Erythrophleum chlorostachys (F.Muell.) Baill.

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 : 414-416

Erythrophleum chlorostachys (F.Muell.) Baill. ,

Hist. Pl. 2: 150 (1870)

Laboucheria chlorostachya F.Muell., J. Proc. Linn. Soc., Bot. 3: 159 (1859). Erythrophleum laboucheri F.Muell., Ann. Rep. Gov. Bot. & Dir. Bot. Gard. 1862 –1863: 12 (1863), nom. illeg., nom. superfl., as ‘ E. laboucherii ’. Erythrophleum laboucheri F.Muell. ex Benth., Fl. Austral. 2: 297 (1864), nom. nov., isonym, as ‘ E. laboucherii ’. Erythrophleum chlorostachys (F.Muell.) Hennings ex Taub. , Nat . Pflanzenfam. [Engler & Prantl] 3(3): 127 (1892), isonym.

Type citation: ‘ A plagis boreali-occidentalibus Australiae usque ad flumen Burdekin tractus orientalis, tam in solo fertiliore quam steriliore planitierum montiumque satis frequenter obvia.’

Type: Victoria River, [Northern Territory], September 1855, F. Mueller s.n. (lecto, here designated: MEL 1524198 ; isolecto: MEL 1524197 ) .

Residual syntypes (all representing E. chlorostachys ): Northern Territory: Arnhem Land , F. Mueller s.n. ( K 000756965 , K 000756966 (photos at MEL)); Victoria River , June 1856, F. Mueller s.n. ( K 000756961 , K 000756963 , K 000756967 ); Gulf of Carpentaria , F. Mueller s.n. ( MEL 1524187 ); seen at the Burdekin River, Queensland, and Port Essington , Northern Territory, 1849, F. W. L. Leichhardt s.n. ( NSW 415300 , P 02939477 ) .

Possible syntypes: Australia: location, collector and date unknown ( K 000756964 ); northern coast of Arnhem Land , J. M’Kinlay s.n. ( MEL 1524178 ); scrub towards the Gulf of Carpentaria, lat. 17°S, J. M. Stuart ( MEL 1524189 ) .

Excluded syntype (representing E. pubescens ): Strangways River , n.d., F. Mueller ( AD 97813219 , MEL 1524186 ) .

Tree up to (4–) 6–9 m tall, many-branched with a spreading crown, resprouting after fire; bark dark grey to blackish, roughly tessellated and irregularly, shallowly furrowed; branchlets smooth, rarely with any cork, usually glabrous, not glaucous. Leaves with petiole 23–72 mm long; rachis 24–115 mm long; pinnae usually (1)2(3) pairs, sometimes 1 or 2 pinna aborted so appearing alternate; secondary rachises 50–170 mm long; leaflets alternate, mostly 3–6(–7) per pinna, orbicular to somewhat deltoid, mostly 31–87 mm long, 31–80 mm wide, slightly larger on resprout growth (up to 90 mm wide), obtuse to cordate, slightly asymmetric, rounded, obtuse or emarginate apically, glabrous or rarely very finely pubescent when very young, soon glabrescent; petiolules 2.5–7 mm long; venation conspicuous. Racemes usually simple, rarely once-branched, mostly 60–105 mm long; axis 0.9–1.6 mm thick below the flowers, glabrous. Flowers 55–100; distinctly pedicellate, pedicels 0.5–1.2 mm long at anthesis (occasionally sessile in bud); cream to greenish-yellow. Floral bracts 0.7–0.9 mm long, margins ciliate, lamina glabrous. Calyx 2.3–3.8 mm long; lobes shorter than the tube, 0.9–1.2 mm long, ciliate only on margins. Petals 2.8–3.8 mm long, exserted by 0.8–2.3 mm, with ciliate margins and glabrous adaxial surface. Stamens alternately long and short, filaments 3.2–6.4 mm long, glabrous. Anthers 0.7–1.0 mm long. Ovary densely pubescent, 1.8–2.7 mm long. Style 1.9–2.8 mm long. Pod often slightly curved, dehiscing along both sutures, (2–)3–8-seeded, (90–) 120–210 mm long, 23–32 mm wide, apex acute to apiculate; dark reddish-brown, glabrous; stipe of pod often asymmetric, 12–20 mm long. Seeds brown, suborbicular, 10–11 mm long, 9–10 mm wide, 2.5–5.1 mm thick; aril 2–4.8(–7) mm long. ( Fig. 3 )

Illustrations

K. Brennan, Wildfl. Kakadu 52, pl. 83 (1986); M. Clark & S. Traynor, Pl. Trop. Woodl. 50, fig. (1987); J. Brock, Top End Native Pl. 150, pl. (1988); J. H. Ross in A. E. Orchard (Ed.), Fl. Australia 12: 70, fig. 28 (1998); P. Moore, Guide Pl. Inland Australia 392–3, pl. (2005).

Distribution

Endemic in northern Australia, from Wyndham and along the Ord River , through central Northern Territory to the Gulf of Carpentaria , Queensland .

Habitat

Usually found in open woodland or savanna on sand or clayloam soils.

Phenology

Flowering recorded for August–December and fruiting recorded for February–September.

Etymology

The epithet is derived from the Greek chloro - (green) and - stachys (spike), in reference to the greenish flower spikes.

Notes

The following combination of characters is diagnostic: tree (4–) 6–9 m tall, many-branched with a spreading crown, branchlets glabrous, not glaucous; leaves with pinnae usually in (1)2(3) pairs; leaflets mostly 3–6(–7) per pinna, orbicular to somewhat deltoid, slightly asymmetric; glabrous or rarely very finely pubescent when very young, soon glabrescent; petiolules 2.5–7 mm long; raceme axis glabrous; pedicels 0.5–1.2 mm long; calyx 2.3–3.8 mm long; lobes 0.9–1.2 mm long, ciliate only on margins; stipe of pod 12–20 mm long.

Close examination of specimens at MEL and images of the remaining syntypes of Laboucheria chlorostachys showed that most of the specimens are referable to the taxon defined here as E. chlorostachys . Of the six possible syntypes identified above, three possible syntypes were likely to be available to Mueller at the time of description, but cannot be verified as original material. One syntype is referable to a different taxon than the majority, namely E. pubescens . Of

the remaining two specimens, the more complete specimen was selected as lectotype.

The lectotype bears a label with the name ‘ Laboucheria chlorostachys Ferd. Mueller. ’ This collection is in fruit, so the distinguishing floral characteristics cannot be determined on this specimen, but the leaf characters and location clearly distinguish it from E. arenarium and E. pubescens .

Ferdinand Mueller (1859) described Laboucheria chlorostachya on the basis of material that mostly belonged to the entity here typified; however, material later illustrated for the Iconography of Australian Species of Acacia and Cognate Genera ( Mueller 1888) actually represents E. pubescens . The excellent lithograph from that work is reproduced here to illustrate the new species. In the treatment by Ross (1998), fig. 28 represents E. chlorostachys , whereas fig. 31 and 43 represent E. pubescens .

Known as Top End ironwood.

Representative specimens

WESTERN AUSTRALIA. Cambridge Gulf , 1886, H. S . Banford & E . W . Nyulasy s.n. ( MEL); Buttons Gap, Ord River , 17 Apr. 1956, N. T . Burbidge 5196 ( CANB, MEL); E bank of the King River , Kununurra, 12 Dec. 2009, G. Byrne 3693 ( MEL, PERTH); Wyndham , 24 May 1944, C. A . Gardner 7257 ( PERTH, 2 sheets); W of Cambridge Gulf , 1887, A. J . Keiller s.n. ( MEL); Five Rivers Lookout, Wyndham , 20 Aug. 2001, R. C . H. Shepherd 76 ( MEL); ~ 1 km uphill from Camp Nicholas, Smoke Creek , SW of Lake Argyle, 5 May 1980, A. S . Weston 12284 ( PERTH) . NORTHERN TERRITORY. Stuart Hwy, 6 miles [~ 9.6 km] NW of Katherine , L. G . Adams 811 ( BRI, CANB); 4-mile farm, CSIRO Research Station, Katherine , 7 Dec. 1966, L. G . Adams 1653 ( BRI, CANB, E, MEL, NSW); 3 km N of Dunmurra, Stuart Highway , 2 July 1974, A. C . Beauglehole 46481 & G . W . Carr 2702 ( BRI n.v., MEL); U .D. P. Falls, ± 80 km NE of Pine Creek , 12 Aug. 1978, A. C . Beauglehole 58566 & E . G . Errery ( MEL); Weimoor Springs , 9 Aug. 1962, M. Cole 132 & D.Provan ( BRI); Fitzmaurice River basin, 13 May 1994, C. R . Dunlop 9979 & P . K . Latz (DNA n.v., MEL); Maningrida , 1961, L. Gressitt 2668 ( BRI); Fish River , 11 Feb. 1991, D.Larcombe 2 (DNA); Kakadu National Park, 22 km SSW of Cooinda on Pine Creek Road, 19 May 1980, M. Lazarides 8845 ( CANB, DNA); Pine Creek , 6 June 1973, M. Parker 113 ( BRI, DNA, NT); Tortilla Flats , 4 Nov. 1974, M. Parker 528 ( CANB, DNA, n.v., NE, n.v.); No. 7 Stock Route Bore ( S of Dunmarra), undated, A. L . Rose s.n. ( BRI); 40 miles [~ 64.4 km] S of Katherine , 7 Sep. 1961, N. H . Speck 1643 ( AD, BRI, CANB, MEL, NSW, PERTH, 2 sheets); 17 mi. W of Katherine on road to Willaroo , 17 July 1967, D. E. Symon 5188 ( AD, CANB, K, NT); Katherine National Park , 8 July 1979, M. D. Tindale 6040 & C . R . Dunlop ( CANB, DNA n.v., NSW); Ranger HQ, Nitmiluk National Park , 13 Dec. 1990, G. Wightman 5205 (DNA); Mary River Camp, June 1955, M. White M . R . 18 ( CANB). QUEENSLAND. Etheridge River , Armit 679 ( MEL, 2 sheets); 14 miles [~ 22.6 km] SE of Carpentaria Downs Station, 12 July 1954, N. H . Speck 4702 ( AD, CANB, NSW, PERTH) .

Figures

Fig. 3. Erythrophleum chlorostachys: (a, b) habit and habitat; (c) bark; (d) inflorescence with very young buds; (e) flower buds; (f) flowering inflorescence (g) portion of flowering inflorescence showing shortly pedicellate flowers, glabrous axis and glabrous calyx; (h) glabrous new adult growth; (i) pod; (j) seed. Vouchers: King River, Kununurra, WA, G.Byrne 3693, PERTH (a, c–g); Ragged Range, WA, not vouchered (b); Katherine, NT, L.G.Adams 1653, NSW (h); ‘Katherine National Park’, NT, M.D.Tindale 6040 & C.R.Dunlop, NSW (i, j). Images by G. Byrne (a, c–g), and R. L. Barrett (b, h–j).