Daviesia audax Crisp (1995: 1175)

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

30. Daviesia audax Crisp (1995: 1175) . Type: Western Australia, Roe, 0.5 km E of Harrismith , 32°56’S, 117°52’E, M. D. Crisp 6155, J. Taylor & R. Jackson, 26 September 1979. Holotype: CBG; isotypes: K, MEL, MO, NSW, PERTH

Erect, usually single-stemmed shrubs or small trees, to 2 m high, glabrous, glaucescent to glaucous. Root anatomy unknown. Branchlets ascending, angular. Phyllodes scattered, erect, narrowly elliptic to narrowly obovate, thick, rigid, apically acuminate and pungent, gently narrowed to the base, with a thickened articulation at branchlet, (20) 25–65 × 5–10(–14) mm, venation obscure except midrib. Unit inflorescences 1–3 per axil, reduced to 1 flower each (with a cluster of bracts at the base of each pedicel); peduncle nil; bracts appressed, oblong, ca. 1 mm long. Pedicels 2–4 mm long. Calyx 4–4.5 mm long including the 1–1.5 mm receptacle, lightly ribbed; upper 2 lobes united in a truncate lip with recurved lobes, ca. 1–1.2 mm long; lower 3 lobes triangular, ca. 0.8 mm long. Corolla : orange with red markings; standard transversely broadly elliptic to transversely elliptic, emarginate, 5–7 × 5.5–8 mm including the ca. 1.5 mm claw, with 2 calli at the base of the lamina; wings broadly elliptic, apically rounded, incurved and overlapping to enclose the keel, deeply auriculate, 5–6 × 2–3 mm including the ca. 2 mm claw; keel half transversely elliptic, beaked, auriculate, saccate, 5–7 × 2.5 mm including the ca. 2 mm claw. Stamens strongly dimorphic: inner whorl of 5 with longer, slender, terete filaments and shorter, round, versatile anthers with confluent thecae; outer whorl of 5 with shorter, broader, compressed filaments and longer, narrower, 2-celled, basifixed anthers; filaments free. Pod obliquely obtriangular, acuminate, compressed but thick-walled, 18–25 × 10–12 mm; upper suture almost straight to slightly sigmoid; lower suture scarcely acute to scarcely obtuse. Seed obloid, 7.5–8 mm long, ca. 4.5 mm broad, ca. 3 mm thick, light or orange brown with black mottling; aril 2.5–3 mm long. ( Fig. 31 ).

Flowering period:— August to October. Fruiting period: November.

Distribution:— Western Australia, southern wheatbelt, extending in a narrow band from Harrismith to east of Lake King.

Habitat:— Well-drained, light grey sand to light sand over laterite to gravelly laterite, in heathland dominated by tall Grevillea .

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CRISP ET AL.

A MONOGRAPH OF DAVIESIA

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Selected specimens (17 examined):— WESTERN AUSTRALIA. Avon: Harrismith , 0.5 km E of town, 32°56’S, 117°54’E, M . D. Crisp 5527, 28 January 1979 ( CBG). Roe: 10 km NE of Kukerin along road to Tarin Rock , 33°09’S, 118°08’E, M . D. Crisp 5535, 28 January 1979 ( CBG); 14.5 km from Lake King towards Newdegate , 33°06’S, 119°32’E, J . W . Wrigley 5529, 6 November 1968 ( CBG, PERTH); 11 km W of Lake King towards Perth , 33°06’S, 118°34’E, F . Lullfitz 5550, 8 October 1966 ( PERTH); 27 km E of Lake Grace , 33°06’S, 118°12’E, A . S . George 5681, 30 August 1963 ( PERTH) .

Affinity:— This species presents a strong superficial resemblance to D. daphnoides , which has similarly shaped, rigid, erect, pungent phyllodes. However, the latter differs in having conspicuous lateral venation, 2–4- flowered racemes with a distinct rachis and pods turgid at the base. Daviesia audax is probably related to D. nudiflora , which has single-flowered unit inflorescences and a similar floral morphology; also, in some forms of D. nudiflora , the pungent phyllodes are similar in shape and orientation to those of D. audax . Characters distinguishing D. nudiflora include the lack of an articulation at the base of the phyllode (except in subsp. hirtella , which has hirsute branchlets), thickened phyllode margins, leafless lower parts of the branchlets, or a combination of these features. Also, the phyllodes of D. nudiflora are often folded upwards longitudinally, and the pods are always much smaller (10–14 mm long) than in D. audax .

Figures

FIGURE 31. Daviesia audax. A. Flowering branchlet. B. Inflorescence (1-flowered). C. Pod. A, B from Crisp 6155; C from Crisp 5527. Drawn by A.L. Prowse. Adapted from Crisp (1995) with permission from CSIRO Publishing.