Stuttgarter Beitrage zur Naturkunde
ar
3x Serie A (Biologie)
Wir Herausgeber:

Staatliches Museum für Naturkunde, Rosenstein 1, D-70191 Stuttgart

Stuttgarter Beitr. Naturk. Ser. A Nr. 592 8 S. Stuttgart, 10. 8. 1999

Dicranum dispersum spec. nov.
(Dicranaceae: Bryopsida: Bryophyta)

By Thor-Björn Engelmark, Stockholm

With 3 figures

Summary

Dicranum dispersum (Dicranaceae: Bryopsida: Bryophyta) is described as a new species.
Differentiating characters from other related taxa within the genus Dicranum, especially D.
crıspifolium Müll. Hal. are given. All important morphological characters and the habit are il-
lustrated. The paper also provides information concerning the ecology and distribution of the
new species, presently known from southwest Germany and southwestern and central Asia,
as well as distributional data of D. crispifolium (figured in a map).

Zusammenfassung

Dicranum dispersum (Dicranaceae: Bryopsida: Bryophyta) wird als neue Art beschrieben
und von anderen, nahestehenden Vertretern der Gattung Dicranum, insbesondere D. crispifo-
lium Müll. Hal. abgegrenzt. Die Arbeit enthält Abbildungen der wichtigen morphologischen
Merkmale und des Habitus und gibt Hinweise zur Okologie sowie zur Verbreitung der neu-
en, bisher in Südwestdeutschland und Südwest- und Mittelasien nachgewiesenen Art und des
nahe verwandten D. crispifolium (mit Verbreitungskarte).

Contents
te Inka 2 5 ok RA AL SEN | a oa 4
2 Description OP Direranum dıspersumspee.moy: 3... 1.0.0020 nennen duesensnneenn 4
Malic oon manctdistel UMONN orl eC. hen nen ee 5
AMD SCUSS IC ety ee ey. et oleic) axe, oaks Shannan Svea uh geen Maio eM 7
uNdenmonalspeennensseemp rg rn... 5 tro oir eases cs en ese ten. se oes 7
Gee Nelantiniled xeiie ito me nr me en he + oy: MMR emote ope nals vey tyes 8
Eee CI, Bh a) ARE OL TE Eo Te OEE eee 8

Bis...

STUTTGARTER BEITRÄGE ZUR NATURKUNDE Ser. A, Nr. 592

Dicranum dispersum spec. nov. (a-i, Holotype, S) and D. crispifolium Müll. Hal. (,
k, Isotype, NY). - a. leaves; — b. cross-section of leaf above middle; — c. cross-section
of costa near middle; — d. upper leaf margin and cells; — e. perichaetium; - f. sporo-
phyte, upper part;

CRANUM DISPERSUM SPEC. NOV

on of alar cells; — k. cross-section of leaf near middle.
e=4mm.

; . cross-sect
- Scale: a, f, g = 2mm; b = 60 um; c, d, h-k = 90 um;

g. male plant; — h-j

4 STUTTGARTER BEITRAGE ZUR NATURKUNDE Ser. A, Nr. 592
1. Introduction

When studying herbarium specimens of D. muehlenbecku Bruch & Schimp., one
old sample, collected in 1875, of an apparently new species was found. As this speci-
men seemed to be most closely related to east Asian taxa, e.g. in its partly three-
layered alar cell group, which separates it from all hitherto known European Dicra-
num taxa, it was rather surprising that, according to the label, it should have been
collected in Baden-Württemberg in Germany. Although the sample initially was
suspected to have been mislabeled, the given old locality was searched, and, on a vis-
it in 1979, the plant was rediscovered still growing in the very same place, and fur-
thermore at another locality some 50 km apart.

Since then, some additional herbarium specimens have been found, collected in
the same part of Germany as well as from several localities in Asia. The few times
this species had been collected or noted at all, it seems to have been confused with D.
muehlenbecki and D. scoparınm Hedw. Lately it has been collected by MicHAEL
SAUER during the work with the flora project of Baden-Württemberg (NEBEL &
PHILIPPI 1n press).

2. Description of Dicranum dispersum spec. nov.

Types: Germany, Baden-Württemberg, Sigmaringen, Oberschmeien, T. ENGELMARK,
May 13, 1980 (Holotype ın S, Isotype in STU).

Diagnosis: Planta speciosa, sat robusta, viridescens vel brunneo-viridescens.
Caules laxe caespitosi, ad 8cm alti, rhizoidiis fere ad apicem impliciti. Folia stricta
vel plus minusve flexuosa, patentia ad erecto-patentia, interdum falcata, in sicco
crispata, lanceolata, graciliter acuminata, paene ad apicem caniculata; lamina parte
alari bistratosa ex parte tristratosa, marginibus dimidio superiore bistratosi serratis;
cellulis superioribus et medianis quadratis, breviter rectangularibus vel irregulariter
angulatis; Pseudomonoica; folia perichaetialia interiora abrupte acuminata. Seta soli-
taria in quoque perichaetio 1.5-2.5cm longa, flava vel flavo-rubescens; theca
2.5-3.5mm longa, curvata, suberecta, in sicco valde curvata, horizontalis et sulcata;
sporae globosae vel ovoideae, minute papillosae, 16-21 um. Dicrano crispifolio
Müll. Hal. similis, sed parte alaria laminae bistratoso vel ex parte tristratoso haud
4—6-stratoso jam differt.

Morphology: Female plants (fig. 3) rather robust in loose green or brownish
green tufts. Stem with central strand, up to 8cm high, more or less matted with white
or reddish brown rhizoids, often nearly to apex. Leaves (fig. 1a) 6-8 x 0.8-1.2 mm,
smooth, straight to somewhat flexuose, erect-spreading to spreading, loosely crisped
when dry, ibaeeolere slenderly acuminate, apical part caniculate, lamina unistratose
except for partially bistratose upper margin and bistratose, sometimes in part tri-
stratose alar region, margins toothed in upper half; costa percurrent to shortly ex-
current, papillose on dorsal surface, with small teeth near apex, with a row of guide
cells and two stereid bands, the dorsal and ventral epidermal layers of cells differen-
tiated (fig. 1b, c); upper and median cells (fig. 1d) quadrate, short-rectangular or ir-
regularly angled, smooth or with scattered papillae, thin to moderately thick-walled,
nonpitted, 11-15 x 15-35 um, basal cells above the alar region rectangular, relatively
thin-walled, rarely pitted, 12-16 x 45-80 um, alar cells reddish to brownish, thin-

ENGELMARK, DICRANUM DISPERSUM SPEC. NOV. 5

Fig. 2. Approximate distributions of Dicranum dispersum spec. nov. (triangles) and D. cri-
spifolium Müll. Hal. (quadrats).

walled, in a broad band from the margin towards the nerve. Pseudomonoicous; male
plants (fig. 1g) dwarfed, attached to the rhizoids of female plants; perichaetial leaves
(fig. 1e) convolute, sheathing, abruptly acuminate. Seta single in each perichaetium,
1.5-2.5 cm long, yellow or pale reddish yellow; capsule (fig. 1f) 2.5-3.5mm long,
curved, suberect to horizontal, furrowed when dry; peristome teeth normal dicran-
oid ca 550pm; spores globose to ovoid, brownish yellow, minutely papillose,
16-21 pm.

3. Ecology and distribution

The type was found on a calcareous mountain slope facing west, in a mixed pine
and beech forest. The altitude of this locality is ca 700 m a.s.l. Dicranum dispersum
spec. nov. grew in pure, wide tufts together with Rhytidium rugosum, Homalothe-
cium lutescens, Rhytidiadelphus triquetrus, Campyliodelphus chrysophyllus, Hyloco-
mium splendens and Tortella tortuosa.

This new Dicranum derives its specific epithet from its dispersed known distribu-
tion. It is recorded hitherto from Central Europe and Asia. All European localities
known so far are within the boundaries of the province of Baden-Württemberg in
SW Germany. In this region, D. dispersum occurs quite widespread in the area of the
Suabian Alps (SAUER in press). The present knowledge indicates a wide but scattered

6 STUTTGARTER BEITRÄGE ZUR NATURKUNDE Ser. A, Nr. 592

Fig.3. Female plant of Dicranum dispersum spec. nov. — Actual size: 3 cm.

Eurasian distribution (fig. 2), and a restriction to calcareous areas. Samples from
Mongolia and the Alatau have been mixed with Rhytidium rugosum and Abietinella
abietina which suggests the ecology in these areas to be close to that in Europe.

ENGELMARK, DICRANUM DISPERSUM SPEC. NOV. 7
4. Discussion

All Dicranum species have at least some two- to many-layered alar cell groups, in
contrast, e.g., to the related genera Orthodicranum (Bruch & Schimp.) Loeske, and
Dicranoloma (Renauld) Renauld, where these always are only single-layered. In east
Asia, several Dicranum species constantly have multi-layered alar cell groups, but in
all other geographical areas the known Dicranum species never have more than just
two-layered alar cell groups. This new species, D. dispersum, has often sections with
a few three-layered alar cells (fig. 1h, i) and approaches in that respect some east
Asian taxa. Dicranum dispersum is most similar to D. crispifolium Müll. Hal., a
southeast Asian species, known from India, the Himalaya and SW China. Both spe-
cies have leaves channeled in the upper part with partly bistratose toothed margins,
a rather similar cell net, and when dry, leaves crisped in the same manner. D. crispi-
folium differs in having relatively longer and narrower leaves, upper lamina cells
much more papillose, alar cells (fig. 1)) in a narrower but much more swollen 3-6-
stratose structure forming a distinct reddish band sharply delimited from the hyaline
one-layered cells towards the nerve, the leaf nerve with not or poorly differentiated
ventral epidermal layer of cells (fig. 1k), and the seta longer, 3-5 cm, darker, reddish
brown. These two species are not sympatric anywhere where they are known to oc-
cur. In Asia D. dispersum obviously has a more northern distribution, north of the
Himalayan shield.

The likewise east Asian Dicranum thelinotum Mull. Hal. is also rather similar in
habit, but this species, like D. muehlenbecku, has tubulous leaves without a partial-
ly bistratose upper leaf margin. Unlike D. muehlenbeckii, this species has a leaf nerve
with the ventral epidermal layer of cells not or poorly differentiated. Further it has
often two setae originating from each perichaetium.

D. dispersum has been reported as a probable hybrid between D. scoparium and
D. muehlenbeckü (EGGLER 1916) and as D. muehlenbeckit (EGGLER 1926, FROEH-
LICH 1950). This last-mentioned species, though similar in ecology, is very different
in its tubulous leaves, and in an unistratose lamina also in the upper leaf margin, and
even in the field is easily recognizable by its smaller size, and in dry condition, by
much stronger crisped leaves. Among the European species D. dispersum, with its
loose crispation, would in habit be most similar to a strong long-leaved plant of D.
spadiceum J. E. Zetterst. This species differs in the same characters mentioned for D.
muehlenbeckü and further by not having a stem with a thick tomentum, and the leaf
cells more thickened and porous. Dicranum brevifolium (Lindb.) Lindb. has chan-
neled leaves like D. dispersum but has a leaf nerve with a poorly differentiated ven-
tral epidermal layer of cells, and thickened longitudinal lamina cell walls, and is a
much smaller plant.

5. Additional specimens seen

Germany: Baden-Württemberg, Pfullingen, Wackerstein, F. HEGELMAIER, July 11, 1875, as
Dicranum muehlenbeckii (in S) 820m alt., T. ENGELMARK, Sept. 3, 1979 (in S). — Baden-
Württemberg, Sigmaringen, Oberschmeien, ca 700 m alt., T. ENGELMARK, Sept. 3, 1979 (in S).
— Baden-Württemberg, Schwäbische Alb, 7522 NO: Hohenwittlingen bei Bad Urach, unter-
halb der Ruine, W-exp. Steilhang mit Buchenwald, offener Felskopf auf Humus über Kalk,
halbschattiger Standort, Weißjura, 600 m, M. Sauer, 12. 03. 1995, Nr. MS95022, as Dicranum
muehlenbeckii? (Duplum in S).

Russia: Minusinsk, Kusnetski Alatau, ad fl. Nemir, E. SvEREFE, July 1886, as Dicranum mueh-

lenbeckü (in S).

8 STUTTGARTER BEITRÄGE ZUR NATURKUNDE Ser. A, Nr. 592

Mongolia: Urga, in monte Bogdo-ola, il silva, V. SMirNov, 1912, nr. 1395, as Dicranum sco-
parium (in S).

Iran: Prov. Mazandaran, Kudjur, between Kindj and Dasht-e Nazir, 800-1200 m alt, K. H.
RECHINGER, Aug. 1948, as Dicranum muehlenbecku (in S).

6. Acknowledgements

I am very grateful to TARANEH SJÖSTRÖM (Stockholm) for help with the illustrations, to
Nits Lunpevist (Stockholm) for help with the latin description, to the curator of the New
York Botanical Garden (NY) for loan of specimens, to MICHAEL SAUER (Reutlingen) for val-
uable discussions and help with the manuscript, and to CHRISTOPH HÄUSER (Stuttgart) for
proof-reading.

7. References

EGGLER, M. (1916): Beiträge zur Laub-, Torf- und Lebermoosflora von Württemberg. — Jh.

Ver. vaterl. Naturk. Württ. 72: 121-196; Stuttgart.
— (1926): Weitere Beiträge zur Laub- und Lebermoosflora von Württemberg. — Jh. Ver.

vaterl. Naturk. Württ. 82: 52-63; Stuttgart.

FROEHLICH, J. (1950): Bryophyten aus Iran. (Rechingeri iter iranicum secundum No. 9.) —
Annln naturhist. Mus. Wien (Botanik) 57: 37-41; Wien.

NEBEL, M. & G. Puiippr (eds.) (1999): Die Moose Baden-Württembergs. [In press]

SAUER, M. (in press): Dicranaceae. — /n: NEBEL, M. & G. PHıLıppi (eds.) : Die Moose Baden-
Württembergs.

Author’s address:

THOR-BJORN ENGELMARK, Swedish Museum of Natural History, Department of Crypto-
gamic Botany, Box 50007, S-104 05 Stockholm, Sweden.

ISSN 0341-0145

Schriftleitung: Dr. Wolfgang Seeger, Rosenstein 1, D-70191 Stuttgart
Gesamtherstellung: Gulde-Druck GmbH, D-72072 Tübingen

HW