Sphaerolejeunea umbilicata (Lejeuneaceae), a critically endangered epiphyllous liverwort of the Andes M. Elena Reiner-Drehwald1 & Uwe Drehwald2
1Georg-August-Universität Göttingen, Albrecht-von-Haller  Institut für Pflanzenwissenschaften, Abteilung Systematische  Botanik,  Untere Karspüle 2, 37073 Göttingen, Germany 2 Justus-Liebig-Universität Giessen, Zentrum für internationale Entwicklungs- und Umweltforschung,  Otto-Behaghel-Str. 10D, 35394  Giessen, Germany

Introduction Sphaerolejeunea Herzog, a monospecific neotropical genus of the large family Lejeuneaceae, was known until now only from the  80-year-old type material of S. umbilicata Herzog. It was collected by E.  P. Killip in a lower montane rainforest at 1400-1800 m, in the Andes of Colombia (Herzog 1938). During field work in northern Peru in January  2001, the second author rediscovered Sphaerolejeunea umbilicata growing on living leaves in a lower montane rainforest.

Fig. 1: Sphaerolejeunea umbilicata Herzog

Morphology and systematic position of  Sphaerolejeunea Sphaerolejeunea (Fig. 1) is characterized by the following main  features:  adult leaf lobe bordered by 1-4 rows of dead, hyaline cells, lobule inflated,  plants freely fertile, gametoecia not exceeding the  vegetative leaves (Fig. 4), and perianth inflated, without keels or  beak. Based on the characters of the sporophyte (Fig. 5), observed in  the Peruvian collection for the first time, Sphaerolejeunea is a member of the tribe Lejeuneae Dumort. (subfamily Lejeuneoideae). The morphological similarities between Sphaerolejeunea and Lejeunea (they share a similar  stem anatomy, bifid underleaves, innovations of the same type and similar capsule valves) suggest that Sphaerolejeunea is closely related to Lejeunea and may be its sister group.

Distribution and ecology  Sphaerolejeunea umbilicata is only known from two localities in  the northern Andes (Fig. 2): Colombia (Dept. Cauca, the type) and Peru (Dept. San Martín). The plants were collected as epiphylls in forests, between 1300-1800 m. In Peru the species was found in a lower montane  rainforest, only slightly disturbed, in an area entirely built of  limestone. The species was restricted to humid sites in the understory of the forest, close to a temporary stream. The plants at the Peruvian site  grow closely appressed (Fig. 3) to the leaves of approximately 10 different species of trees and shrubs, including palm leaves and ferns. Sphaerolejeunea umbilicata was found covering large parts of the substrate, and was mainly associated with epiphyllous lichens, rarely with  a few stems of other bryophytes, including Crossomitrium epiphyllum  (Mitt.) Müll. Hal., Aphanolejeunea sp., Lejeunea laetevirens Nees &  Mont., and Odontolejeunea lunulata (F.Weber) Schiffn.

Fig. 2: Distribution of Sphaerolejeunea umbilicata

Conservation The ecological data from Peru suggest the species is restricted  to humid places in primary forests with a very low degree of disturbance. We do not know wether the fact that Sphaerolejeunea was found in a limestone area is of any importance for explaining its limited distribution. Gradstein (1992) considered Sphaerolejeunea umbilicata a critically endangered species. In spite of its rediscovery, S. umbilicata may still be considered critically endangered (CR, B1, 2c, Hallingbäck & Hodgetts 2000) because: the area where it is present in northern Peru is very small  (ca. 15,000 m²) the species may be extinct in its original collection site as  it was not recollected since 1922, and  the habitat where the species occurs is strongly declining.

Fig. 3. Sphaerolejeunea  umbilicata on leaf	Fig. 4. Sector of  plant	Fig. 5. Perianth   with opened capsule
References: Gradstein, S.  R. 1992. Threatened bryophytes of the neotropical rain forest: a status report. Tropical Bryology 6: 83-93. Hallingbäck, T. & N. Hodgetts  (compilers). 2000. Mosses, Liverworts, and Hornworts. Status Survey and Conservation Action Plan for Bryophytes. IUCN/SSC Bryophyte Specialist Group. IUCN, Gland, Switzerland and Cambridge, UK. Herzog, T. 1938. Sphaerolejeunea, eine neue Gattung der Lejeuneaceae Schizostipae. Annales  Bryologici 11: 86-89. Reiner-Drehwald, M. E. & U. Drehwald (2002). Sphaerolejeunea umbilicata (Lejeuneaceae), a critically endangered epiphyllous liverwort of the Andes. The Bryologist 105(3):422-430.  Fieldwork of the second author was financed by the Commission of the European Communities (Contract N°.  IC18-CT98-0259).   <<Home Lejeunea page Bryomonitor - a biomonitoring program for Neotropical rainforests Bryobrain - a neural network classifier for European foliose liverwort genera