Lejeunea lumbricoides (Nees) Nees

Renner, Matt A. M., 2013, A new subspecies of Acrolejeunea arcuata, and notes on typification, synonymy, and distribution of other Australasian Lejeuneaceae, Phytotaxa 83 (1), pp. 39-53 : 49-50

Lejeunea lumbricoides (Nees) Nees in Gottsche et al. (1845: 342)

Jungermannia lumbricoides Nees von Esenbeck (1830: 40) .

Type:— INDONESIA. Java: without locality, Blume s.n. (not located).

Hygrolejeunea rostrata Stephani (1889: 172) , syn. nov.

Lectotype (designated here): — AUSTRALIA. Norfolk Island , February 1885, Isaac Robinson s.n., comm. von Müller, (element 1, separated as subpacket within G-23317!).

Like Hygrolejeunea norfolkensis , H. rostrata was treated as a synonym of L. discreta by Grolle (1981). The type material of H. rostrata is mixed, comprising two elements. The first, and more abundant of these is a large plant with large cordate underleaves, relatively small lobules, and gynoecia terminal on short lateral branches. The first element is a good match with L. lumbricoides . The second element is represented by several shoots, which have small ovate underleaves, and gynoecia terminal on leading shoots, and 5-carinate perianths. The second element is a good match with L. discreta .

The protologue of Hygrolejeunea rostrata describes several features unambiguously characteristic of element 1, including the stratified and pendulous shoots up to 8 cm long ‘without interruption’, the short branches sparsely arranged along shoots with terminal gynoecia. Perhaps the most unambiguous feature is the underleaf, which is large remote, six times broader than the stem, and cordiform with a deeply cordate base. As element one is a better match with these described features, Hygrolejeunea rostrata is lectotypified on it here, in accordance with the International Code of Nomenclature for algae, fungi, and plants (McNeil et al. 2012). On the basis of this lectotypification H. rostrata is properly a synonym of Lejeunea lumbricoides , not L. discreta . My conception of L. lumbricoides is based on the protologue and Mizutani (1970).

A duplicate of Robinson’s gathering in BM comprises mainly L. discreta , which is also fertile. The type gathering must have been split non-representatively when duplicates were created, and this may explain Grolle’s (1981) synonymy .

Distribution and ecology:— In Australia known only from Norfolk Island. No information on the ecology of the plants is provided with the type of H. rostrata , but given the pendulous habit, it was likely epiphytic in cloud forest.

Recognition:— Lejeunea lumbricoides is distinctive in its large size, with leading shoots up to 10 cm long bearing shorter smaller stature branches, and large remote cordate underleaves with deeply cordate bases. The size and underleaf shape alone should prevent confusion with other species of Lejeunea .