NOTE Mossballs of Rigodium implexum (Rigodiaceae) on the Forest Floor in Chile

Abstract

high mountains, where moss cushions are elevated during night by growing ice needles and inverted every night by the same effect, thus producing a globular shape. Other mossballs are known from lakes, where submersed mosses are detached from the ground during storms, formed into oval balls by the surf, and deposited on the beach where they accumulate in masses. At least one other type of forest mossball is known-balls of epiphytic mosses, such as Dicranoloma billardieri in New Zealand, Chile, and central Africa, or hepatics such as Lepicolea spp. in southeast Asia and again in New Zealand and Chile. These grow in the canopy and can reach enormous dimensions (one m in diameter). They accumulate so much dust and humus that they can even break branches and fall, providing phytomass accumulated from the atmosphere for the ecosystem. The mossballs of Rigodium, however, grow on the forest floor. They are 10-20 cm in diameter and usually lay in masses of several dozens to more than a hundred in shallow depressions, densely matted together, unattached to the ground. The leaves are minute, scale-like and hard to see with the naked eye. Occasionally they are found in smaller quantity, which may be a result of wind dispersal. Most floristic publications do not mention this strange life and growth form, which cannot classified into a known category. Herzog et al. (1939) mentioned that Rigodium implexum covers large areas in forests at low elevations. Oberdorfer (1960), in his survey of the vegetation units of Chile, mentions extended mats of loose balls of Rigodium implexum as characteristic for the Nothofag s oblique/Persea lingue forest. Every mossball consists of a single plant that is densely branched (Zomlefer 1993, fig. 40). It keeps the globose form in both dry or wet states by a stiffness of the branches, that is also typical for other species of Rigodium. Perhaps this is the reason that this genus was able to generate such forms. In fact, we came to the conclusion that this must be a species of Rigodium because of its distinct touch.