12,000 species found across the globe. One particularly interesting moss is Cyclodictyon plicatulum (Müll.Hal.) Broth., also known simply as Cyclodictyon. This small but mighty plant belongs to the Pilotrichaceae family and has some remarkable characteristics. Let’s take a closer look at this fascinating moss!
Before diving into the specifics of Cyclodictyon plicatulum, it’s helpful to understand some basics about mosses in general. Mosses are non-vascular plants in the division Bryophyta. They lack true roots, stems, and leaves, instead having simple leaf-like structures called phyllids. Mosses reproduce via spores rather than seeds and are found in a wide range of habitats, from arctic tundra to tropical rainforests.
Cyclodictyon plicatulum is a pleurocarpous moss, meaning it has a branching, mat-forming growth habit. Its phyllids are ovate-lanceolate in shape and have a distinctly plicate (pleated or folded) appearance, hence the species name “plicatulum”. The phyllids are arranged in a spiral pattern around the stem. Cyclodictyon has a fairly delicate texture compared to some other mosses.
Identifying Cyclodictyon to the species level requires examination of microscopic features. The leaf cells are elongate-hexagonal and the costa (midrib) is short and double. Capsules are ovoid and borne on long setae. With practice, Cyclodictyon plicatulum can be distinguished from similar species by its overall appearance and habitat.
Global Distribution and Habitat
Cyclodictyon plicatulum has a pantropical distribution, meaning it is found in tropical regions around the world, including Central and South America, Africa, Southeast Asia, and the Pacific Islands. It typically grows on tree trunks, branches, and logs in humid montane forests at elevations of 500-2500 meters. Cyclodictyon is often found in association with other epiphytic bryophytes and lichens.
Ecological Roles and Adaptations
Like other mosses, Cyclodictyon plays important ecological roles. It helps retain moisture and nutrients in forest ecosystems, provides habitat for micro-organisms and invertebrates, and can be a pioneer species in disturbed areas. Mosses are also excellent indicators of air quality and environmental health. Cyclodictyon has several adaptations that allow it to thrive as an epiphyte in tropical forests:
Its plicate leaves help channel water towards the stem for absorption
It can tolerate periods of desiccation and rehydrate quickly when moisture is available
From its pleated leaves to its global distribution, Cyclodictyon plicatulum is a prime example of the incredible diversity and resilience of mosses. The next time you’re in a tropical forest, take a moment to appreciate the intricate world of epiphytic mosses – you just might spot some Cyclodictyon! What other secrets do you think these ancient plants hold?
