Cheilolejeunea androproliferans C.J. Bastos & Schäf.-Verw., 2025

Cheilolejeunea androproliferans C.J. Bastos & Schäf.-Verw. , sp. nov. Fig. 1 View FIGURE 1 .

Plant similar to Cheilolejeunea papulosa but differing in its much smaller size, suberect leaves, a smaller underleaf with sinus acute to lunate, and asexual reproduction by cladia, including production of cladia on stem of androecial branches.

Type :— BRAZIL. Pará: Serra do Cachimbo an der BR 163 nahe Cachimbo, epiphytisch in feuchtem Sekundär-Regenwald ; ca. 500 m, 7 July 1989, A. Schäfer-Verwimp & Verwimp 11356 ( holotype ALCB; isotype SP, hb. Schäfer-Verwimp) .

Main axis including leaves 340−430 µm wide, vegetative branches Lejeunea - type with conspicuous basal collar. Stem 50 µm in diameter, in cross section with 7 epidermal cells and 3−4 medullary cells; ventral merophyte two cells wide. Leaves imbricate, suberect; lobe suborbicular, 170−215 µm long × 150−195 µm wide, dorsal margin slightly arched, entire, ventral free margin straight, usually continuous with the keel of the lobule, entire, apex obtuse to acute to rounded, plane; cells hexagonal to oblong to isodiametric, 18−30 µm long ×13−18 µm wide, strongly mammillose, trigones minute, intermediate thickenings absent; oil bodies not observed; ocelli absent; lobule inflated, ovate, 95−120 µm long × 70−85 µm wide, ca. 1/3−1/2 of the leaf length, free margin involute, second and first teeth evident, contiguous or parallel, generally the first tooth is prominent, hyaline papilla situated in the notch between the two teeth or not conspicuous, keel arched with cells strongly mammillose. Underleaves distant, small, 80−105 µm long × 75−110 µm wide, slightly longer than wide, sometimes slightly wider than long, ca. 1.0−2.5× stem width, sinus V-shaped to U-shaped, lobes triangular-acute, bases cuneate, insertion line slightly curved. Autoicous. Androecia on main branch or on lateral branches or intercalary and proliferative, 2−4 pairs of bracts, 1−2 bracteoles at the base of the branch. Gynoecia terminal on main branch or on short lateral branch, bract lobes obovate, 430 µm long × 370 µm wide, margins entire, apex rounded, mostly curved, bracteole narrowly ovate, bifid, 400 µm long × 280 µm wide. Perianths pyriform, 530 µm long × 550 µm wide, 5-keeled, beak short, 25 µm long, 1−2 cells long. Vegetative multiplication by cladia, sometimes arising from the stem of androecial branch.

Additional specimens examined:— BRAZIL. Amazonas : between Manaus and São Gabriel, São Luiz, 00°10’S, 63°00’W, in secondary forest, 28 July 1979, R. M. Schuster 79-4-103, 79-4-117 ( F) GoogleMaps ; NW of São Gabriel, near mouth of Rio Uaupés , 00°08’S, 67°10’W, riverside forest, 21 July 1979, R. M. Schuster 79-20-1025 ( F). Manaus , Rio Negro, Praia da Lua, 3°02’04.9”S 60°09’32.5”W, floresta sazonalmente inundada (Igapó), epífita, 25 November 2016, A. M. Sierra 4592 ( INPA; ALCB) GoogleMaps .

Etymology:—In reference to the production of cladia in the androecial branch.

Distribution and habitat:—The species so far known to be restricted to the states of Amazonas and Pará, since no other specimens were found in collections examined.

Notes:— Due to morphology of the gynoecial bracts and bracteoles, appearance of the cells of the dorsal leaf lobe, and number of stem medullary cells, the new species is similar to Cheilolejeunea papulosa . However, C. androproliferans presents more strongly mammillose keel cells, suberect leaves with a lobe ca. 2× the length of the lobule, underleaves with broadly acute to lunate sinus (U-shaped), smaller trigones and asexual reproduction by cladia. A striking feature of the new species in relation to asexual reproduction is the production of cladia on the androecial branch. Although the holotype presented a monoicous sexual condition, the material from the State of Amazonas had only androecial branches and no production of cladia.

Due to the strongly mammillose keel cells, small underleaves and small size of the gametophyte, C. androproliferans may resemble some phenotypes of Cheilolejeunea savannae Macedo, Ilkiu-Borges & Bastos (2020: 79) ( Macedo et al. 2020). However, the presence of two adjacent or overlapping teeth in the leaf lobule and the absence of innovations indicates that they are different species.