Myriocoleopsis minutissima subsp. myriocarpa (Nees & Mont.) R.L.Zhu, Y.Yu & Pócs 2014

Yu, Ying, Pócs, Tamás & Zhu, Rui-Liang, 2014, Notes on Early Land Plants Today. 62. A synopsis of Myriocoleopsis (Lejeuneaceae, Marchantiophyta) with special reference to transfer of Cololejeunea minutissima to Myriocoleopsis, Phytotaxa 183 (4), pp. 293-297 : 294-295

Myriocoleopsis minutissima subsp. myriocarpa (Nees & Mont.) R.L.Zhu, Y.Yu & Pócs , comb. nov.

Basionym: — Lejeunea myriocarpa Nees & Mont. in Ramon de la Sagra, Hist. Fis. Pol. Y Natur. Cuba 9: 473, 1842 ( Montagne 1842)

Type: Lectotype [designated by Reiner-Drehwald (1995)]: — CUBA. “in corticibus et Lichenibus frondosis repens prope S. Marcos” ( PC).

≡ Cololejeunea myriocarpa (Nees & Mont.) A.Evans., Bull. Torrey Bot. Club 38: 256, 1911 ( Evans 1911) ≡ Cololejeunea minutissima subsp. myriocarpa (Nees & Mont.) R.M.Schust., J. Elisha Mitchell Sci. Soc. 71: 232, 1955 ( Schuster 1955)

= Physocolea myriantha Herzog, Memoranda Soc. Fauna Fl. Fenn. 27: 102, 1952 ( Herzog 1952) ≡ Cololejeunea myriantha (Herzog) S.Arnell, Bot. Notiser. 106: 164, 1963 ( Arnell 1963) ≡ Cololejeunea minutissima subsp. myriantha (Herzog) R.M.Schust., J. Elisha Mitchell Sci. Soc. 71: 232, 1955 ( Schuster 1955). Type: — SOUTH AFRICA. Cape:. Tafelberg, 600−900 m, 16 April 1922, L. Rolfes s.n. (holotype: JE).

For further synonyms, see Schuster (1980), Miller et al. (1983), Reiner-Drehwald (1994) and Pócs et al. (2014).

Illustrations (selective): — Herzog (1952 as Physocolea myriantha , p. 103, fig. 47), Schuster (1980 as Cololejeunea minutissima subsp. myriocarpa , p. 1248, fig. 757), Reiner-Drehwald (1994, p. 81, fig. 1 as Cololejeunea minutissima ssp. myriocarpa ).

Range: — pantropical.

Representative specimens examined: — AUSTRALIA. Northern Territory, Coastal Plain, Fogg Dam Conservation Reserve , 52 km ESE of Darwin, 12°30’N, 131°17’E, on twigs, 10 m, 16 May 2001, S. & T . Pócs 01035/ C ( EGR). BRAZIL. State of Rio de Janeiro, Mun. Novo Friburgo , ca. 10 km NE of town, on branches of small trees along road, 800 m, 23 July 1996, S. R . Gradstein 9800 ( GEOT). DOMINICAN REPUBLIC. Independenica , ca. 18°15′N, 71°34′W, 1987, W . Buck 14475 ( NY). KENYA. South foothills of Aberdare (Nyandarua) Mts. , along Kijabe-Thika road, on branches, fallen from canopy, 2400 m, 27 January 2003, M. S . Chuah , T . Pócs & Nairobi University students 03002/ R ( EGR). RÉUNION ISLAND. Ravine Divon on the W slope of Piton Maido , 21°03’47’’S, 55°21’59’’E, or rocky cliff, 1740–1750 m, 17 September 2008, T . Pócs 08070/ G ( EGR); Cap Méchant on the S coast, near Basse Vallée , 21°22’26.1’’S, 55°42’41.3’’E, on Pandanus stem, 8 September 2008, T . Pócs 08057/ A ( EGR). SINGAPORE. Sungei Buloh Nature Park, Mature mangrove forest, “back mangrove”, on tree branch, 11 Nov. 1998, A . Juslén 625 ( SINU). U.S.A. Florida, Jackson County, Black Spring , swamp forest, 1988, W . Buck 16660 ( NY) .

Notes:—With the present transfer, Myriocoleopsis is recognized by the combination of a set of morphological characters:1) absence of underleaves, 2) copious branching in ramicolous conditions with horizontal “rhizomes” and upright branches, 3) thin-walled and smooth leaf cells, 4) ovate to oblong leaf lobules usually strongly reduced or to a flat fold along the dorsal margin of the leaf, without a real keel, 5) crenulate leaf margin, 6) stem in transverse section with 5−30 cortical cells, and 7) gynoecial innovations repeatedly floriferous with very abundant, inflated perianths sometimes with an elongated neck.

At present Myriocoleopsis comprises four known species and one subspecies, which can be keyed out in the following key *.

1. Rhizome-like shoot usually present, leaf margin entire to slightly crenulate; male bracts usually 6−30 pairs; usually rheophytic..2

1. Rhizome-like shoot absent; leaf margin crenulate; male bracts 2−8 pairs; epiphytic ........................................................................4

2. Creeping stem with 5 cortical cells; known from Argentina, Brazil and Ecuador..................................................... M. gymnocolea

2. Creeping stem with over 8 cortical cells ............................................................................................................................................3

3. Creeping stem with 8−12 cortical cells; leaf loblues ussually distinct; known from Vietnam................................. M. vuquangensis

3. Creeping stem with 10−20 cortical cells; leaf loblues ussually indistinct; known from Brazil...................................... M. fluviatilis

4. Leaf lobules absent or strongly reduced....................................................................................... M. minutissima subsp. myriocarpa

4. Leaf lobules mostly well developed............................................................................................. M. minutissima subsp. minutissima

* Cololejeunea conchifolia ( Gottsche 1864: 163) Gradstein ( Gradstein & Hekking 1979: 109), C. dauphinii Zhu (2006: 277) , C. disciflora Tixier (1979: 604) , C. minutissima subsp. utriculifera Vanden Berghen (1961: 55) , and C. chuahiana Pócs (2002: 11) , are all poorly known species, and may belong to Myriocoleopsis ( Pócs et al. 2014) . The exact status of these taxa is unclear owing to the lack of molecular data.