Lejeunea (Crossotolejeunea) Spruce (Spruce 1884

Lejeunea subg. Crossotolejeunea Spruce (Spruce 1884: 161) Crossotolejeunea (Spruce) Schiffn. (Schiffner 1893: 127) Type species Lejeunea boryana Mont. (lectotype, designated by Vanden Berghen 1945). Description Plants mostly dioicous (in about 70 % of the analysed species). Oil bodies granular (very rarely homogeneous). Male bracteoles restricted to the base of the male spike or occurring throughout. Female bracts and bracteole free or shortly connate on one side (broadly fused on both sides in sect. Echinocolea). Asexual reproduction by specialized devices rather common, including caducous leaves (or leaf lobes), caducous branches, and strap-shaped gemmae. In addition, vegetative reproduction by shoot fragmentation occurs in several sections. Distribution Pantropical, with some species extending into temperate regions. Species Eighty three species were found to belong to this subgenus. Notes The typical characters of subg. Crossotolejeunea are the predominance of dioicy, granular oil bodies, female involucre free or only shortly fused at the base, and the common presence of specialized devices for asexual reproduction. The commonness of asexual reproduction in the subgenus may be explained by the predominantly dioicous sexual system, causing an impediment to sexual reproduction (Devos et al. 2011; Kraichak 2012). Based on the results of the analyses, subg. Crossotolejeunea is subdivided into 11 sections: sect. Apolejeunea, sect. Crossotolejeunea, sect. Echinocolea, sect. Flavae, sect. Heterolejeunea, sect. Inflatolejeunea, sect. Minutilobae, sect. Nanolejeunea, sect. Papillolejeunea, sect. Sordidae, and sect. Xenantholejeunea.