Daviesia dielsii E.Pritz.

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

121. Daviesia dielsii E.Pritz. in Diels & E. Pritzel (1904: 249), Crisp (1995: 1187). Type : ‘Hab. in distr. Avon pr. Moora in fruticetis arenosis apertis flor. m. Jun. (D. 3094)’ (B†). The type is missing, presumably destroyed in the Berlin herbarium during the Second World War ( Hiepko 1987). Neotype (Crisp 1995: 1187): Western Australia, Darling , N of Moora , C. Chapman (8)77, 1 June 1977 (CBG); isoneotype: K, PERTH

Intricate shrubs, to 1 m high and 1.5 m broad, retrorsely hirsute to minutely so (or glabrescent), occasionally glaucous. Root anatomy unknown. Branchlets diverging at 45–90°, terete, obscurely ribbed (ribs somewhat sharp), occasionally subspinescent. Phyllodes rather crowded, diverging at ca. 45°, vertically compressed, obliquely obovate to broadly so, or subulate, adaxial margin ± dilated distally, apex somewhat deflexed, acuminate, pungent, base truncate, articulate, 2–4(–7) × 1–2.5(–5) mm, minutely scabrous or tomentose, glabrescent, thick and robust;

266 • Phytotaxa 300 (1) © 2017 Magnolia Press

CRISP ET AL.

A MONOGRAPH OF DAVIESIA

Phytotaxa 300 (1) © 2017 Magnolia Press • 267 venation longitudinal, raised, prominent when dry. Unit inflorescences solitary in the axils, 1-flowered; peduncle nil; subtending bracts clustered at the base of the pedicel, ascending to spreading, oblong, tips fimbriate, ca. 0.5–1 mm long. Pedicel gently thickening towards the apex, 1.5–5 mm long. Calyx 2–2.75 mm long including the 0.5– 0.75 mm receptacle; upper 2 lobes united into a truncate lip, <0.5 mm long; lower 3 lobes triangular, ca. 0.5 mm long. Corolla : standard transversely elliptic to obovate, emarginate, 5.5–7 × 5.5–7 mm including the 1–1.25 mm claw, with 2 calli at the base of the lamina (sometimes obscure), yellow with a dark red centre; wings elliptic with a rounded apex, auriculate (with auricles occasionally hooked), 6–7 × 2–2.25 mm including the 1.5–2 mm claw, maroon; keel half broadly ovate with an acicular beak, saccate, 6.5–7.5 × 1.5–1.75 mm including the 3–3.5 mm claw, red. Stamens slightly dimorphic: inner whorl of 5 with longer, terete filaments and shorter, rounder anthers; outer whorl of 5 with shorter, broader, compressed filaments and longer, slender anthers; filaments cohering; anthers all 2-celled. Pod obliquely shallowly obtriangular with an acute apex, turgid, 11–13 × 7–9 mm; upper suture slightly sigmoid to curved upwards; lower suture acute. Seed not seen. ( Fig. 122 ).

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

Distribution:— Western Australia, restricted to the Dalwallinu–Moora–Three Springs area, north of Perth.

Habitat:— Gravelly, sandy loam over clay, clayey sand or gravelly laterite along disturbed roadsides in kwongan heath with Callitris or Allocasuarina .

Conservation status:— National: Endangered. WA: Endangered, Declared Rare Flora.

Selected specimens (18 examined):— Approximate locality data are given because the species is rare. WESTERN AUSTRALIA: Irwin: Near Marchagee, 30°S, 116°E, C . Chapman (7)77, 29 May 1977 ( CBG); ibid., C . Chapman (33)77, 22 July 1977 ( CBG, PERTH); ibid., M . D. Crisp 5471, 25 January 1979 ( CBG, PERTH); E of Watheroo , 30°20’S, 116°20’E, M . D. Crisp 6498, 16 July 1980 ( AD, CBG, PERTH). Darling : N of Moora, 30°30’S, 116°E, D. J . E . Whibley 4886, 2 November 1974 ( AD, PERTH); ibid., M . D. Tindale 2654, August 1973 ( NSW, PERTH); S of Koojan , 30°50’S, 116’ E, C . Chapman (92)77, 4 October 1977 ( CBG) .

Affinity:— Daviesia dielsii is similar to D. angulata , D. oxyclada and D. preissii . Daviesia angulata is glabrous and has sharp, angular ridges on the branchlets, whereas D. dielsii is merely ribbed. Daviesia preissii has a thickened articulation at the base of the phyllodes, whereas D. dielsii lacks a thickening at the articulation. The phyllodes of D. angulata , D. oxyclada and D. preisii are larger: those of D. angulata are 10–35(–40) mm long, those of D. oxyclada are 2–18 mm long and those of D. preisii are 10–40 mm long. Daviesia angulata has racemose, 2–4-flowered inflorescences and D. preisii has umbellate, 1- or 2-flowered inflorescences, where D. dielsii has a 1-flowered inflorescence lacking a peduncle. Both D. angulata and D. preissii have the upper 2 calyx lobes united higher than the lower 3 but not united into a truncate lip. Daviesia oxyclada also differs in being entirely glabrous, has mostly spinescent branchlets, and the outer part of the standard is orange or orange-red.

Variation:— Daviesia dielsii varies in the degree of hairiness. In the south, near Moora, the branchlets are less densely hairy and the phyllodes glabrescent.

Figures

FIGURE 122. Daviesia dielsii. A. Flowering branchlet. B. Phyllode with axillary 1-flowered inflorescence (floral parts except calyx removed). C. Pod. A from Chapman (33)77; B from Chapman s.n., Marchagee, 31 May 1979; C from Chapman (92)77. Drawn by B- J. Osborne.