EAST AFRICAN BRYOPHYTES XXXIII. CAMPYLOPOIDEAE (LEUCOBRYACEAE, MUSCI) FROM THE INDIAN OCEAN ISLANDS

This paper contains 142 Campylopoideae records from 10 collecting trips of the author with his colleagues in the East African islands. Among the 27 taxa 15 records were new to a certain island, of which 4 were known before only from continental Africa. With these the known number of species on the Indian Ocean islands raises from 30 to 34. Observations on the ecology, distribution and illustrations of most species are also given.


INTRODUCTION
The Campylopoideae collections made in tropical East Africa by the author and his colleagues were identified and published first by Bizot (in Bizot and Pócs 1974, 1979, Bizot et al. 1977, 1978), then by Ochyra (Ochyra andPócs 1983, 1986a, b) and later by Frahm in his monograph (1985a) and in his posthumous paper (Frahm 2021).A large collection, mainly from the Indian Ocean islands of East Africa collected between 1987 and 1996, were sent also to Jan-Peter Frahm, which remained unidentified with their first specimens in EGR and duplicates were deposited after his death in the herbarium of the Botanic Garden and Botanical Museum Berlin-Dahlem (B).The author identified these and now publishes the detailed records of the less common species.From the 27 identified taxa 15 proved to be new to some of the islands and 4 of them were known before only in continental Africa.By the identification and establishing the up to date nomenclature of species the following references were used: Bizot and Kilbertus (1979), Frahm (1982aFrahm ( , b, 1985aFrahm ( , 1994Frahm ( , 2000)), Padberg and Frahm (1985), Stech (1999) and Ziljstra (1998).To define the novelty of records and distribution of species apart from the above were used Ah-Peng and Bardat (2005), Crosby et al. (1983), Een (2000), Frahm (1985bFrahm ( , 1993Frahm ( , 2021)), Frahm et al. (2009), Frahm and Ho (2009), Frahm et al. (2012), O'Shea (1995O'Shea ( , 2006)), O'Shea et al. (1996), Tixier and Guého (1997).
We call East African or western Indian Ocean islands the group of isles eastwards from East Africa to the Rodrigues Island at the latitude of 63.5°E (see Fig. 1).These isles are geologically very different: the oldest are of Precambrian origin, as Madagascar and the Inner Seychelles, their base is built up of granite and gneiss, with different later deposits.Others are of volcanic

ENUMERATION OF THE SPECIES
The following abbreviations are used: COM = Comoro Islands, MAD = Madagascar, MAF = Mafia Island, MAU = Mauritius, REU: = Réunion, SEY = Seychelles.The first two digits of collecting localities means the year of the collection.All specimens are deposited both in EGR and B, except for those, which are marked by EGR.Tixier (1978) and Pócs (1997Pócs ( , 1999)), indicating a distribution mainly on the Indian Ocean islands belonging biogeographically to Africa, eastwards to the Rodrigues Island at 63.5° E longitude, but with occurrence also on the Crystalline Arc and other East African mountains.
Campylopus flexuosus (Hedw.)Brid.var.flexuosus -COM: Ngazidja (Grande Comore) Island.Col du Dibwani, "Plateau des Fougères" between Bahani and Koimbani villages at 560 m, in remnants of dry forest, Pócs, Magill & Rupf 9263/AC.-Almost pantropical species distributed also in the Atlantic part of Europe.The commonest species of shady and half-shady habitats on all islands from the sea level to the upper forest limit, collected from 16 habitats in many specimens from the Indian Ocean islands, but proved to be new to the Comoros.

DISCUSSION
Analysing the distribution of Campylopoideae species of the Indian Ocean islands, it turned out that only one strictly endemic taxon occurs there, what is a vicariant subspecies of a South American species.It is surprising, comparing to the vascular or cryptogamic floras of Madagascar and neighbouring islands.According to estimates, the Indian Ocean islands have 20% of liverwort endemics (Vanderpoorten and Hallingbäck 2008, based on Wigginton pers. comm.) and Réunion Island has 14% of moss endemics (Ah Peng et al. 2010).The low number of endemics among the Campylopus taxa of the area may be interpreted by the relatively small spore size: 7.2-15 µm (Luizi-Pronzo and Barth 1999) and the ability of vegetative reproduction of most Campylopideae, which both enhance long range air dispersal (Zanten and Pócs 1981).At the same time there are three bicontinental (Afro-American) disjuncts, all of them occur in altimontane habitats.
There is a good number (8) of subendemic, so called Lemurian taxa, which are widely distributed on the islands, but occur also on continental SE Africa, mainly in the Precambrian crystalline mountains.This seems to confirm a possibility of short range, step by step dipersal or the importance of land connection before the Cretaceous between mainland Africa and Madagascar (Pócs 1975(Pócs , 1999)).The distribution patterns of all known Indian Ocean island Campylopoideae taxa are the following:

Fig. 1 .
Fig. 1.The East African or western Indian Ocean islands, where the Campylopus specimens were collected.Abbreviations see under the title of Enumeration