Journ. Hallori BOI. Lab. No. 61: 269- 272 (Dec. 1986 )

A NEW ACROMASTIGUM-LIKE OF S. GRAY FROM BHUTAN

NAOFUMI KITAGAWA' AND RICLEF GROLLE2

ABSTRACT. Bazzania bhutanica sp. novo (Lepidoziaceae) with similarities to Acromasligum subg. Inaequilalera is described and figured from Bhutan. Furthermore, some critical characters of B. grijJilhiana (Steph. ) Mizut., which is the type of the recently proposed monotypic genus Dendrobazzania Schust. et Schof., are discussed.

Bazzania bhutanica Sp. novo (Fig. 1) Species insignis, a speciebus Bazzaniae nobis notis differt habitu Acromasligi (su bgen. Inaequilalera); plantis parvis, prostratis; foliis recte patulis, asymmetrice oblongo-ovatis vel -llInceolatis, bilobatis, vi ttatis, margine crenulato; amphigastriis saepe profunde trilobatis; cuticula valde aspera, saepe verruculosa. sterile, small, pale oli ve-brown and faintly frosty, rather rigid, in thin, loosely interwoven mats; shoots prostrate, 1.2 - 2.0 mm wide; stems up to 20 mm long, 100 - 160 pm thick, su bterete, often covered with thin mucilaginous substance; cortical cells in 14 - 16 rows, strongly thick-walled, long rectangular to linear in surface view, mostly 40 - 65 x 15 - 20 pm, tangentially elongate in cross-section; medullary cells in many rows, as large as the cortical ones, thick-walled - thus, no hyaloderm is defined; terminal branching infrequent, exclusively of the Frullania type, with pseudodichotomies at an angle of 75 - 90 degrees; intercalary branches rather frequen t, arising in underleafaxils, becoming mostly flagelliform but occasionally developing into ordinary leafy shoot; flagelliform branches up to 5.5 mm long, bearing bilobed, scale-like leaves in 3 rows. Rhizoids occurring on flagelliform branches, arising from the base of their leaves, colorless. Leaves fragile, often caducous and variously broken along middle lamellae of cells, contiguous to weakly imbricate, quite obliquely inserted by a rather short, straight line, spreading at nearly right angles, lying in a single plane or slightly secund dorsally when moist, oblong-ovate to -lanceolate, somewhat asymmetrical, 650 - 1000 pm long, 240 - 400 pm wide, deeply (1 /4 - 1/3) bilobed or rarely trilobed; sinuses narrow, mostly V-shaped; both lobes narrowly triangular to lanceolate, 6 - 7 cells wide at base, subacute and tipped with a single cell or a row of 2 - 4 cell s at apex; margins remotely and vaguely denticulate or merely edged, distinctly crenulate throughout from projecting cells; dorsal base slightly rounded and not arching beyond the middle line of axis; ventral base simple, not connate with underleaf bases. Vittae developed but not clearly defined because of adjacent transitional cells, 5 - 7 cells wide in the basal portion of leaves; leaf cells rather opaque, various-sized, those of lobes (in the median portion) 24 - 32 x 16 - 24 pm, of margins 15 - 25 pm, of median vittae 25 - 48 x 20 - 32pm, of basal vittae 28 - 55 x 24 - 30 pm; walls evenly thickened and with indistinct trigones; cuticle strongly asperous and often coarsely verruculose (basally striolate-verruculose). Underleaves shortly distant to contiguous, transversely inserted, weakly patent but not reflexed, subquadrate

I Biological Laboratory, Nara University of Education, Takabatake-cho, Nara 630; also the Hattori Botanical Laboratory, Obi, Nichinan-shi, Miyazaki-ken 889-25, Japan. 2 Friedrich-Schiller-Universi tiit, Sektion Biologie, WB Phytotaxonomie, 69 Jena, DDR. 270 Journ. Hattori Bot. Lab. No. 61 198 6 N. KITAGAWA & R. GROLLE: A new Acromastigum-like Ba==ania from Bhutan 271 in outline, 230 - 350 /lm long, 220 - 400 /lm wide, deeply (ca. 2/3) 2 - 3-lobed with lateral marginal teeth sometimes large enough to simulate smalle r lobes; lobes divergent, usually with a few marginal teeth or blunt edges, acute to acuminate at apex; bases more or less dilated but not auriculate. Cells of underleaves similar to those of leaves. Specim. exam. BHUTAN. Samchi District: ravine at Buduni W ofSamchi, 26 0 54 'N, 89' 03'E, subtropical forest, on crumbling rock, D. G. Long 10532 (holotype in E; isotypes in KYO, NIC H, JE). Bazzania bhutanica is very characteristic in the Acromastigum-Iike appearance. The species shows such a long series of criteria which prevail in the subgenus lnaequilatera of the latter genus: (I) plants small and growing prostrate in a thin, depressed mat; (2) leaves asymmetrically oblong-ovate to -lanceolate, deeply bilobed and very widely spreading in nearly a single plane; (3) their margins denticulate and crenulate from projecting cells; (4) underleaves mostly trilobed (but this is often obscured by large lateral teeth); (5) leaf cells various-sized and forming a vitta; (6) cell walls evenly thicknened and with indistinct trigones; (7) cuticle of leaf cells strongly asperous and often verruculose. This ensemble of similarities is, however, quite superficial, and the species is sharply different from Acromastigum in the terminal branching which is exclusively of the Frullania type (never of the Acromastigum type) as well as in the stem anatomy in which the cortical cells are in many rows and hardly differentiated from the medullary ones (thus, not forming a hyaloderm). In Acromastigum, with a few exceptions, the cortical cells in leafy shoots are constantly in 7 rows, much larger than the medullary ones and forming a distinct hyaloderm. Simple relationships are there recognized betwe~n the width of merophytes in stems and the number of divisions (lobes) in lateral organs (leaves and underleaves). Of seven cortical cells seen in cross section the four dorsilateral ones are larger and the three ventral ones are smaller. The former belong to the two lateral merophytes and the latter to the ventral one, and the leaves inserted on two cortical cells are bilobed while the underleaves on three cells are trilobed - each division of the lateral organs corresponds with a cortical cell of the stem. In Bazzania with several hundreds of species, the merophytes are diverse in width but never 2 - 3 cells wide as in Acromastigum. In Bazzania bhutanica the cortex of ventral merophytes is usually 5 cells wide in stems with trilobed underleaves and 4 cells wide in stems with bilobed underleaves. According to Schuster and Schofield (\ 982) the subfamily Bazzanioideae Rodway of the-Lepidoziaceae Limpr. includes four genera: Bazzania S. Gray, Dendrobazzania Schust. et Schof., Acromastigum Evans and Mastigopelma Mitt., which are properly keyed out there. In Bazzania and Dendrobazzania the terminal branching is exclusively of the Frullania type (the branch replaces the ventral half of a leaf). Acromastigum

FIG. I. Bazzania bhutanica Kitag. et Grolle. I. Part of shoot, ventral view, x 20. 2. Do., dorsal view, x 20. 3.4. Cells of leaf lobes, x 200. 5. Cells of underleaf lobe, x 200. 6--11. Underleaves, x 50. 12. Part of shoot, ventral view, x 30. 13- 15. Leaves, x 40. 16. Cells of leaf margin and adjacent vitta, x 200. 17. Cross section of stem, x 320. 18. Cells of leaf margin and vitta, x 320. All drawn from type. 272 Joum. Hattori Bot. Lab. No. 61 I 986 possesses terminal branching of both the Frullania type and the Acromastigum type (the branch replaces a half of an under leaf); the branch of the former type is developed into the lateral leafy shoots and that of the latter into the ventral flagelliform branches. Masligopelma is devoid of any type of terminal branching. So, the present new species bearing the terminal branching of the Frullania type only is definitely placed in the genus Bazzania. In this connection some notes should be referred to Dendrobazzania which was recently described by Schuster and Schofield (1982) as a new genus for Bazzania grifJithiana (Steph.) Mizut. The generic description was made on the basis of material from British Columbia, Canada, which somewhat disagrees with the type material from the Himalayas. This monotypic genus was defined by the pinnate branching (the leading shoot remains apical dominance and the branches are limited in length often becoming flagelliform-microphyllous as in ) as well as by the absence of ventral flagelliform branches. The latter criterion is certainly inadequate to character­ ize the new genus, because the short ventral flagella are existing in type material of B. grifJithiana. Moreover, we have recently examined a critical specimen3 of Bazzania praerupta (Reinw. et at.) Trev. which seems to be a menace to the status of Dendrobazzania. In this specimen, the plants are rather stout attaining to a length of 40 mm and subpinnate with leading shoots well defined by apical dominance and with lateral branches rather frequent and of limited length (mostly less than 10 mm long), and the ventral flagelliform branches are depauperate (no more than 8 mm long and only 80 - 120 J.lm thick - very slender in contrast with leading stems which are 360 - 480 J.lm thick). These features suggest that the specimen apparently represents a form intermediate between B. praerupta and B. grifJithiana; the former is a species widely distributed in eastern Asia and showing a very wide range of variation. Thus, we agree with Mizutani (1967) who noted "This species (B. griffithiana) is very closely related to, and may possibly be a variety of, B. praerupta." Bazzania bhutanica and B. griffithiana, both originally described from Bhutan, are largely deviated in appearance from usual members of Bazzania but no essential discrepancy is found there to separate them into different genera. Such deviations may be due to a mere 'mimicry', the former to Acromastigum and the latter to Lepidozia.

We wish to acknowledge our deep gratitude to Or. O. G . Long (Edinburgh), who kindly posed his excellent collection of Bhutanese hepatics to the study of the junior author. We are very grateful also to Or. S. Haltori (Nichinan) for his kind advice.

REFERENCES

Mizutani, M. 1967. Studies of the Himalayan species of Bazzania. J. Hattori Bot. Lab. 30: 71- 90. Schuster, R. M. & W. B. Schofield, 1982. On Dendrobazzania. a new genus of Lepidoziaceae (). The Bryologist 85(2): 231 - 238.

3 Bhutan. Longte Chu nr Charikhachor Chorten nr Chendebi, W of Tongsa; on log, 2450 malt., D. G. Long 8098, in E, JE, K YO.