Leptospermum jingera (Myrtaceae - Leptospermoideae): A New Species From North-eastern Victoria

(A) Australian National Botanic Gardens, Centre for Plant Biodiversity Research, GPO Box 1777 Canberra, ACT 2601, Australia.

(B) Division of Botany and Zoology, Australian National University, Canberra, ACT 0200, Australia. Email: mike.crisp@anu.edu.au

Abstract

Leptospermum jingera, a new species from the Brumby Point area of the snowfields natural region of north-eastern Victoria, is described and illustrated. It is a highly restricted endemic most closely related to L. namadgiensis Lyne.

Introduction

Leptospermum was recently revised by Thompson (1989), who indicated that there was complex variation in L. brevipes F. Muell. One of the authors of this paper (AML) is currently examining the variation exhibited by L. brevipes across its range from north-eastern Victoria, through the Australian Capital Territory and eastern New South Wales to south-eastern Queensland. Examination of collections and observation in the field of several populations of L. brevipes from Victoria revealed that specimens from Brumby Point on the Nunniong Plateau in Alpine National Park (Cobberas-Tingaringy unit) previously ascribed to L. brevipes are distinct. It is proposed that this population represents a new species.

The opportunity is taken here to provide the species with a name for the forthcoming Flora of Victoria.

Description

Frutex 0.5-2 m altus. Cortex versus basem stratis multis papyraceis. Folia 6-10(-15) mm longa, 2-2.5(3.5) mm lata, anguste obovata vel elliptica, sericea, glabrata. Flores 6-10 mm diametro. Hypanthium 2.5-3 mm longum, 1.5-2 mm diametro, sericeum, pedicello 2-3.5 mm longo. Ovarium 3-5 loculare. Fructus deciduus, 2.5-3 mm longus, 2-3 mm diametro, loculicidalis, sericeus vel sparsim sericeus.

Shrub 0.5-2 m high. Bark in many papery layers towards base. Lamina 6-10 (-15) mm long, 2-2.5 (-3.5) mm wide, narrowly obovate to elliptic, silky, glabrescent. Flowers 6-10 mm in diameter. Hypanthium 2.5-3 mm long, 1.5-2 mm in diameter, silky, pedicel 2-3.5 mm long. Ovary 3-5 locular. Fruit deciduous, 2.5-3 mm long, 2-3 mm in diameter, loculicidal, silky to sparsely silky.

Typus: Victoria: Snowfields natural region: Alpine National Park, Nunniong Plateau, Brumby Point, c. 5 km along Brumby Point Track from its junction with Diggers Hole Track 37° 03' 30" S, 148° 03' 18" E, 11 Dec. 1994, A.M. Lyne 1524 (holotype: CBG 9409635; isotypes: BRI, K, MEL, NSW).

Shrub 0.5-2 m high. Bark firm on smaller stems, present in many papery layers towards base of plant. Branches silky when young, soon glabrescent, with a groove near base of petiole. Leaves narrowly obovate to elliptic, flat or incurving, base cuneate, apex acute, flat to incurved, not pungent, lamina 6-10(-15) mm long, 2-2.5(-3.5) mm wide, young leaves silky on both surfaces, becoming glabrous to reveal many dark oil dots, petiole c. 1 mm long. Flowers [Flowers 1] [Flowers 2] [Flowers 3] 6-10 mm in diameter, occurring singly or in pairs in leaf axils. Hypanthium 2.5-3 mm long, 1.5-2 mm in diameter, silky, the base constricting above a pedicel 2-3.5 mm long. Sepals 5, persisting on fruit, narrowly triangular, margins incurving (strongly so in dried material), c. 1 mm long, silky or occasionally glabrous on outer surface, puberulous on inner surface. Petals 5, circular, 3-4 mm long, white. Stamens 10-13, randomly inserted on rim, filaments glabrous, flaring at base. Style base shallowly inset into ovary summit, style without taper. Ovary apex shortly silky all over, 3-5 locular (often varying on same plant), with 8-16 ovules per loculus on a high placenta. Fruit hemispherical, 2.5-3 mm long, 2-3 mm in diameter, loculicidal splits developing below the hypanthium rim and extending c. half way towards base in older fruit, deciduous, silky to sparsely silky, lobed in cross section, the base rounded above a pedicel 2-3.5 mm long. Mature seeds c. 1.5 mm long with a coarsely reticulate pattern and often with rows of loose cells along the margins.

Main flowering period Dec. to Jan. as seen from dried specimens and field observations.

The illustration is here

Specimens Examined

Victoria - Snowfields natural region: In the vicinity of the end of the Brumby Point track, Nunniong Plateau, 37° 03' 15" S, 148° 04' 30" E, 29 Dec 1984, D.E. Albrecht 1363 (MEL 673915, Vic. Ref. Set); Above Reedy River Gorge - along water course near Brumby Point, 21 Jan 1971, A.C.B. Beauglehole 36370 & E.W. Finck (MEL 526832); Nunniong Plateau, along saddle running north ± 1 km east of end of Brumby Point track, 37° 03' 20" S, 148° 05' 00" E, 2 Jan 1987, M.G. Corrick 10163 (MEL 686286, NSW); Alpine National Park, Nunniong Plateau, Brumby Point, 37° 03' 16" S, 148° 04' 38" E, 25 Apr. 1993, A.M. Lyne 1189 & J. Lyne (CBG 9303364, BRI, MEL, NSW, PERTH); Alpine National Park, Nunniong Plateau, Brumby Point, 37° 03' 16" S, 148° 04' 38" E, 25 Apr. 1993, A.M. Lyne 1190-1194 & J. Lyne (CBG 9303365 - 9303369); Brumby Point, Nunniong Plateau, East Gippsland, 37° 03' 25" S, 148° 03' 40" E, 26 Feb 1982, N.G. Walsh 853 (MEL 628384).

Etymology

The specific epithet is an Aboriginal word meaning remote and mountainous bush-covered country or wild, rough country (see Ramson 1988: 335). It is a reference to the nature of the species' habitat.

Distribution

Highly localised and endemic to Victoria, Leptospermum jingera is known only from the Brumby Point area of the Nunniong Plateau in Alpine National Park (Cobberas-Tingaringy unit). The population appears to be distributed along c. 2 km of ridge-top from a point at 37° 03' 30" S, 148° 03' 18" E to a point at 37° 03' 11" S, 148° 04' 55" E. This area is located in the snowfields natural region of Conn (1992).

Habitat and ecology

Leptospermum jingera grows in shrubland and low woodland along a ridge-top of Ordovician sediments. Associated species include Banksia canei, Podolobium alpestre, Bossiaea foliosa, Monotoca rotundifolia, Eucalyptus glaucescens, E. kybeanensis, E. pauciflora and E. stellulata (mallee form). The Brumby Point area is interesting for the distinctive alternating bands of low woodland and shrubland. Leptospermum jingera, whilst occurring in the low woodland, is more commonly associated with the shrubland bands.

Conservation status

Leptospermum jingera is located in a remote and rugged area of the Buchan Headwaters Wilderness area of Alpine National Park. Despite the infrequently used fire track that bisects the only known population, the species does not appear to be threatened. The Victorian Department of Conservation and Environment (now Conservation and Natural Resources) have proposed to close and revegetate this track (1992: 166). Thus, following the criteria of Briggs and Leigh (1988: 7-13), the most appropriate conservation code is 2RC-. This conservation code indicates that L. jingera has a very restricted distribution of less than than 100 km, that it is rare although not considered endangered nor vulnerable, that it is represented within a national park or other proclaimed reserve and that the population size is unknown.

Discussion

Leptospermum jingera belongs in the L. brevipes sub-group as defined by Thompson (1989: 332) as its sepals are persistent on the fruit, it lacks woody fruit valves, it has seeds with a reticulate surface pattern and it has a restricted development of the terminal bud. The species appears to be most closely related to L. namadgiensis Lyne occurring on the Scabby and Yaouk Bill Ranges in the vicinity of the southern A.C.T. - N.S.W. border. These two species are remarkably similar in their morphology and ecology. Both share a splitting hypanthium in fruit and grow in sub-alpine habitats where they are most commonly found on the tops of ridges or mountain summits. The most obvious morphometric differences occur in type of bark, pedicel length, numbers of stamens and ovules and fruit length:breadth ratio. Bark and pedicel length are reliable discriminators between the two species. The bark of L. jingera is in loose papery layers at the base of the plant whilst that of L. namadgiensis is minni ritchi like (i.e. it splits longitudinally and the edges peel back to reveal new, green bark beneath) towards the base of the plant. Other characters exhibit ranges that closely approach or overlap each other, but when taken together and the geographic disjunction of c. 160 km is considered, the rank of species is suitable. Table 1 shows some comparisons between the two species.

Although L. brevipes is a widespread and variable species, it exhibits a consistent form throughout its range in Victoria, at least in the characters that separate it from L. jingera. In the field, the most obvious difference is the nature of the bark on larger stems, whilst characters of the flowers and fruit allow further differentiation. Table 1 shows some of the characters that distinguish L. jingera from L. brevipes.

Cuttings and seed of L. jingera were collected and have been incorporated into the Living Collections of the Australian National Botanic Gardens. Germination of seeds has proved to be be difficult. Seeds sown without any pretreatment (c. 70) did not germinate. The only success has been after stratification (3 seedlings from c. 70 treated and sown) or a 15 minute treatment with 6% H2O2 (3 seedlings from c. 300 treated and sown).

Further information relating to L. jingera, including specimen label data and a number of photographs, are available to view via the Centre for Plant Biodiversity Research and the Australian National Botanic Gardens World Wide Web biodiversity server. This server is located at http://155.187.10.12/. The Leptospermum studies can be found at http://155.187.10.12/leptospermum/leptospermum-lyne/leptospermum.html. Alternatively, select "Australian National Botanic Gardens" or "Centre for Plant Biodiversity Research" and under the item "Projects and activities on its WWW server" will be another selectable item, "Leptospermum taxonomy".

Acknowledgments

We are grateful to the curator of MEL for the loan of specimens. We thank Ian Telford (Australian National Herbarium, Centre for Plant Biodiversity Research) for comments on a draft of this paper, Kevin Thiele (Australian National Herbarium, Centre for Plant Biodiversity Research), for the illustration and Tim Mulcahy and Barrie Hadlow (Nursery, Australian National Botanic Gardens), for their efforts in germinating seeds of L. jingera.

References

Briggs, J.D. & Leigh, J.H. (1988). `Rare or Threatened Australian Plants.' Special Publication no. 14. (Australian National Parks and Wildlife Service: Canberra).

Conn, B.J. (1992). `Natural Regions of Victoria' (National Herbarium of Victoria).

Department of Conservation and Environment (1992). `Alpine National Park: Cobberas-Tingaringy unit: Management Plan.' (Department of Conservation and Environment: Victoria). 334 pp.

Ramson, W.S. (ed.) (1988). `The Australian National Dictionary.' (Oxford University Press: Melbourne). 814 pp.

Thompson, J. (1989). A revision of the genus Leptospermum (Myrtaceae). Telopea 3, 301-448.

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