A Preliminary Study of the Genus Radula from Queensland, Australia
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Journ. Hattori Bot. Lab. No. 62,' 191-200 (June 1987) A PRELIMINARY STUDY OF THE GENUS RADULA FROM QUEENSLAND, AUSTRALIA KOHSAKU Y AMADA 1 Twenty-two species of the genus Radula have been recorded in the literature from Australia (induding Tasmania) by Hampe (1838), Stephani (1884, 1889, 1910), Castle (1963, 1964, 1967), Yamada (1979, 1982, 1984), and Windolf (1985). Eleven are en demic to Australia: Radula australiana, R . compacta, R. hicksiae, R. jovetiana, R. novae-hollandiae, R. ocellata, R. patens, R. pulchella, R. rathokowskiana, R. tasmanica, and R. wattsiana. However, most of them are known only in the southeastern part of Australia, such as New South Wales, and Tasmania. The Radula flora of Queensland has not been studied adequately, even though in recent years Yamada (1984) has re ported 9 species (induding 3 new species). Recently I had an opportunity to study many collections of Radula from Que ensland made by Dr. I. G. Stone, Dr. H. Streimann, Dr. B. M. Thiers, and Dr. M. 1. Hicks. In the present paper, I recognize 18 species, of which 2 species are new to science. I wish to express my sincere thanks to Dr. G. A. M. Se ott of Monash University (Aus tralia), Dr. M. L. Hicks of Appalachian State University (North Carolina), Dr. H. Streimann of Canberra Botanic Gardens (Canberra), and Dr. B. M. Thiers of The New York Botanical Garden (New York), for the loan of Radula specimens. Thanks are also due to Dr. S. Hattori of the Hattori Botanical Laboratory for his critical advice, and to Dr. A. J. Sharp of the University of Tennessee, for his kind help with the English of the manuscript. Subgenus Odontoradula Yamada Key to the species 1. Leaf-lobes with vitta . .......... .. ..... .. .. .... ... ....... 2. R. ocellata 1. Leaf-lobes without vitta ................................ ................... 2 2. Leaf-lobes with subacute apices, the margins of apical portion entire; walls of leaf- cells without trigones; female bracts of two pairs ...... ... 1. R. novae-hollandiae 2. Leaf-lobes with acute apices, the margins of apical portion with 1-3 acute teeth; walls of leaf-ceIls with medium-sized trigones; female bracts of one pair . .... 3. R. queenslandica 1. Radula novae-hollandiae Hampe In Lehmann, Nov. Min. Cogn. Strip. Pugillus 7: 24 (1838). Specim. exam.: Werwah, 80 m, J. Windolf813 (hb J. Windolf, hb K. Yamada); Mt. Bethongabel, 900 m, B. M. Thiers 1238 (NV); trail to Elebana Falls, 500 m, B. M. Thiers 1110 (NV); trail to Lyre Bird Lookout, 1000 m, B. M. Thiers 1194 (NV); track to Mt. Bethongabel, 900 m, B. M. Thiers & R. H. 1 941-47 Funaeyama, Seta-cho, Ise-shi 516, Mie-ken; also the Hattori Botanical Laboratory, Obi, Nichinan-shi, Miyazaki-ken 889-25. 192 Journ. Hattori Bot. Lab. No. 62 1 987 Hailing 2786 (AD, NY); Mt. Cool urn, 60-80 m, B. M. Thiers 2851 (AD, NY); Mt. Lewis SW of Mossman, M. L. Hicks 11134, 11394 (BOON, NICH); Mchugh Bridge along Palmerston Highway W of Innisfail, M. L. Hicks 10973 (BOON, NICH); Mt. Bartle Frere, M. L. Hicks 11031,11032,11228 (BOON, NICH); Devil's Thumb W of Mossman, 1150 m, M. L. Hicks 11274 (BOON, NICH); Mt. Spurgeon W of Mossman, M. L. Hicks 11101 (BOON, NI CH). Distr.: Endemic to Australia. This species has not known from Queensland until recently. Yamada (1984) and Windolf (1985) reported this species from Queensland where it seems to be one of the commonest species. 2. Radula ocellata Yamada J. Hattori Bot. Lab. 45 : 209 (1979). Specim. exam.: Mt. Lewis, 1. G. Stone (MUCV 6093); Malanda Falls along N of Johnstone River, 750 m, B. M. Thiers & R. E. Halling 2180 (AD, NY); Mt. Bellenden Ker, 1500 m, B. M. Thiers & R. E. Halling 2452 (AD, NY); Mt. Lewis, 1000 m, B. M. Thiers & R . E. Halling 2620 (AD, NY); Mt. Windsor Tableland NW of Mossman, M. L. Hicks 11218, 11224, 11226 (BOON, NICH); Bartle Frere, M. L. Hicks 11236 (BOON, NICH); Mt. Spurgeon W of Mossman, M. L. Hicks 11103 (BOON, NICH). Distr.: Endemic to Australia. This species seems to be common in Queensland. 3. Radula queenslandica Yamada, sp. novo (Fig. 1) Planta minuta, olivacea; caulis 4-7 mm longus, irregulariter pinnatim parviramosus; lobi foliorum caulinorum laxe vel moderate imbricati, in piano ovati vel faicati-ovati, apice ± incufvo, sparsim 1- 3 dentato, dentibus acutis vel subacutis, parietibus cellularum medianae tenuibus, trigonis mediocribus; lobuli oblique patuli, subquadrati (vel raro ovati), apice obtuso, basi caulem haud tegente, carina leviter arcuata vel subrecta; dioica (androecia haud visa) ; gynoecia in caulibus terminalia; perianthia longa, plano-cylindrica, ore subtruncato. Plants small, olive-green in herb. Stem 4-7 mm long, ca. 0.05 mm in diam., with leaves 1.0-1.3 mm wide, irregularly pinnately branched, ordinary branches few, 2- 3 mm long, ca. 0.04 mm in diam., with leaves 0.7-0.9 mm wide; stem 4 cells thick, cortical cells as large as medullary cells, both cells thin-walled with medium-sized trigones, subhyaline. Leaf-lobes widely spreading, loosely to moderately imbricate, concave, ovate to falcate-ovate, 0.5- 0.65 mm long, 0.4-0.5 mm wide, apices with 1- 3 teeth, teeth acute to subacute, ± incurved, basal margins slightly arched, not auriculate, covering the stem 1/4-1/3 of the stem-width, insertions substraight; marginal cells 11-15 x 6-9 .urn, thin-walled with medium-sized trigones, median cells 15- 17(- 21) x 12-15 .urn, thin-walled with somewhat large trigones, basal cells 12- 15 x 6- 8 .urn; cuticle smooth; leaf-lobules obliquely spreading, subquadrate (or rarely ovate), ca. 1/2 (or less) the lobe-length, 0.18-0.2 mm long, 0.13-0.18 mm wide, apices obtuse, not elongate, abaxial margins slightly arched or substraight, not decurrent, adaxial margins substraight, bases not covering the stem, insertions substraight, carinal regions widely inflated; rhizoid-initial area convex, rhizoids rarely seen, pale brown; keel spreading at angles of 50° with the stem, 0.2- 0.3 mm long, slightly arched or substraight, not decurrent, sinuses wide. Dioecious (androecium not seen). Gynoecium terminal on stem, with two subfloral in novations; bracts in one pair; bract-lobe oblong-ovate with irregularly 4-8-toothed apex, bract-lobule oblong, with irregularly 2- 3-toothed apex and strongly sinuate keel; perianth long, flat-cylindric, ca. 2 mm long, 0.6 mm wide at mouth, mouth subtruncate. Type: Queensland: Mt. Bartle Frere, June 2,1982, I. G. Stone n.s. - holotype (MUCV 6004; dupl. in NICH). K. Y AMADA: The genus Radula from Queensland, Australia 193 FIG. 1. Radula queenslandica Yamada. a. Portion of stem with perianth, ventral view, x 26. b. Portion of stem, dorsal view, x 26. c. Cross-section of stem, x 533. d-f Cells of lobe of stem-leaf, d from margin, e from middle, f from base, aB x 533. g. Apical portion of leaf-lobule, x 533. h, i. Female bracts, x 26. Drawn from holotype. The diagnostic characters of this species are (I) the stem 4 cells in thickness, (2) the widely spreading, loosely to moderately imbricate, ovate to falcate-ovate leaf-lobes with 1-3 teeth at the apices (teeth subacute to acute), (3) the thin-walled median cells of leaf-lobes with medium-sized trigones, (4) the subquadrate (or rarely ovate) leaf lobules with obtuse apices and slightly arched (or substraight), not decurrent keels, (5) the leaf-Iobules not covering the stem at the base, (6) the gynoecium terminal on the stem, with two subfloral innovations and one pair of bracts, and (7) the long, flat cylindric perianth with a subtruncate mouth. The present new species is closely related to Radula fissifolia Steph. known only 194 Journ. Hattori Bot. Lab. No. 62 1 987 from New Caledonia. However, the latter is d ifferent from R. queenslandica in (I) the thin-walled leaf-cells with large trigones, (2) the ovate leaf-lobes with usually incurved apices, (3) the female bract-Iobules with entire margins, and (4) the mouth of the perianth with long, sharp-pointed teeth. The present new species is also related to R. dentifolia Grolle known only from New Zealand, but the latter is different from the new species in having the two pairs of female bracts and the female bract-Iobes and bract-Iobules with entire margins except short pointed apices. Subgenus Radula Key to the species 1. Plants with amentulose branches................... ... .. ......... ............ 2 1. Plants without amentulose branches. .. 3 2. Leaf-10bules with wholly and strongly inflated carina! regions, keels strongly arched; amentulose branches usually strongly incurved at apices . .... .. 18. R. thiersiae 2. Leaf-lobules with slightly inflated carinal regions, keels substraight to slightly arched; amentulose branches not incurved at apices .... ... .. .... ...... 5. R. hicksiae 3. Gemmae present .............. ...... ...... ........... .. .. .... ........... 4 3. Gemmae absent. .. 5 4. Plants usually growing on living leaves of trees or on fronds of ferns; gemmae oc curring on ventral margins of leaf-lobes ; apices of leaf-Iobules usually strongly turning away from the stem ..... .. ................ .......... ....... 11 . R. nymanii 4. Pl ants growing on bark of trees; gemmae occurring on margins of leaf-lobes; apices of leaf-Iobu les not turning away from the stem . .. .... .. ..... 4. R. acuti/oba 5. Apices of leaf-lobules usually strongly or weakly turning away from the stem .. .... 6 5. Apices of leaf-Iobules not turning away from the stem. .. 7 6. Stems densely branched; leaf-Iobules widely ovate (rarely subrhombic), apex always strongly turning away from the stem ..... ...... 15a. R. retro/lexa var. /auciloba 6. Stems few-branched ; leaf- Iobules almost subrhombic, apex parallel with, or only slightly turning away from, the stem .........................