FIGURE 1. A. Leiosporoceros dussii (Stephani 1893: 142) Hässel (1986: 255), Panama. Female plant with sporophyte. The gametophyte shows the blue-green looking Nostoc strands. B. Anthoceros sp., Australia. A monoicous plant showing some immature sporophytes. C. Phaeomegaceros coriaceus (Stephani 1916: 991) Duff et al. (2007: 241), New Zealand. Fan-shaped overlapping gametophytes with marginal gemmae in each lobe. D. Phaeomegaceros hirticalyx (Stephani 1916: 966) Duff et al. (2007: 241), New Zealand. The orange-brownish sporophytes contrast with the velvety appearance of the gametophytes. The gametophytes are covered with dorsal outgrowths. E. Dendroceros validus Stephani (1917: 1016), New Zealand. The species grows on shrubs and leaves. F. Nothoceros giganteus (Lehm. et Lindenb. in Lehmann 1832: 25) Villarreal et al. (2007: 283), New Zealand. The only species of the genus Nothoceros outside of the American continent. The luxurious appearance of the species is due to the extensive development of "wings" over the wide midrib, giving a "lettuce-like" look characteristic of the species. G. Dendroceros crispatus (Hooker 1813: 117) Gottsche et al. (1846: 579), Australia. Scanning electronic micrograph (SEM) of a dehiscing sporophyte with green multicellular spores and golden pseudoelaters. Notice the short epidermal cells. SEM colored by Andy Long. H. Leiosporoceros dussii (Steph.) Hässel, Panama. Autofluorescence of tetrads and elaters. The smooth bean-shaped spores are in bilateral-alterno opposite tetrads (yellow-green) and are interspersed by elongated pseudoelaters; both spores and pseudoelaters contain plastids (red). I. Notothylas temperata Hasegawa (1979: 20). Japan. Transverse section of the sporophyte showing tetrads (brown) with pseudoelaters in "shelves". The central columella is physically connected to a pseudoelater chain. Scale bars: A–F= ca. 10 mm; G= 50 µm; H= 30 µm; I=40 µm.

Published as part of Villarreal, Juan Carlos, Cargill, D. Christine, Hagborg, Anders, Söderström, Lars & Renzaglia, Karen Sue, 2010, A synthesis of hornwort diversity: Patterns, causes and future work, pp. 150-166 in Phytotaxa 9 on page 152, DOI: 10.11646/phytotaxa.9.1.8, http://zenodo.org/record/10084140