Cell Division Patterns in the Peristomial Layers of the Moss Genus Two Hypotheses and a Third Solution.

The Chilean endemic genus belongs to the Gigaspermaceae, one of the most basal groups of arthrodontous mosses. While none of the species in this family has a peristome, earlier stages of sporophyte development often disclose its basic structure. The study of sporophytes at the early stages of development was conducted to identify possible similarities with , the genus sister to Gigaspermaceae plus all other arthrodontous mosses in the moss phylogenetic tree.

Are All Paraphyllia the Same?

Moss paraphyllia, the trichome-like or foliose structures on moss stem surfaces, are usually treated as epidermal outgrowths. However, in some taxa of the moss families Leskeaceae, Neckeraceae, and Amblystegiaceae their distribution along the stem is consistently correlated with parts of the stem surface near branch primordia. In other moss families, Climaciaceae, Hylocomiaceae, and Pseudoleskeaceae the specific paraphyllia-generating epidermal layer produces paraphyllia evenly all along the stem.