Daviesia oxyclada Crisp (1995: 1217)

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

120. Daviesia oxyclada Crisp (1995: 1217) . Type: Western Australia, Irwin, 43 km W of Winchester , 29°49’S, 115°33’E, C. Chapman (5)76, 23 May 1976. Holotype: CBG; isotypes: K, MEL, PERTH

Divaricate shrubs ca. 0.6 m high, glabrous, dark green to pruinose. Root anatomy unknown. Branchlets diverging at ca. 45°, terete, smooth when fresh, ribbed when dry, spinescent. Phyllodes scattered, diverging at ca. 45°, obliquely obtriangular (occasionally reduced to scales), vertically compressed, with the adaxial margin dilated into an obtuse lobe, contracted at the apex into a deflexed pungent point, base articulate and easily detached, (2–)5–10(– 18) × 1–4(–8) mm, with 2 or more irregular raised longitudinal nerves (prominent when dry); upper phyllodes (or rarely all, Borger CH 267-1 3) usually recurved and unlobed but merely asymmetric. Unit inflorescences 1 per axil, racemose, 1- or 2-flowered; peduncle ± nil; subtending bracts appressed to the pedicel, oblong, ca. 1 mm long. Pedicels 0.5–2 mm long. Calyx 1.5–2 mm long including the ca. 0.5 mm receptacle; lobes little more than apiculate teeth, upper 2 ± united; receptacle abruptly contracted to pedicel. Corolla : standard very broadly obovate, emarginate, 6.5–8 × 6–8 mm including the ca. 1 mm claw, with 2 calli at the base of the lamina, yellow, orange-yellow or deep orange surrounding a dark red centre; wings narrowly obovate, falcate, incurved and overlapping to enclose keel at apex, with uncinate auricles, 6–7.5 × 2–2.5 mm including the ca. 1.5 mm claw, red; keel half very broadly elliptic, bluntly beaked, sharply incurved through 90°, 6.5–7 × 1.5–2 mm including the 2.5–3.5 mm claw, red. Stamens weakly dimorphic: inner whorl of 5 with longer filaments and shorter, versatile anthers; outer whorl of 5 with shorter filaments and longer, basifixed anthers; filaments all compressed, firmly cohering into a tube except upper quarter, very broad towards base; anthers all 2-celled. Pod obliquely shallowly obtriangular, turgid, sharply beaked, distally indented, 9–12 × 7–8 mm, purplish pruinose; upper suture undulating; lower suture acute. Seed not seen. ( Fig. 121 ).

Flowering period:— May to August. Fruiting period: August and September.

Distribution:— Western Australia, north of Perth from Moora through Eneabba–Carnamah to Mingenew.

Habitat:— Grows in sandy, gravelly (often clayey) soils or occasionally in sandy loam, in heath (kwongan).

Selected specimens (27 examined):—WESTERN AUSTRALIA. Irwin: 2 km SW of Eneabba , near railway crossing, 29°50’S, 115°15’E , C. Chapman (3)78, 9 July 1978 ( CBG, PERTH); 20.5 km from Three Springs on Eneabba road, 29°35’S, 115°35’E , C. Chapman (11)77, 19 June 1977 ( CBG); creek to Jennings’ settling pond, near Eneabba, 29°50’S, 115°15’E , C. Chapman (14)77, 19 June 1977 ( CBG, NSW); 22 km N of Badgingarra , A. S. George 6743, 13 August 1965 ( PERTH); 17 km W of Winchester along road to Eneabba , 29°48’S, 115°46’E , M. D. Crisp 6478, 15 July 1980 ( CBG); Eneabba , 29°49’S, 115°16’E , C. E. Woolcock D19, 19 July 1981 ( CBG); 22 km W of Winchester , 29°48’S, 115°42’E , C. Chapman (10)78, 29 July 1978 ( CBG, PERTH); 8.5 km W of Road 36 (Willis Road ) on Winchester–Eneabba Road , C. Chapman (77)77, 18 September 1977 ( CBG) ; S side of Arrowsmith River , 29°28’S, 115°30’E , J. Borger CH 267-13, 26 July 2005 ( PERTH) .

Affinity:— This species belongs to a natural group typified by D. incrassata , with which it shares turgid pods, a distinctive calyx, an incurved beaked keel and weakly dimorphic stamens (see under D. chapmanii ). Within the D. incrassata group, it appears most similar to D. dielsii and D. physodes with respect to phyllode morphology. The most diagnostic feature of D. dielsii is the short, curved hairs covering the branchlets (sometimes sparsely) and frequently the phyllodes, too; additional distinctions from D. oxyclada are the often non-spinescent branchlets and the smaller phyllodes: 2–4(5) mm long, 1–3 mm broad. Otherwise, these species are very similar and easily confused. Daviesia physodes differs in having non-spinescent branchlets, larger phyllodes (10–55 mm long), 2–4- flowered racemes and larger flowers (e.g. standard 7–8 mm broad).

Figures

FIGURE 121. Daviesia oxyclada. A. Flowering branchlet. B. Phyllode. C. Inflorescence. D. Pod. A from Chapman (11)77; B from Chapman (14)77; C from Crisp 6478; D from Chapman (77)77. Drawn by A.L. Prowse. Adapted from Crisp (1995) with permission from CSIRO Publishing.