Michael Lüth
Emmendinger Strasse 32, D-79106
Freiburg, Germany, fax: +49 761 280944,
email: milueth@hotmail.com
Abstract – Dicranum transsylvanicum Lüth is
described and illustrated as a new species from the Apuseni Mountains in
western Romania. The new species resembles D.
scoparium Hedw. in habit and D.
crassifolium Sérgio, Ochyra & Séneca in microscopic details, especially
in its partially bistratose lamina cells in the upper half of the leaf, but
differs in having a strongly spinose leaf lamina on the dorsal side,
irregularly dentate leaf margins in the upper part and a triangular stem in
transverse section.
In summer 2000 I
accompanied Prof. Dr. Albert Reif, University of Freiburg, to Ghetar in the
Apuseni Mountains in West Romania, to prepare a project for a nature reserve
and agricultural development.
It is a
mountainous region with an average altitude of 800-1000 m with higher peaks of
1500-1800 m. The area surrounding the 1000 m high village of Ghetar was settled
100 years ago. Prior to settlement, a few people lived in the valleys but the
higher areas were reserved for the bears, lynxs and wolves. Today there are
small villages in clearings with a little agriculture and many lumberjacks. The
most important tools in the area are the horse and the power saw, but more
recently, a very few people have acquired a tractor or car: the region is
starting slowly to connect with modern times. The project from the University
of Freiburg is to study the vegetation, agriculture and social life with the
objective of allowing change to continue without destroying the natural
environment and social structures.
During those
studies, we took a relevé in a forest with beech, fir and spruce on a rocky
steep slope. In this relevé I found a puzzling Dicranum on spruce needle litter between limestone boulders, that
could have been either D. scoparium
Hedw. or D. polysetum Sw., as it had
characteristics of both. A sample was taken for examination.
The first look
down the microscope brought a big surprise: the lamina was partly bistratose,
the costa had up to 6 lamellae and there were teeth on the lamina. In some
parts it reminded me of the newly described Dicranum
crassifolium Sérgio, Ochyra & Séneca (1995) from Portugal, but when I
compared it with that plant I was certain that it was not the same. I sent part
of the specimen to Michael Sauer, Germany, who worked with Dicranum for the handbook „Die Moose Baden-Württembergs“ (Sauer,
2000) and had examined a lot of material from Central Europe, to Thor-Björn
Engelmark, Sweden, who knows Dicranum
from all over Europe and to Ryszard Ochyra, Poland, who has examined Dicranum from several places of the
world and who contributed to the description of D. crassifolium. The result of this inquiry to the experts was that
this was an unknown Dicranum, an
undescribed new species.
Dicranum
transsylvanicum
Lüth sp. nov. (Fig. 1) Photo
Diagnosis – Species haec D.
scopario similis sed recedit foliis
erecto-patentibus vel patentibus, torsivis et aliquando parce undulatis,
marginibus in parte superiore irregulariter hamato-dentatis, laminis distali
bistratosis dorso fortiter spinosis, caule in sectione transversali triangulari
et ducto centrali distinctissimo praedito et costis dorso sulcatis, lamellis
4-6-seriatis instructis.
Type – ROMANIA, Transsylvania, Apuseni Mountains,
District Scarisoara, Ghetar. Mt. Bocului, alt. ca 1150 m, rocky east-facing slope in forest dominated by beech (Fagus sylvatica), spruce (Picea abies) and fir (Abies alba); on
spruce needle litter between limestone boulders, Rel. No. 940, 31 August 2000, Lüth 3154 (Holotype: STU; isotype:
KRAM).
Description – Plants, large and fairly robust, in rather loose, green to
brownish-green tufts. Stems erect,
4-6(-7) cm high, dark brown, glossy, mostly simple, sometimes sparingly
branched, usually densely matted with a tomentum of branched, smooth rhizoids,
whitish above, brownish below, in cross-section usually triangular with concave
sides, epidermis with 1-3 layers of small, strongly thick-walled and
reddish-brown cells, cortical cells in 3-5 layers, wider, rather thin-walled
with small corner thickenings, orange, central strand present,
distinct, medium-sized. Leaves
equally spaced along the stem, usually more crowded at the apex, straight or
rarely falcate-secund, sometimes spirally twisted and weakly undulate, mostly
erecto-patent to spreading, ovate-lanceolate, gradually long acuminate, concave
throughout, 1,3-1,6 mm wide, 6-9 mm long. Margins
plane, entire below, strongly toothed above, with irregular, long and spinulose
teeth composed of 1-6 cells. Costa
single, concolorous or sometimes somewhat brownish, 100-160 µm wide at base,
gradually tapering upwards, ending near the apex, in the upper part winged with
4-6 prominent dorsal lamellae of up to 5 cells, up to 30(-50) µm high, strongly
toothed with irregularly spinulose, often characteristically hook-shaped teeth,
in cross-section with a single row of large guide cells and two stereid bands,
at the back often with one row of larger epidermal cells, mainly in the lower
smooth part of leaf. Laminal cells
unistratose below, irregularly bistratose above with numerous 1-2 cell high
teeth on the dorsal side of lamina in upper half, elongate and porous
throughout, oblong and strongly porose in the lower part, 50-150 µm long, 8-12
µm wide, becoming shorter and less porose in upper part, 20-40(-50) µm long,
8-12 µm wide. Alar cells inflated, brown, bistratose, shortly rectangular to
oval, 50-80 µm long, 30-40 µm wide, lacking pores, thin walled. Sporophytes unknown.
Etymology – The species name refers to the area,
Transsylvania, where it was found. The area reminds us of Dracula and his
vampires, as also do the long teeth of the lamina and the lamellae of this
species.
Dicranum transsylvanicum is a very distinct and unmistakable
species. Its habit is somewhat intermediate between D. scoparium and D.
polysetum and in its microscopic characters it is similar to D. crassifolium. It shares with both D. scoparium and D. crassifolium the lamellose costa and with the latter also the
partially bistratose leaf laminae in the upper half. This character immediately
precludes any alliance with D. scoparium in
which the leaf lamina is consistently unistratose. D. transsylvanicum differs from D.
crassifolium and from other species of the genus in its strongly
spinose-dentate leaf margin. The marginal teeth are usually long, composed of up
to six cells, hook-shaped and often with additional spines at margins.
Moreover, the dorsal side of the lamina and dorsal lamellae of the costa are
spinose, a feature unknown in any European species of the genus. A further
difference from D. crassifolium and D. scoparium is the triangular stem with
a distinct central strand clearly visible in cross-section.
Up to now, D. transsylvanicum is only known from a
single station, but it is likely that additional specimens may exist misnamed
in herbaria. Therefore the European material of the D. scoparium complex is urgently in need of revision and this may
result in discovery of additional specimens of both D. transsylvanicum and D.
crassifolium. It seems that the genus is underinvestigated in Europe and
the recent discovery of another new species, D. dispersum, in Germany (Engelmark, 1999) is the best confirmation
of this statement.
Acknowledgments - I am grateful to Michael Sauer
and Thor-Björn Engelmark who verified my examination of the specimen and
supported my opinion that it was a new species. I am also much indebted to
Ryszard Ochyra, who compared my material with various species of Dicranum from outside Europe and made me
sure that a new species was at hand. He also encouraged me to complete this
paper and helped me with the Latin diagnosis and improvements in the text. The
excellent drawings of Halina Bednarek-Ochyra I always consider as an inspiring
paragon. I thank also Brian O‘Shea for correcting my English. Special thanks
are due to Albert Reif, who invited me to participate in the expedition to
Romania.
ENGELMARK T.-B., 1999 — Dicranum dispersum spec. nov. (Dicranaceae: Bryopsida: Bryophyta). Stuttgarter Beiträge zur Naturkunde Serie A (Biologie) 592: 1–8.
SAUER M., 2000 — Dicranales, Dicranaceae. In: NEBEL, M. & G. PHILIPPI (Eds.), Die Moose Baden-Württembergs. Stuttgart, Verlag Eugen Ulmer. 1: 129-220.
SÉRGIO, C., OCHYRA R. & SÉNECA A., 1995 — Dicranum crassifolium (Musci,
Dicranaceae), a new species from southern Europe. Fragmenta Floristica et Geobotanica 40(1): 203-214.
