Daviesia pachyphylla Mueller (1863: 15)

Crisp, Michael D., Cayzer, Lindy, Chandler, Gregory T. & Cook, Lyn G., 2017, A monograph of Daviesia (Mirbelieae, Faboideae, Fabaceae), Phytotaxa 300 (1), pp. 448-450 : 448-450

129. Daviesia pachyphylla Mueller (1863: 15) , Bentham (1864: 82), Crisp (1995: 1220). Type: ‘In montibus juxta flumina Gardner et Phillips River. Maxw.’ Holotype: MEL; isotype: K

Slender (or occasionally compact) shrubs to 1.5 m high, glabrous, glaucous to pruinose. Root anatomy with anomalous secondary thickening (cord type). Branchlets spreading to ascending, often arching, terete, smooth except for phyllode scars, commonly pruinose. Phyllodes crowded with bases overlapping along branchlet, diverging at 45–90°, thick, terete, usually narrowly conical, i.e. tapering from a broad base to acuminate apex, occasionally also slightly constricted at base, often slightly recurved at apex, pungent, articulate at base, 12–27 mm long, 4–10 mm diam. at base, appearing succulent but filled with pith, smooth, glaucescent to pruinose. Seedling phyllodes becoming larger over the first 4 or 5 nodes, the first 3 nodes 8–9 × 1–1.5 mm, then transitory over the next 3 or 4 nodes to mature size; cotyledons present even when plant is 1200 mm high, elliptic, ca. 11 × 4 mm. Unit inflorescences 1 per axil, racemose, 2–7-flowered; peduncle often quite thick (up to 1 mm), 0.5–5 mm long; rachis 1.25–6 mm long; subtending bracts ± appressed, acuminate to oblong, entire or lacerated at the apex, 0.5–2 mm long. Pedicels 2–4.5 mm long. Calyx 3.5–4 mm long including the ca. 1 mm receptacle; upper 2 lobes united in a truncate, scarcely emarginate lip, ca. 0.5 mm long, lead grey tending to pruinose; lower 3 lobes acuminate, minute (<0.25 mm long). Corolla : standard transversely elliptic, emarginate, cordate, 5.5–6 × 6.5–8 mm including the 1.5–2 mm claw, yellow to orange with a dark red-brown centre; wings oblong to obovate, apex rounded and incurved to enclose the keel, auriculate, with another lobe opposite on the abaxial margin, 4.5–7 × 2–3 mm including the 1.5–2 mm claw, red to dark red-brown; keel half very broadly obovate, acute, auriculate, saccate, 4–5 × 2 mm including the ca. 1.5 mm claw, red to dark red-brown. Stamens strongly dimorphic: inner whorl of 5 with slightly longer, terete filaments and round, versatile anthers with confluent thecae; outer whorl of 5 with slightly shorter, compressed filaments and oblong, basifixed, 2-celled anthers; filaments free. Pod obliquely shallowly obtriangular, acuminate, compressed, 13–14 × 8.5–9 mm; upper suture slightly sigmoid; lower suture acute. Seed not seen. ( Fig. 130 ).

A MONOGRAPH OF DAVIESIA

Phytotaxa 300 (1) © 2017 Magnolia Press • 281

Common name:— Ouch Bush.

Flowering period:— July to October. Fruiting period: Immature fruits from August, mature from November to January.

282 • Phytotaxa 300 (1) © 2017 Magnolia Press

CRISP ET AL.

Distribution:— Western Australia, mainly near the coast from Fitzgerald River National Park (including the Barrens) north to Ongerup and east to Ravensthorpe and Munglinup.

Habitat:— Grows on sandy or gravelly laterite in heath dominated by Allocasuarina , Eucalyptus , Hakea and Banksia .

Selected specimens (37 examined):— WESTERN AUSTRALIA. Eyre: 11 km from Ravensthorpe, near Esperance turnoff on Ravensthorpe – Hopetoun road, 33°37’S, 120°09’E, F . Lullfitz 5293, 3 August 1966 ( CANB, PERTH); 25 km NNW of Ravensthorpe, North Road , 1 km N of junction with Hayes Road, 33°22’S, 119°59’E, M . D. Crisp 4992, 10 January 1979 ( CBG, PERTH); near Dempster Inlet, Fitzgerald River Reserve , 20 km from coast, 33°37’S, 120°09’E, E. C . Nelson ANU 16729 , 5 October 1972 ( CANB, PERTH); Mt Desmond , 11 km SE of Ravensthorpe, 33°37’S, 120°09’E, M . D. Crisp 4949, 8 January 1979 ( CBG); Boat Harbour , 34°31’S, 118°49’E, N. G . Marchant 70/243, 14 August 1970 ( PERTH). Roe: Jerramungup , 33°57’S, 118°54’E, C. E . Woolcock D 43, 31 July 1981 ( CBG). CULTIVATED. Australian National Botanic Gardens, ex. W. A ., 11 km SE of Ravensthorpe, Mt Desmond , M . D. Crisp 4949, 8 January 1980, seedling ( CBG) .

Affinity:— This species has thick phyllodes that are packed with pith, and as such is similar only to D. crassa , which differs in having erect, clavate phyllodes (i.e. proportionally narrower and always tapering to the base) and smaller flowers (e.g. standard is ca. 6 mm broad) that are pure yellow with no darker markings.

Figures

FIGURE 130. Daviesia pachyphylla. A. Flowering branchlet. B. Inflorescence. C. Pod. A, B from Crisp 5531 (type); C from Crisp 6147. Drawn by B-J. Osborne.