Taxonomic and floristic notes on neotropical Macromitrioideae (Orthotrichaceae)

Upon examination of type material, the following new synonymies are proposed: Macromitrium altituberculosum Bartr. with M. carionis C. Muell.; M. aureum C. Muell. with M. longifolium (Hook.) Brid.; M. crumianum Steere & Buck with M. leprieurii Mont.; M. semimarginatum C. Muell. with Groutiella chimborazense (Spruce ex Mitten) Florsch.; M. standleyi Bartr. var. subundulatum Bartr. with M. fulgescens Bartr. In addition, the following synonymies were confirmed: M. brevipes C. Muell. with Groutiella apiculata (Hook. & Grev.) Crum & Steere; M. sartorii C. Muell. with M. punctatum (Hook. & Grev.) Brid. Floristic reports include M. leprieurii new to Dominica, Guadeloupe, and Panama, and M. ulophyllum Mitten is reported for the first time from Central America (Panama) and Venezuela. A complete description including illustration is provided for the first time for the latter species. Lectotypes are chosen for all types examined. While working on the Macromitrium flora of Panama and the Lesser Antilles (Guadeloupe and Dominica) several type specimens of neotropical taxa were examined. Taxonomic and floristic observations are presented here while a complete floristic account will be discussed later. Groutiella apiculata (Hook.) Crum & Steere (Bryologist 53: 146, 1950). Basionym: Orthotrichum apiculatum Hook. (Musci Exot. 1: 45, 1818). Typus: Mexico, “prope Xalapam in Regno Mexicano, regione temperata. Humboldt et Bonplant” (Isotypus: NY!). Syn.: Macromitrium brevipes C. Muell. (Synopsis Muscorum Frondosorum 1: 728, 1849). Typus: “Insulae Martinique: Hb. Fe•’e, Guadeloupe: Bertero, Trinidad: Sieber.” (Lectotypus, here designated: Insulae Trinidad, Sieber 28; HBroth!). From the three collections used for the original description, only one was found in Brotherus’ herbarium. The specimen by Sieber is chosen as the lectotype. It includes two creeping stems with a few erect branches. The first one clearly belongs to Groutiella apiculata: the basal cells are short, the margin is well differentiated in the lower half of the leaf, the costa forms a prominent apiculus, and the leaf-margins are strongly revolute when dry. According to Mueller’s description, there is little doubt that this was part of the specimen described under M. brevipes. The second stem belongs to Macromitrium. The