Bryophyte flora of Uganda. 1. Jungermanniaceae

Abstract

Plants forming dense to loose patches or mats, rarely scattered among other bryophytes. Shoots small to robust, mostly 5–100 (or more) mm high and 0.1–10 mm wide, creeping, prostrate, ascending, suberect to erect. Stems mostly with weakly differentiated cortical cells, sometimes hyalodermis of larger cells present. Branching not common, terminal or lateral-intercalary, very rare ventral-intercalary in form of stolons. Rhizoids scattered on the ventral face of stem, rarely originating from leaf base or leaf cells. Leaves mostly obliquely, rarely subtransversely inserted, succubous, alternate, dorsally extended to stem midline, not decurrent, slightly decurrent or longly decurrent, mostly unlobed, rarely retuse to shallowly bilobed; leaf margins entire. Underleaves only in some genera; if present, small, lanceolate to bilobed. Leaf cells thin-walled, mostly collenchymatous, with distinct or bulging trigones, rarely parenchymatous, with missing trigones. Cuticle smooth to verruculose. Oil-bodies (1–) 2–9 (–12) per cell, mostly ovoid, granulose; rarely homogenous. Asexual reproduction only in some species, mostly by 1–2-celled gemmae; endogenous gemmae in one species (Jungermannia caespiticia). Dioicous or paroicous, exceptionally heteroicous plants. Androecia terminal, becoming intercalary or subgynoecial, spicate. Antheridia 1–3 (–6) per bract, ovoid, with 1–2-seriate stalk. Gynoecia terminal on main shoots, with 1 (–3) pairs of bracts. Perianth present (in some genera double), exserted or hidden by the bracts, sometimes reduced and partially replaced by perigynium. Seta with numerous cells rows. Capsule ovoid to spherical, 4-valved, with 2 (–5)-stratose wall; epidermal layer cells with nodular, inner layer cells with semiannular thickenings. Spores finely papillose; elaters mostly 2-spiral, rarely 1– or 3–4-spiral.