Radula australiana K.Yamada Journal of the Hattori Botanical Laboratory 51: 323. 1982.

Renner, Matt A. M., Devos, Nicolas, Patino, Jairo, Brown, Elizabeth A., Orme, Andrew, Elgey, Michael, Wilson, Trevor C., Gray, Lindsey J. & Konrat, Matt J. von, 2013, Integrative taxonomy resolves the cryptic and pseudo-cryptic Radula buccinifera complex (Porellales, Jungermanniopsida), including two reinstated and five new species, PhytoKeys 27, pp. 1-113 : 22-26

Radula australiana K.Yamada Journal of the Hattori Botanical Laboratory 51: 323. 1982. Figs 8 -10

Type.

Australia: New South Wales: Merrits Creek 3 km east of Mt. Kosciuszko, 1870 m, 9 Feb 1978, H. Streimann 5358A (holotype: NICH, isotype: CANB!).

Description.

Forming pure turfs or mats of shoots, dark brown in herbarium; shoot systems regularly pinnately branched, with additional pseudodichotomous branching in female plants due to production of pairs of subfloral innovations below gynoecia; dimorphic, primary shoots 1.5-1.8 mm wide and up to 40 mm long, secondary shoots smaller in stature than parent shoot, 0.8-1.0 mm wide, and either apparently terminating growth after 4 to 7 leaf pairs, or producing reproductive structures and, in female plants, continuing vegetative growth; older shoot sectors retaining leaf-lobes.

Stems 120-160 µm diameter, with cortical cells in a single tier of 23-29 rows, cortical cell walls yellow-brown pigmented, external free cortical cell wall continuously thickened, radial longitudinal cortical walls thin or slightly thickened, inner tangential walls thickened; medulla cells in 23-45 rows, medulla cell walls faintly yellow-pigmented, thin walled, small triangular trigones, medial walls unthickened. Cortical cells on dorsal stem surface arranged in straight longitudinal rows on young and mature shoot sectors. Leaf insertion reaching dorsal stem mid-line, leaving no dorsal cortical cell rows leaf-free; leaf insertion not attaining the ventral stem mid-line, leaving two ventral cortical cell rows leaf-free. Leaf lobes rotund, 475-920 µm long by 400-780 μm wide, contiguous, not falcate, acroscopic base not sharply deflexed away from stem, weakly concave, not or weakly interlocking over the dorsal stem surface, stem visible between leaf lobes in dorsal view; margins entire or crenulated, not repand, the interior lobe margin shallowly ampliate, reaching the opposite stem margin, antical and exterior margins more or less continuously curved, postical margin shallowly curved or straight; angle between postical lobe margin and keel 140-180°. Lobules quadrate on leading shoots, one sixth to one quarter the lobe area, 330-605 µm long by 370-595 μm wide; keel straight to shallowly curved, angle between keel and stem 100-135°, keel turning through up to 30°, keel apex and postical lobe margin flush; interior lobule margin free for one quarter to one third its length, free portion ampliate, extending half way across the ventral stem surface or more; acroscopic margin S-shaped to straight, apical portion slightly inclined toward stem or perpendicular to it; apex obtuse but usually weakly apiculate; free exterior margin straight, margins plane, entire; lobe-lobule junction level with or slightly postical to the acroscopic end of stem insertion; attached to stem along 0.66-0.75 of the interior margin, stem insertion gently curved, not revolute; lobule apex bearing a single papilla, another two papilla situated on the interior lobule margin above the stem insertion. Leaf lobe cells rounded-oblong, not arranged in rows, unequally sized, 13-35 µm long by 11-21 μm wide, thin-walled with small triangular trigones, medial wall thickenings absent; cells of lobe margin smaller than those of leaf middle, quadrate to rectangular, 11-18 µm long by 9-13 µm wide, interior walls moderately and continuously thickened, exterior wall moderately and differentially thickened at mid-wall, forming a conspicuous bulge and imparting a crenulate appearance to lobe margin; leaf lobe cell surface unornamented, smooth. Oil-bodies 2 or 3, light brown, granular, internally homogeneous, filling the cell lumen. Asexual reproduction absent. Dioicous. Androecia on branches that usually terminate after production of 4 or 5 pairs of antheridial bracts, but rarely branches indeterminate, bearing ∞ pairs of antheridial bracts; lobules epistatic, keel deeply curved, bucket-like, free apical portion triangular, apex acute, interior margin ampliate, covering ventral stem surface, and imbricate with adjacent antheridial lobules; lobes rounded, not caducous, antheridia not seen. Gynoecia terminal on branch shoots, subtended by two or three subfloral innovations that are full-sized and again fertile; archegonia 125-150 µm tall, archegonia neck five cell columns, 10 per gynoecium on a small disc of tissue, encompassed by a low protoperianth; female bracts in one pair, symmetrical, tightly imbricate, elliptic-obovate, weakly falcate, lobe 690-770 μm long by 430-535 μm wide, margins crenulate; lobules rectangular, one half to two thirds the lobe area, apex obtuse, keel straight to arched, margins crenulate; bract insertion lines interlocking dorsally and ventrally, insertion equitant. Perianths 4200-4700 µm long and 1050-1200 µm wide at mouth, mouth entire to irregular, parallel sided for upper two thirds, widening to flask shaped, faint bulb in basal third, broadest in middle of this bulb, 1200-1350 µm wide, then tapering to base. Perianth walls unistratose above, with bistratose bands extending up to half way up perianth, increasing in width toward base, becoming confluent, basal perianth walls progressively increasing in thickness, 2-3-stratose. Long stem perigynium present, 5-6 stratose, cell walls heavily thickened and brown-pigmented. Calyptral perigynium present, base of calyptra 2-4 stratose at base, strata progressively lost, unistratose above, unfertilised archegonia elevated on surface of calyptra.

Etymology.

Australian.

Distribution and ecology.

Radula australiana occurs on mainland Australia (NSW, ACT, VIC), and in Tasmania and New Zealand, usually well above treeline in alpine or subalpine shrublands, grasslands and tussocklands where it grows in association with seepages and running water over and around exposed bedrock and boulders on alpine bluffs, rock outcrops and rock piles. However, Radula australiana also inhabits rocky open sites within forest habitats, particularly in Australia where high altitude Eucalyptus forest occurs in the alpine zone, and on bluffs associated with watercourses in New Zealand montane beech forest. Radula australiana is primarily a lithophyte on a wide range of sedimentary, metamorphic, and igneous rocks including greywacke and schist in New Zealand, and granite and basalt in Australia. Microsites occupied by Radula australiana are typically sheltered and shaded, such as the back walls of recesses in rock bluffs, crevices, between boulders within ephemeral streambeds. Radula australiana may also occur in bryophyte turfs on soil, usually in the shade of surrounding woody vegetation or rock. It shares all of these habitats with Radula helix , Herzogobryum teres , Nothogymnomitrion erosum , Cheilolejeunea mimosa , and Andreaea spp.

Variation.

Individuals vary in branching density, New Zealand plants are typically densely branched, and this also occurs in Australia. Openly branched individuals typically have larger shoots and correspondingly larger lobules that produce more pronounced acuminate lobule apices. These differences may be associated with both patch age and microsite. Shoots colonizing naked rock are always openly branched. Those growing in bryophyte turfs on soil are often closely branched.

Recognition.

One of the first clues to the identity comes from the habitat and microhabitat occupied by Radula australiana , as it is one of the few Australasian Radula species that inhabits subalpine and alpine areas, frequently in association with exposed rock. Among alpine species it is one of two having brown pigments, the other being Radula demissa M.A.M.Renner. Despite the considerable morphological disparity between them, three unrelated species have been confused with Radula australiana . Radula aneurismalis is yellow-green or orange-green, has a single botryoidal, light brown oil-body per cell, possesses microphyllous branches, has a distinct narrowly inflated lobule carinal region that extends the length of the keel, produces androecia on short spike-like lateral branches that may be determinate, and the perianths lack a stem perigynium. In contrast Radula australiana is brown-green, has two or three granular, brown oil-bodies per cell, does not produce microphyllous branches, though lateral branches may be smaller in stature than primary shoots, has a broadly inflated carinal region, produces androecia on long branches and on primary axes, and has perianths with a long stem perigynium.

Radula helix is almost as different from Radula australiana as is Radula aneurismalis . Radula helix is yellow-green, has 3-5 smooth, hyaline, oil-bodies per cell, is paroicous, with androecia immediately below gynoecia, and the perianth lacks a stem perigynium. In contrast, Radula australiana is brown-green, has 2-3 granular, brown oil-bodies per cell, is dioicous, and the perianth has a stem-perigynium.

Radula acutiloba is similar in its lobules having an acuminate tip on main shoots, and on this basis Radula australiana was confused with Radula acutiloba in Devos et al. (2011) by the first author of this contribution who followed herbarium determinations. Though sharing similar lobule shapes, and some phenetic similarity, Radula australiana differs from Radula acutiloba in lacking subdiscoidal gemmae on the leaf lobe margin, by its brown-green not yellow-green colour, by the presence of two or three light to tan-brown oil bodies in each leaf lobe cell, lack of secondary thickening on cell walls in the stem medulla, and by its occurrence in subalpine and alpine habitats. In all populations of Radula acutiloba examined, subdiscoidal gemmae have been present on the leaf lobe margin. This feature alone is sufficient to discriminate between these two species.

Two related species, also members of the Radula buccinifera complex, occasionally co-occur with Radula australiana and may be confused with it. In Australia, Radula buccinifera is typically a forest inhabitant, but at some sites in Victoria and Tasmania where forest occurs over and among exposed granite boulders at high altitude, the ecological envelopes of Radula australiana and Radula buccinifera overlap, and they may co-occur. Morphological characters by which Radula australiana may be distinguished from Radula buccinifera are presented in the recognition section for Radula buccinifera .

In New Zealand, Radula demissa is typically a forest inhabitant, but has an alpine ecotype that, although it has not yet been found co-occurring with Radula australiana , occupies similar microhabitats. Morphological characters by which Radula australiana may be distinguished from Radula demissa are presented in the recognition section for Radula demissa . Radula australiana could be confused with Radula strangulata , for differences between these two species see the recognition section of Radula strangulata .

Specimens examined.

Australia: New South Wales: Southern Tablelands, Mount Kosciuszko National Park, Main Range track to Kosciuszko summit from Charlotte Pass, 36°27'01"S, 148°18'31"E, 1920 m, 26 Feb 2011, M.A.M. Renner 5114 & E.A. Brown, NSW893115; Southern Tablelands, Mount Kosciuszko National Park, Main Range track to Kosciuszko summit from Charlotte Pass, 36°27'01"S, 148°18'31"E, 1920 m, 26 Feb 2011, M.A.M. Renner 5115 & E.A. Brown,NSW893116; Southern Tablelands, Kosciuszko National Park, unnamed hill north of Daners Creek and Pipers Creek junction, 36°22'35"S, 148°27'37"E, 1600 m, 27 Feb 2011, M.A.M. Renner 5127 & E.A. Brown, NSW909241; Southern Tablelands, Kosciuszko National Park, unnamed hill north of Daners Creek and Pipers Creek junction, 36°22'35"S, 148°27'37"E, 1600 m, 27 Feb 2011, M.A.M. Renner 5129 & E.A. Brown, NSW909251; Southern Tablelands, Kosciuszko National Park, unnamed hill north of Daners Creek and Pipers Creek junction, 36°22'18"S, 148°27'34"E, 1720 m, 27 Feb 2011, M.A.M. Renner 5130 & E.A. Brown, NSW909252;

Australian Capital Territory: 36 km SSW of Capital Hill, Canberra, Tower 2.5 km north of Orroral Tracking Station, 35°37'S, 148°59'E, 1340 m, 22 Oct 1987, H. Streimann 38961, HO312250; New South Wales: Southern Tablelands, Kosciuszko National Park, The Rams Head Range, Merrits Spur, 36°29'S, 148°18'E, 1770 m, 13 Jan 2002, J.A. Curnow 5638, CANB636815; J.A. Curnow 5635, CANB636812; Kosciuszko National Park, 7.5 km NE of Mt Kosciuszko, Blue Lake, 36°24'S, 148°19'E, 2020 m, 3 Mar 1991, H. Streimann 47093, CANB9107074; Snowy Mountains, The Rams Head Range, Charlotte Pass, 36°26'S, 148°19'E, 1830 m, 3 Dec 1965, L.G. Adams 1545, CANB162786, CHR265733;

Victoria: Mt McKay, Alpine National Park, 16 km SSE of Mount Beauty, 36°52'S, 147°14'E, 1840 m, 18 Feb 1994, H. Streimann 53505, CANB9403675; H.Streimann 53469a, MEL2300398; Snowfields, Mount Buller, 37°07'S, 146°25'E, 1665 m, 9 March 1953, J.H. Willis s.n., MEL1037780, as Radula physoloba ; Mt Buller area, 37 km ESE of Mansfield, 37°09'S, 146°26'E, 1600 m, 30 December 1992, H.Streimann 50758, CANB9219759; Snowfields, Alpine National Park, Cope Creek, 36°54'S, 147°14'E, 1650 m, 5 March 1993, E.A. Brown 93/72 & K.L. McClay,NSW272960; Snowfields, Baw Baw National Park, Alpine Walking Track, c. 100 m north of Mount Erica car park, 37°53'S, 146°21'S, 1100 m, 9 March 1993, E.A. Brown 93/145 & K.L. McClay, NSW273911; Charlotte Pass, Ramshead Range, Snowy Mountains, c. 6,000 ft, 3 December 1965, L.G. Adams 1545, FH00284638; Snowfields, Mount Buller, summit, 37°08'41"S, 146°25'29"E, 1795 m, 28 Feb 2011, M.A.M. Renner 5133 & E.A. Brown, NSW875860; Snowfields, Mount Buller, summit, 37°08'41"S, 146°25'29"E, 1795 m, 28 Feb 2011, M.A.M. Renner 5135 & E.A. Brown, NSW875862; Snowfields, Mount Buffalo National Park, Slope immediately below carpark at The Horn, 36°46'33"S, 146°45'51"E, 1614 m, 01 Mar 2011, M.A.M. Renner 5142 & E.A. Brown, NSW875928; Snowfields, Mount Buffalo National Park, Mahomets Tomb outcrop, 36°45'12 S, 146°47'41"E, 1570 m, 01 Mar 2011, M.A.M. Renner 5150 & E.A. Brown, NSW875947; Snowfields, Alpine National Park, Mount Loch, summit, 36°57'30"S, 147°09'19"E, 1858 m, 2 Mar 2011, M.A.M. Renner 5162 & E.A. Brown, NSW875951; East Gippsland, Errinundra National Park, Mount Ellery, track to summit from the Ferntree track, 37°23'38"S, 148°46'21"E, 1080 m, 4 Mar 2011, M.A.M. Renner 5204 & E.A. Brown, NSW909259;

Tasmania: Ben Lomond, Hamilton Crags, 42°32'S, 147°41'E, 1460 m, 5 Jan 1992, A. Moscal 22365, HO301803; Mt. Field, Mt. Field East, 42°40'S, 146°39'E, 1155 m, 12 Apr 1992, A. Moscal 23324, HO132882; Mt. Field, Naturalist Peak, 42°60'S, 146°31'E, 1390 m, 10 Mar 1992, A. Moscal 23011, HO525812;

New Zealand: South Island: Nelson, Kahurangi National Park, Cobb Valley, between Cobb Lake and Round Lake, 41°03'23"S, 172°30'08"E, 1150 m, 19 Feb 2012, M.A.M. Renner 6230, NSW895690; Nelson, Kahurangi National Park, Cobb Valley, Round Lake cirque, 41°03'21"S, 172°29'53"E, 1290 m, 19 Feb 2012, M.A.M. Renner 6239, NSW896176; Hawkdon Ecological Region, Arthurs Pass Ecological District, Arthurs Pass, Temple Basin, 42°55'S, 171°35'E, 1440 m, 1 Apr 2001, M.A.M. Renner 01/114, AK280485; Canterbury Land District, Ohau, South Huxley Valley, 44°4'S, 169°42'E, 1200 m, 9 Nov 1996, D. Glenny 6567, CHR559967; Canterbury Land District, Ohau, South Huxley Valley, 44°02'S, 169°46'E, 1530 m, 9 Nov 1996, D. Glenny 6575, CHR559976; South Westland, northern Olivine Range, north of Dragon, 44°9'S, 168°37'E, 1250 m, 14 Feb 1995, D. Glenny 5769b, WELT-H0010890;Otago Land District, Remarkables Range, head of Wye Creek, 45°5'S, 168°50'E, 1760 m, 28 Dec 1998, D. Glenny 7627, CHR529388; East Dome, Garvie Range, 4500 ft, 5 Dec 1981, J. Child, CHR427233; Earnslaw, N ridge, 24 Oct 1973, J. Child, CHR427228; Fiordland, Fiordland National Park, Cozette Burn, 1080 m, 10 Apr 2002, M.A.M. Renner s.n., CHR583911; South Westland, Haast Pass, western slopes of Mount Armstrong above Brewster Hut, 44°05'22"S, 169°24'55"E, 1530 m, 16 Feb 2012, M.A.M. Renner 6142, NSW895444; ibid, 44°05'27"S, 169°24'56"E, 1580 m, 16 Feb 2012, M.A.M. Renner 6148, NSW895456.

Figures

Figure 8. Radula australiana line drawings 1: A Five lobules from primary shoots showing size and shape variation, with broadly ampliate free interior margin and drawn-out apex B Five lobules from secondary shoots showing size and shape variation C Cellular detail of interior free lobule margin D Ventral shoot E Dorsal shoot F Cellular detail of lobule apex G Transverse stem section from primary shoot. Scale bars: A-B: 240 µm, D-E: 600 µm, C, F: 60 µm, G: 40 µm. All from NSW 273911.

Figure 10. Radula australiana pictures. A Ventral view of shoot B Immature perianth. C-E Ventral view of shoots and lobules F Gynoecium G Androecium H Transverse sections of stems from primary shoot I Leaf-lobe marginal cells. A from CHR 559976, all others from NSW 875862.