvenot NC2774. Scale bars: A, 20 µm; B, 100 µm; C, D, 500 µm.