Erythrophleum pubescens R.L.Barrett & M.D.Barrett, 2023

Barrett, Russell L. & Barrett, Matthew D., 2023, Taxonomic revision of Australian Erythrophleum (Fabaceae: Caesalpinioideae) including description of two new species, Australian Systematic Botany 36 (5), pp. 401-426 : 416-418

Erythrophleum pubescens R.L.Barrett & M.D.Barrett , sp. nov.

Type: Carson Escarpment, N of Coucal Gorge, Drysdale River National Park , Western Australia, 17 August 1975, A. S. George 13961 (holo: PERTH 2211939 ; iso: CANB 267799 , K, n.v.) .

Tree 8–20(–30) m tall, many-branched with a spreading canopy, resprouting after fire, rarely flowering as a shrub when frequently burnt; bark dark grey to blackish, tessellated; branchlets usually prominently fissured, corky, pubescent when young, newest growth with rusty hairs, eventually becoming glabrous. Leaves with petiole 18–51 mm long; rachis 35–138 mm long; pinnae usually 2 or 3 pairs; secondary rachises 35–155 mm long; leaflets alternate, mostly 5–11 per pinna, obliquely elliptic, ovate or obovate, mostly 19–62 mm long, 9–45 mm wide, resprout growth often markedly larger; attenuate, distinctly asymmetric, rounded, obtuse or emarginate apically, discolourous, with scattered hairs basally and on the petiolules, eventually becoming glabrous; petiolules 1.5–4 mm long; venation conspicuous. Racemes simple to 5-branched, (45–) 70–160 mm long; axis 1.0– 1.7 mm thick below the flowers, moderately to densely pubescent, hairs white or rusty. Flowers 62–125; sessile; cream to greenish-yellow. Floral bracts 0.5–0.7 mm long, margins ciliate and lamina pubescent. Calyx 1.9–2.5 mm long; lobes shorter than the tube, 0.5–0.9 mm long, pubescent on surface and margins. Petals 2.3–2.9 mm long, pubescent at the margins, otherwise glabrous. Stamens alternately long and short, filaments 3.4–8.9 mm long, glabrous. Anthers 0.6–0.7 mm long. Ovary densely pubescent, 2.1–3.4 mm long. Style 0.7–1.7 mm long. Pod often slightly curved, dehiscing, at least initially, along one suture only, (1–)2–7- seeded, 97–120 mm long, 26–46 mm wide, apex acute to apiculate; dark reddish-brown, pubescent when young, glabrescent; stipe of pod often lateral, 8–10 mm long. Seeds dark brown, suborbicular, 12–15 mm long, 9–12 mm wide, 4.5–6.0 mm thick; aril 5–8 mm long. ( Fig. 4 , 5 .)

Illustrations

F. Mueller, Iconogr. Austral. Acacia 13: t. 9 (1888). C. A. Gardner & H. W. Bennetts, Poison. Pl. West. Australia, pl. 3 (1956); D. Levitt, Pl. People pl. 8 (1981); J. R. Wheeler in J. R. Wheeler (Ed.), Fl. Kimberley Region 347, fig. 104a (1992); C. R. Dunlop et al., Fl. Darwin Region 2: 32, fig. 13 (1995); K. F. Kenneally et al., Broome & Beyond. Pl. & People Dampier Peninsula 76, [upper pl. only] (1996); J. H. Ross in A. E. Orchard (Ed.), Fl. Australia 12: 70, fig. 31, 43 (1998); J. Milson, Trees Shrubs NW Queensl. 18–19, pl. (2000); W. Cooper, Fruits Austral. Trop. Rainfor. 102, fig. (2004); J. Beasley, Pl. Trop. N. Queensl. 156, pls (2006); J. Beasley, Pl. Cape York 43, pls (2012), (all as E. chlorostachys ).

Distribution

Endemic in northern Australia, from near Derby in the western Kimberley, WA, through NT and islands of the Gulf of Carpentaria to north-eastern Qld, Cape York and some Torres Strait islands.

Habitat

Usually found in open Eucalyptus or mixed forest, woodland or savanna on sandstone- or basalt-derived soils.

Phenology

Flowering mostly July–November, but also recorded for March and May. Fruiting mostly recorded for April–August.

Etymology

The epithet is from the Latin pubescens (with short, soft hairs), in reference to the presence of hairs on most parts at least when young, diagnostically always present on the raceme axis and outer surfaces of the calyx.

Notes

The following combination of characters is diagnostic: tree 8–20 m tall, many-branched with a spreading canopy, branchlets pubescent when young; leaves with pinnae usually in 2 or 3 pairs; leaflets mostly 5–11 per pinna, attenuate, distinctly asymmetric, with scattered hairs basally and on the petiolules; petiolules 1.5–4 mm long; raceme axis moderately to densely pubescent; calyx 1.9–2.5 mm long; lobes 0.5–0.9 mm long, pubescent on surface and margins; flowers sessile; stipe of pod 8–10 mm long.

Although the majority of the syntypes represent the taxon here recognised as E. chlorostachys sensu stricto, the mostused concept in the literature, and apparently the main source for Mueller’s original description and his illustration in Iconogr. Austral. Acacia 13: t. 9 (1888) is the taxon described here as E. pubescens .

Resprout foliage of E. pubescens is large, similar in size to that of E. arenarium , but it can be separated by the presence of scattered to dense hairs on the branchlets, petioles and petiolules. Juvenile pinnae also remain distinctly asymmetric in most cases, although not always as distinctly as the adult pinnae.

Widely known as Cooktown ironwood under the name E. chlorostachys , a species that is not known to occur near Cooktown; so, this common name must logically be transferred to E. pubescens , or its use discontinued. There are many First Nations names, which may also include E. chlorostachys , as detailed in Table 1.

The most useful characters for distinguishing the three species are presented in Table 3.

Representative specimens

WESTERN AUSTRALIA. Drysdale River , S of river mouth on Carson River Station , 24 June 2018, M. D.Barrett MDB5902 ( PERTH); ‘ Prince Regent’ [Roe] River, 1891, Bradshaw & Allen s.n. ( MEL, NSW); Five Rivers Lookout , 7 Feb. 2010, G. Byrne 3721 ( PERTH); Gorge in Saw Ranges , NW of Dunham River, 6 Nov. 1992, K. Coate 224 ( PERTH); Careening Bay , 1820, A. Cunningham 227 ( BM, n.v., K, NSW); Charnley River [Station], 1 km N of Potts Camp, 26 June 2012, H. Dauncey H 666 ( PERTH); Cone Mountain, on peninsula between Vansittart Bay and Napier Broome Bay , ± 25 km WNW of Kalumburu, 22 may 1984, S. J. Forbes 2085a ( MEL); Kuri Bay , Bonaparte Archipelago, 2 Sep. 1985, P. R. Foulkes 340 ( PERTH); Lawley River , 30 July 1921, C. A. Gardner 997 ( PERTH); Bushfire Hill, Prince Regent [Nature] Reserve, 15 Aug. 1974, A. S. George 12300 ( PERTH); Kununurra , 15 Sep. 1982, C. Glover 112 ( MEL, PERTH); Boiga Falls, Drysdale River National Park , 4 Aug. 1975, K. F. Kenneally 3046 ( CANB, PERTH); Loc. 4.0, SE of Beverley Springs Homestead, 19–26 May 1979, B. G. Muir et al. 734 ( PERTH); Jameson Arch, Bachsten Camp track, Mount Elizabeth Station , 15 Sep. 2003, G. & N. Sankowsky 2249 ( PERTH); Adcock Gorge , 13 Apr. 1980, D. E. Symon 12095 ( AD, K, PERTH) . NORTHERN TERRITORY. Darwin, Nov. 1929, F. A. K. Bleeser 503 ( MEL); Sturt Plateau, Dungowan Station , 12 Oct. 2000, K. Brennan 4583 (DNA); Black Point, 29 Sep. 1968, N. Byrnes 1043 ( AD, NT, PERTH); 77.3 miles [~ 124.4 km] S of Katherine , 9 Sep. 1957, G. Chippendale NT 3732 ( AD, NSW, NT, PERTH); Arnhem land 8.6 km S of Walker River airstrip, 11 Oct. 1987, M. Clark 1607 (DNA); Kapalga Ref. 1211, 15 Dec. 1976, R. Collins BC172 ( CANB, DNA, n.v., MEL, NSW); Litchfield NP, Walker Creek area , 15 Mar. 1995, I. Cowie 5303 (DNA); Narbalek, 25 Oct. 1987, C. R. Dunlop 7145 (DNA, n.v., MEL, NSW); Cutta Cutta , 13 July 1990, M. Evans 3270 ( CANB, DNA, MEL, NSW); Cutta Cutta Reserve , 23 Nov. 1993, J. Egan 2873 (DNA); Newcastle Waters, 17 July 1911, G. F. Hill 473 ( MEL); Port Darwin, 1883, Holtze ( MEL); Black Jungle area , 17 Sep. 1986, N. M. Smith 101 (DNA); Lameroo Beach, Darwin, 8 Oct. 1986, N. Smith 128 (DNA); on Stuart Highway 42 km N of Carpentaria Highway junction, 5 Sep. 1981, T. Whaite 3979 & J . Whaite ( CANB, DNA, n.v., K, n.v., MO, n.v., NSW) . QUEENSLAND. Georgetown, n.d., Armit 717 ( MEL); Cooktown , 13 May 1970, S. T. Blake 23184 ( BRI, CNS, n.v., MEL, NSW, PERTH); Laura sandstone area N of Laura River near Early Man site, 16 May 1975, N. B. Byrnes 3365 ( BRI, MEL, QRS, n.v.); Croydon , 24 Aug. 1913, R. H. Cambage 3920 ( NSW, 2 sheets); Dutton River Station , ~ 46 km NW of homestead and 110 km E of Richmond, 15 June 2012, E. Leitch QDA003815 ( BRI); Emu Creek Station , NE of Petford, 12 Nov. 2005, K. R. McDonald KRM4610, L. J. Roberts & J. A . Covacevich ( BRI, MEL); creek flowing into Emu Lagoon, Errk Oykangand National Park , 1 Sep. 2010, K. R. McDonald KRM9767 ( BRI); 42.9 km by road W of Georgetown, near Blancourt Station turnoff, 19 Sep. 2010, K. R. McDonald KRM9840 ( BRI, MEL); Kings Plain Station, near Lily Dam , 5 Nov. 2015, K. R. McDonald KRM17554 ( BRI, MEL); Weipa North township, State School oval, Jan. 1981, A. Morton 1183 ( AD, MEL, 2 sheets); Endeavour River , 1882, W. A. Persieh 719 ( MEL); Granite Creek , 12 km SW of Mareeba, 16 Nov. 1995, B. S. Wannan 213 & L . Lynch ( NSW); Mareeba , road from Kennedy Highway to Springmount, 27 June 2001, J. J. Wieringa 4178, L. J. G. van der Maesen, A. Bruneau & P . Herendeen ( NSW, WAG, n.v.); Gamboola, Mitchell River , 22 Sep. 1882, Wools s.n. ( MEL) .

Figures

Fig. 4. (Caption on next page)

Fig. 5. Erythrophleum pubescens: (a) habit and habitat; (b) bark; (c) natural blaze on trunk showing red heartwood prized for woodworking; (d) juvenile, asymmetric pinnae; (e) pubescence on new adult growth; (f) asymmetric pinna with sparse hairs; (g) portion of inflorescence showing sessile flowers, pubescent axis and pubescent calyx; (h) seed. Vouchers: King Edward River, WA, not vouchered (a, b, d); Mount Fyfe, Drysdale River Station, WA; not vouchered (c); Prince Regent Nature Reserve, WA, A.S.George 12300, PERTH (e, h); Drysdale River National Park, WA, A.S.George 13961, PERTH (f, g). Images by R. L. Barrett.