Plagiochila kiaeri Gottsche

Gradstein, S. Robbert & Reeb, Catherine, 2022, The genus Plagiochila (Dumort.) Dumort. (Marchantiophyta) in Madagascar, Cryptogamie, Bryologie 20 (5), pp. 65-106 : 82

Plagiochila kiaeri Gottsche

( Fig. 10)

Plagiochila kiaeri Gottsche, Abhandlungen des Naturwissenschaftlichen Vereins zu Bremen 7: 341 (1882). — Type: Madagascar. Borgen s.n., hb. Kiaer 1a (lecto-, designated by Grolle [1995], O).

Plagiochila ankefinensis Steph. , Bulletin de l’Herbier Boissier (sér. 2) 4 (2): 162 (1904).— Type: Madagascar ( Vanden Berghen 1981).

Plagiochila divergens Steph. , Hedwigia 30: 268 (1891). — Type: Tanzania ( Jones 1962; Grolle 1995).

Plagiochila evansii Steph. , Bulletin de l’Herbier Boissier (sér. 2) 4 (4): 354 (1904). — Type: Madagascar ( Grolle 1995).

Plagiochila imerensis Steph. , Bulletin de l’Herbier Boissier (sér. 2) 4 (6): 589 (1904).— Type: Madagascar ( Vanden Berghen 1981).

Plagiochila sparsa Steph. , Bulletin de l’Herbier Boissier (sér. 2) 4 (2): 157 (1904). — Plagiochila divergens var. sparsa [Steph.] Vanden Berghen, Bulletin du Jardin botanique national de Belgique 51: 117 (1981). — Type: Madagascar ( Vanden Berghen 1981).

SPECIMENS EXAMINED. — Madagascar. Prov. Antananarivo • Ankaratra, Manjakatompo Forest Reserve , VIII.1971, Cremers 1701 ( BR); Andramasina, Tixier 8490 ( PC). — Prov. Antsiranana • Marojejy Nat. Park , ridge N of Andampibe falls, III.1990, Pócs 90113 ( EGR). — Prov. Fianarantsoa • Ambatofitorahana 35 km S of Ambositra, I.1970, Onraedt 70 M426 , 70 M435 ( BR); VIII.1971, Onraedt 70 M5322 , 70 M5382 , 70 M5739 ( BR); near Ambositra, I.1970, Onraedt 70 M349 , 70 M349 ( BR); Ambohimahasoa region N of Fianarantsoa , I.1970, Onraedt 70 M524 , 70 M525 , 70 M557 ( BR); Andringitra Nat. Park , Pic Boby , IX.1994, Vojtkó 9458/ B ( EGR); Mt. Vohipia , Pócs 9470/ H ( EGR); Ankazonivady Forest Reserve , 16 km S of Ivato , VII.2004, Pócs et al. 04115/ A ( EGR, GOET), 04115/ AA, 04115/ Z ( EGR); Ranomafana Nat. Park , Sahamalaotra Forest , VII.2004, Pócs et al. 04120/BZ ( EGR). — Prov. Toamasina • Andasibe-Mantadia Nat. Park, Mt. Andrianavibe , X.1994, Pócs 9487/BS ( EGR) .

DISTRIBUTION AND HABITAT. — East Africa and Madagascar. In Madagascar on bark, rock and soil in subhumid mid-elevation forests, at 700-1800 m elevation.

DESCRIPTION (see also Vanden Berghen 1981

as P. divergens )

Plants 2-4 mm wide, to 6 cm long, long and slender, dichotomous in the upper part, irregularly pinnate below, branches mostly terminal, occasionally intercalary on broken stems, rhizome-like creeping shoot present. Leaves (sub)imbricate, obliquely spreading and ventrad, ± ampliate (more conspicuously ampliate towards the stem base), asymmetrically ovate-triangular, 1.3-2× longer than wide, irregularly toothed at apex and along the distal half of the ventral margin with 2-20(-25) rather small teeth, ventral leaf margin sometimes entire, apex sometimes bifid by two larger teeth, cells of the teeth short, 1-1.5(-2)× longer than wide, the tip cell of the teeth often broken, leaf margins and bases otherwise entire; dorsal leaf bases conspicuously swollen, shortly decurrent, partly concealing the stem, ventral leaf bases shortly and very narrowly decurrent, decurrent ventral part 0.1-0.2 mm long, entire. Leaf cells irregularly (sub)isodiametrical to slightly elongate, small, 12-20 µm wide in midleaf, trigones rather small, cordate or swollen, sometimes confluent, cells towards the leaf margin smaller, subrectangular, in basal stem leaves sometimes thicker-walled and forming a weak, yellowish, 1-3 cells wide border, cells towards the swollen dorsal leaf bases often conspicuously elongate, rectangular, but vitta-like region absent; cuticle smooth; oil bodies not observed. Underleaves absent. Androecia intercalary, with 4-7 pairs of bracts. Perianth without stalk, perianth mouth densely ciliate-laciniate. Vegetative reproduction not observed.

NOTES

Plagiochila kiaeri (sect. Vagae) is recognized by the irregularly pinnate to dichotomous plants with or without terminal branching, leaves ± imbricate, ventrad, ovate-triangular and less than 2× longer than wide, ventral leaf margin and apex irregularly toothed with (0-)2-20(-25) triangular teeth made up of rather short cells (tip cell of teeth often broken), and with small leaf cells, only 12-20 µm wide in midleaf and usually elongate in the dorsal leaf bases, with rather small trigones. Plagiochila kiaeri may be confused with P. incerta and P. terebrans . Plagiochila incerta differs by the horizontally spreading leaves with larger cells (20-30 µm wide in midleaf) and cells in the dorsal leaf bases not elongate. For differences with P. terebrans see the key.