Eucalyptus erosa A.R.Bean (Myrtaceae), a new stringybark species from central Queensland A.R. Bean Summary Bean, A.R. (2005). Eucalyptus erosa A.R.Bean (Myrtaceae), a new Stringybark species from central Queensland. Austrobaileya 7(1): 141-144. Eucalyptus erosa, a new species of the stringybark group (E. ser. Pachyphloius Blakely) is described, illustrated and diagnosed against closely related species. Key Words: Myrtaceae, stringybark, eucalypt taxonomy. Eucalyptus erosa, Queensland flora. A.R. Bean, Queensland Herbarium, Environmental Protection Agency, Brisbane Botanic Gardens Mt Coot-tha, Mt Coot-tha road, Toowong, Queensland, 4066, Australia. Introduction Eucalyptus series Pachyphloius Blakely Taxonomy comprises taxa commonly known as the ‘true stringybarks’ (Ladiges and Humphries 1986). Eucalyptus erosa A.R.Bean sp. nov. affinis E. They are characterised by the thick mackieanae sed plantulae foliis latioribus longitudinally fibrous bark persistent densius hirsutis, pedicellis longioribus, throughout the trunk and most or all branches, fructus disco piano et cotyledonibus and the seedlings with emergent oil glands latioribus differens. Typus: Queensland. bearing numerous radiating hairs, in appearance Maranoa District : 13 km N of Mt Moffatt like stellate hairs. Frequently they exhibit sessile Homestead, on road to Consuelo buds and fruits, and oblique adult leaf bases. Tableland, 27 April 1981, D.F. Blaxell 1883 Chippendale (1988) enumerated 21 species for & L.A.S. Johnson (holo: BRI; iso: CANB, MEL, NSW). the group while Brooker (2000) listed 28 species. The majority of these species occur in eastern Eucalyptus sp. (Carnarvon Range) in Ladiges New South Wales and eastern Victoria, but & Humphries (1986), Neish et al. (1995) several species extend to Queensland, mostly in higher altitude areas along the southern parts Eucalyptus sp. (Mt Moffatt HS D.F. BlaxelH of the Great Dividing Range in the south-east. 1883) in Bean et al. (2002) On the high ranges and plateaux between Well-formed tree to 30 metres high, Injune and Springsure, including the Consuelo lignotuberous, trunk straight. Bark persistent Tableland, two species of E. series except on small branches, coarsely fibrous to Pachyphloius are indigenous. One is stringy, grey on outside, brown underneath. E. laevopinea R.T.Baker, which also grows Juvenile leaves sub-opposite to alternate, widely on the New England Tableland much lanceolate to narrowly-ovate, 5-7 x 1.5-2 cm, further south. On the Consuelo Tableland, it strongly discolorous, apex acute, base cuneate forms a superb tall forest, “the best natural to obtuse, margins minutely denticulate, petioles stringybark forest in existence” (I. Brooker pers. 0.2-0.3 cm long; stems, petioles and leaves comm.). The second species (described here) is covered with clusters of simple radiating hairs, most closely related to E. mackieana. It grows in appearance like stellate hairs, each cluster on deep sandy soils derived from the 0.3-0.5 mm diameter. Intermediate leaves weathering of quartzose sandstone rock, and is broadly lanceolate, 7.5-9.5 x 2.5-3.5 cm, also a tree of impressive proportions. glabrous, slightly discolorous, apex apiculate, base oblique. Adult leaves falcate or lanceolate, 7-14 x 1.1-2.3 cm, alternate, concolorous, Accepted for publication 30 June 2005 penninerved, lateral veins at 30-45° to the 142 Austrobaileya 7 (1): 141-144 (2005) midrib; reticulation very sparse, with numerous Notes: The most remarkable feature of E. erosa large island oil glands, several per areole; is the consistent and conspicuous presence of intramarginal vein present, 0.5-1.3 mm from the marginal glands on the adult leaves. On the margin; apex acute, mucronate or uncinate, base newly emerging leaves (new growth), they are cuneate to oblique, margins erose due to readily observed as pustular glands crowded marginal glands (4-9 on each side of lamina); towards the distal end of the leaf (Fig. Id). On petioles 10-16 mm long. Inflorescences axillary, fully grown leaves, they are more or less evenly unbranched, 9-11 (-13) flowered umbellasters; distributed along the margins (Fig. lc). By this peduncles angular to flattened, 7-14 mm long; stage, the glands have usually erupted from the pedicels 2-4.5 mm long; immature buds surface along the margin, leaving a slightly sunken, elliptical structure, that is then more ellipsoidal; mature buds obovoid, 5.5-7 mm long, appropriately called a leaf-margin lenticel (Neish 3.5-4 mm in diameter, smooth and without ridges. Hypanthium obconical, 3.5-4 mm long; et al. 1995). In this species and a few others (e.g. E. denticidata), the leaf-margin lenticels operculum conical to apiculate, 2^1 mm long, are associated with irregularities in the leaf scar absent; stamens white, irregularly flexed, margin that are conspicuous to the naked eye. all fertile. Anthers reniform to cordate, versatile, In other species, the leaf margin irregularities anther slits confluent. Style terete, stigma blunt are much more subtle. or tapered. Ovary 3-4-1 ocular, ovules in 2 vertical rows. Fruits cupular to hemispherical, 4—6 mm “Irregular leaf margins” was one of the long, 6-7.5 mm in diameter, disc flat, 0.8-1.4 mm characters used by Ladiges & Humphries (1986) wide, valves 3-4, at rim level, pedicels 2.5-5 mm in their cladistic analysis of the stringybark long. Seeds pyramidal to D-shaped, 1.6-2.0 mm group. They noted its presence in E. erosa (as long, not toothed, dark brown, surface faintly E. sp. Carnarvon Range), but not for any other reticulate, hilum terminal. Chaff similar in size member of the Stringybark group. Neish et al. and shape, but paler. Fig. 1. (1995) documented the occurrence of this character in five species of Eucalyptus, Additional specimens examined: Queensland. including one additional species of stringybark, Maranoa District: 146 km NW of Injune on road to E. laevopinea. However, this character is much Consuelo Tableland, Sep 1977, Blaxell 1529 & Armstrong (BRI, NSW); 155 km NW of Injune on more widespread in the genus than has yet been road to Consuelo Tableland, Sep 1977, Blaxell 1524 & reported (Bean, unpubl. obs.). Armstrong (BRI, NSW); between Warrong and Mt Moffatt, NW of Injune, Apr 1975, Brooker B4867, E. erosa differs from the closely related B4868 (BRI, CANB); Great Dividing Range, c. 80 km E. mackieana by its juvenile leaves 1.5-2 cm SW of Rolleston, Kenniff Caves, Jun 1977, Crisp 3068 wide (0.5-1 cm wide for E. mackieana), the (BRI, CANB, NSW); 6 km W of Mt Moffatt HS, May seedling leaves with more than 30 hair clusters 1982, Neldner & Thomas 749 (BRI). Warrego District: c. 0.5 km N of Pumphole Spring, Dooloogarah Creek, per square centimetre (vs. <12 for Feb 1977, Martensz 1148, 1149 & Johnston (BRI, E. mackieana), the pedicels 2.5-5 mm long in CANB). faiit (1-2.5 mm long inE. mackieana), and fruits with a flat disc (convex disc in E. mackieana). Distribution and habitat: Eucalyptus erosa is According to Ladiges & Humphreys (1986), confined to the Mt Moffatt section of Carnarvon E. erosa has cotyledons 10-13 mm wide, National Park, north-west of Injune, and the compared to 5-7 mm wide for E. mackieana. adjacent grazing property “Dooloogarah”. It grows on coarse sandy colluvials derived from E. mackieana has long been spelt outcropping quartzose sandstone, at altitudes E. mckieana, but Recommendation 60C.4 of the of700-900 metres. It occurs in association with IUCN (Greuter et al. 2000), stated that “The Angophora leiocarpa (G J.Leach) K.R.Thiele & Scottish patronymic prefix Mac, Me or M’, Ladiges, Eucalyptus grisea L.A.S.Johnson & meaning “son of’, should be spelled ‘mac’ and K.D.Hill and Callitris glaucophylla Joy united with the rest of the name”. Thomps. & L.A.S.Johnson. Conservation status: There are no appreciable Phenology: Flowers have been recorded for threats to this species. Under the IUCN criteria May. Fruits may be found throughout the year. (IUCN 2001), E. erosa classifies as ‘Least Bean, Eucalyptus erosa 143 Fig. 1. Eucalyptus erosa. A. juvenile leaves *0.5. B. branchlet bearing axillary bud clusters x0.5. C. adult leaf showing the marginal glands *1. D. newly emerging adult leaves with pustular marginal glands x4. E. umbellaster of mature buds (some buds have been shed) x3. F. umbellaster of mature fruits (some fruits have been shed) x3. G. mature fruit, viewed from above x3. A,C from Maxell 1883 & Johnson; B,D from Crisp 3068; E from Neldner & Thomas 749; F,G from Martensz 1149 & Johnston (all BRI). Del. W. Smith. 144 Austrobaileya 7 (1): 141-144 (2005) Concern’. Hence no conservation status is 55. Australian Government Publishing Service: recommended. Canberra. Etymology: The specific epithet is derived from Greuter, W., McNeill, J., Barrie, F.R., Burdet, H.M., Demoulin, V., Filgueiras, T.S., Nicholson, D.H., the Latin erosus, referring to the erose Silva, PC., Skog, J.E., Trehane, P, Turland, N.J. (corroded, irregularly toothed, or apparently & Hawksworth, P.L. (2000). International gnawed) margins of the adult leaves in this Code of Botanical Nomenclature (Saint Louis species. Code). Regnum Vegetabile, Volume 138. International Association for Plant Taxonomy (Europe). Acknowledgements Iucn (2001). IUCN Red List Categories and Criteria: I am grateful to Will Smith for the illustrations Version 3.1. IUCN Species survival and Peter Bostock for the Latin diagnosis. Commission. IUCN: Gland, Switzerland/ Cambridge, UK. References Ladiges, PY. & Humphries, C.J. (1986). Relationships Bean, A.R., Guymer, G.P. & Jessup, L.W. (2002). in the stringybarks. Eucalyptus L’Herit. Myrtaceae. In R.J.F. Henderson (ed.), Names informal subgenus Monocalyptus series and Distribution of Queensland Plants, Algae Capitellatae and Olsenianae. phylogenetic and Lichens, pp. 119-32. Environmental hypotheses, biogeography and classification. Protection Agency: Brisbane. Australian Journal of Botany 34: 603-632. Brooker, M.I.H. (2000). A new classification of the Neish, P.G., Drinnan, A.N. & Ladiges, PY. (1995). genus Eucalyptus L’Her. (Myrtaceae). Anatomy of leaf-margin lenticels in Eucalyptus Australian Systematic Botany 13: 79-148. denticulata and three other eucalypts. Australian Journal of Botany 43: 211-221. Chippendale, G.M. (1988). Eucalyptus, Angophora (Myrtaceae), Flora of Australia Vol. 19: 142—