A conspectus of the subfamily macromitrioideae (Bryopsida : Orthotrichaceae) in Southern Africa

In southern Africa the subfamily Macromitrioideae (Orthotrichaceae) consists offour genera, 11 species, and one subspecies. The following taxa are recognised.: Macrocoma, consisting of M. lycopodioides (Schwaegr.) Vitt, M. pulchella (Hornsch.) Vitt, and M. tenue (Hook. & Grey.) Vitt subsp. tenue; Macromitrium, consisting of M. lebomboense Van Rooy, M. levatum Mitt., M. macropelma C. Mill., M. richardii Schwaegr., and M. serpens (Hook. & Grey.) Brid.; Schlotheimia, consisting of S. ferruginea (Hook. & Grey.) Brid., S. percuspidata C. Mill., and S. rufopallens C. Muill.; and Cardotiella secunda (C. Miull.) Vitt. Lectotypes are selected for several of the southern African names. The family Orthotrichaceae can be divided into four subfamilies as proposed by Vitt (1972). The subfamilies Zygodontoideae, Orthotrichoideae, and Macromitrioideae, established by Brotherus (1925), occur in southern Africa. The fourth subfamily, Drummondoideae, was described by Vitt (1972). The Macromitrioideae are characterised by: a) prostrate primary stems with erect or ascending secondary branches, b) dimorphic leaves, c) branch leaves frequently twisted or inrolled, d) small, oval, rounded or quadrate, and frequently papillose upper leaf cells with incrassate walls, e) dwarf male plants frequently present in some genera, f) the frequent occurrence of anisospory in some genera, g) setae of intermediate length, h) phaneropore stomata, i) frequent fusion and reduction of peristome parts, and j) mitrate, frequently hairy calyptrae. The Macromitrioideae consist of eight genera, widely distributed in tropical, subtropical and southern temperate regions. The subfamily has never been the subject of a detailed systematic treatment and the most recent inclusive treatment of southern African taxa is that by Sim (1926). Vitt (1980b) included the southern African species of Macrocoma (Hornsch. ex C. Mill.) Grout in a monograph of the genus and later reported two species of the newly established Cardotiella Vitt from the region (Vitt 1981). The genera Macrocoma, Macromitrium Brid., Schlotheimia Brid., and Cardotiella occur in southern Africa. The genus Schlotheimia was originally described by Bridel (1812). He later refined the genus (Bridel 1826) and included four species in his treatment. Approximately 134 taxonomically valid names have been proposed in the genus (Gangulee 1976; Vitt 1989). The genus has never been monographed and until the recent revision of Schlotheimia in Australia and New Zealand (Vitt 1989), no critical revision of the genus existed. Nine species were described from southern Africa, one originally as a species of Orthotrichum Hedw. Sim (1926) recognised four species [Schlotheimia ferruginea (Hook. & Grey.) Brid., S. grevilleana Mitt., S. percuspidata C. Miill., and S. rufoaeruginosa C. Mill.] in his treatment of the southern African taxa. The same four species as well as S. ventrosa C. Miill. were listed for southern Africa by Magill and Schelpe (1979). Macromitrium was originally described by Bridel (1819). Vitt (1982a) estimated that the genus contains about 260 species. The genus has recently been revised for New Zealand (Vitt 1983) and Australia (Vitt & Ramsay 1985a). Twelve species were described from southern Africa of which three were originally described as species of Orthotrichum. Sim (1926) recognised eight species ofMacromitrium for southern Africa while Magill and Schelpe (1979) included six species [M. levatum Mitt., M. macropelma C. Miill., M. schlotheimiaeforme Par., M. secundum C. MUll., M. serpens (Hook. & Grev.) Brid., and M. tristratosum Dix.] in their checklist. The southern African taxa have not been revised since Sim's 1926 treatment. Miller (1849) recognised eight species in his Macromitrium section I, Macrocoma. Grout (1944) elevated Miiller's section Macrocoma to generic level and included two species in the genus. Macrocoma 0007-2745/92/205-215$1.25/0 This content downloaded from 157.55.39.107 on Wed, 30 Mar 2016 05:28:31 UTC All use subject to http://about.jstor.org/terms 206 THE BRYOLOGIST [VOL. 95 has recently been revised by Vitt (1973, 1980b) and in 1980 he recognised nine species in subgenus Macrocoma and two species in subgenus Trachyphyllum (Broth.) Vitt. The three southern African species treated by Sim (1926) in Macromitrium section Macrocoma were transferred to Macrocoma by Vitt (1973) as M. lycopodioides (Schwaegr.) Vitt, M. pulchellum (Hornsch.) Vitt, and M. tenue (Hook. & Grev.) Vitt. The same species were included in Magill and Schelpe's 1979 checklist of southern African bryophytes. Vitt (1980a,b) selected lectotypes for the southern African names placed in Macrocoma. The genus Cardotiella was established by Vitt (1981). He recognised six species in the genus, including the two southern African species C. secunda (C. Milll.) Vitt and C. schlotheimiaeformis (Par.) Vitt, both originally described as species of Macromitrium. MATERIALS AND METHODS This conspectus of the Macromitrioideae in southern Africa is based on a taxonomic revision of the subfamily (van Rooy 1990a), submitted in partial fulfillment of the requirements for the M.Sc. degree in botany at the University of Pretoria, South Africa. The thesis includes a historical review of the subfamily, a chapter on materials and methods of study, a discussion on the taxonomic importance of gametophytic and sporophytic structures, a taxonomic treatment, and a chapter on the phytogeography and ecology of southern African taxa. Descriptions of the taxa and a list of the 804 herbarium specimens examined have been provided by van Rooy (1990a). The voucher specimens cited in this conspectus are housed in PRE unless otherwise indicated. Geographical regions referred to are similar to those presented by Magill (1981). Preparation for scanning electron microscopy was done as outlined in van Rooy (1990a).