Gleicheniaceae

Abstract

Gleicheniaceae is a family of Pteridophyta, in the order of Gleicheniales, consisting of 6 genera with approximately 165 known species, mostly distributed in tropical and subtropical regions. Plants are medium- to massive-sized, terrestrial. Rhizomes are often long, creeping, branched, and vitalized protostelic, covering with scales or multicellular hairs. Fronds are remote, monomorphic, with terete, long stipes, apex forked, with a dormant bud. Apical bud is covered with hairs or scales. Rachis is simple to several times pseudodichotomously branched or pinnate, with stellate hairs or ciliate scales when young. Fronds are 1-pinnate, pinnules pectinately pinnatisect. Pinnae are 1–2-pinnate, terminal or pinnules linear. Veins are free or dichotomous or multi-fork. Fronds are papery or subleathery, often glaucous abaxially. Sori are small, rounded, consisting of 2–10 sporangia, without indusium, bearing on small veins abaxially, in 1 serial between frond midvein and margin, seldom in 2–3 series. Sporangia are turbinate and an annulus around middle. Spores are blunt triangular in polar view, semicircular in equator view, trilete or single crack, with perispore or without, superficially smooth. Two species, belonging to different genera, are illustrated in the chapter.