Fissidens colliculosus Brugg.-Nann., 2025

Bruggeman-Nannenga, Maria Alida, 2025, Notes on African Fissidens, including F. colliculosus Brugg. - Nann., sp. nov., F. sciophyllus subsp. capeverdensis subsp. nov. and F. pellucidus var. ripensis comb. nov., stat. nov., Cryptogamie, Bryologie 20 (3), pp. 15-33 : 18

publication ID	https://doi.org/10.5252/cryptogamie-bryologie2025v46a3
DOI	https://doi.org/10.5281/zenodo.16419107
persistent identifier	https://treatment.plazi.org/id/03A3AD0F-FF82-FFE3-A0A0-FD7CFB72FCDA
treatment provided by	Plazi
scientific name	Fissidens colliculosus Brugg.-Nann.
status	sp. nov.

Treatment

Fissidens colliculosus Brugg.-Nann. , sp. nov.

( Fig. 1 View FIG )

HOLOTYPE.— Madagascar • Tsimbazaza ; on soil; 3.VI.1976; P.Tixier 8027 ; Holotype: MNHN [ PC0786650 ] (mixed with F. rosulatus P. de la Varde ) .

DIAGNOSIS. — This new species is characterized by the completely limbate vaginant laminae on all leaves, the limbidia frequently extending onto the apical lamina; the laminal cells tiny, smooth, convex; the costae excurrent; and axillary antheridial buds frequent. Fissidens colliculosus Brugg.-Nann. , sp. nov., is most likely to be confused with other semilimbate species with convex or mammillose cells. Of these, F. submarginatus Bruch in Krauss differs in its highly and sharply mammillose cells, and F. subundatus Dury in its convex cells each with a small papilla (those of the new species are convex and smooth), and its corticolous habitat. Fissidens reflexus Hampe and F. subscleromitrius Bizot & Dury have shorter limbidia.

ETYMOLOGY. — The occurrence of small, convex, smooth cells is remarkable in a subgen. Polypodiopsis species that typically have pluripapillose, mammillose or smooth, ± plane cells. The species is named for these convex cells that produce a somewhat colliculose (collis: hill; -osus: rich in) leaf surface.

DESCRIPTION

Stem with central strand, unbranched to heavily branched, not heterocaulous, pinnately foliated, 5-11 × 1-2 mm, rhizoids brown, smooth; axillary nodules not differentiated; leaves distant to close, up to 16 pairs, crispate when dry, soft, lanceolate to elliptic-lanceolate with an acute, acuminatemucronate apex, 1.0-1.5 × 0.3-0.4 mm, 3-4.5 times as long as wide, margin subentire where elimbate; limbidia on the vaginant laminae of all leaves, extending the complete length of the vaginant lamina, frequently extending onto the apical lamina, confluent at the apex of the vaginant lamina or not, up to 16 µm wide, marginal, unistratose; vaginant lamina 2/3- 3/4 the leaf length, subequal, near the insertion about as wide as the stem, unistratose; dorsal lamina variable below, often rounded, plane, less often undulate, reaching the insertion, rarely decurrent; dorsal and apical lamina unistratose, unito bistratose near the costa; costa excurrent, bryoides-type; lumina mid dorsal laminal cells 3.5-6.5 × 2.5-5.5 µm, walls thin, up to 1 µm diam., convex, smooth; lumina mid vaginant laminal cells 4.5-7.0 × 2.5-5.5 µm, walls up to 1 µm diam., convex, smooth. Gemmae not seen.

Perichaetia and perigonia on the same or on different stems, perigonia terminal on stems and branches; perigonial branches bud like and short, ± 0.5 mm long (stalk included) ( Fig. 1D View FIG ) to branch like and to up to 0.9 mm long, antheridia 170-200 µm long; perichaetia terminal, perichaetial leaves 1.3-1.9 mm long, archegonia 250 µm long; calyptra smooth, 0.6 mm long. Sporophyte, seta 4 mm long, smooth, 1 per perichaetium; theca erect, cylindric, 0.8-1.0 × 0.3 mm, ± 32 columns of oblong exothecial cells; peristome-type unknown, tooth base 48.5 µm wide; operculum rostrate, 0.4 mm long; spores not observed.

The semilimbate leaves and the low number of columns of exothecial cells indicate that the new species belongs to subgenus Polypodiopsis (Müll.Hal.) Broth. This subgenus is characterized by c. 32 columns of exothecial cells and probably scariosus-type peristomes. However, since the peristome teeth of F. colliculosus Brugg.-Nann. , sp. nov., are broken the type cannot be determined with certainty.