Daviesia nudiflora Meisner (1844: 53)

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

40. Daviesia nudiflora Meisner (1844: 53) , Bentham (1864: 79), Crisp (1987a: 251), Crisp (1995: 1214). Type: ‘In arenosis sylvae prope Kei-er-mu-lu v. Monger’s lake (Perth) d. 16. July 1839. Herb. Preiss. no. 1143. (Drummond n. 226).’ Lectotype (Crisp 1995: 1214): Preiss 1143 ( NY, ex Herb. Meisn.) ; isolectotype: BR, FI-W, G (2 sheets), LD, MEL (3 sheets), MO, P (2 sheets), PERTH, S, W (2 sheets) . Syntype: Drummond 226 ( BM, ex Herb. Shuttleworth) ; isosyntypes: G (2 sheets), K (2 sheets), MEL, OXF, P (2 sheets), W (2 sheets)

Daviesia drummondii Meisner (1844: 53) , Bentham (1864: 80). Type: ‘Swan River, James Drummond n. 227.’ Holotype: BM; isotypes: G (3 sheets), K (2 sheets), MEL, OXF, P (2 sheets), PERTH, W (2 sheets).

Bushy shrubs to 2.5 m high, muricate or rarely hispidulous on branchlets ( subsp. hirtella ). Root anatomy normal (unistelar). Branchlets ± angular, ribbed. Phyllodes either crowded at or near to branchlet apex and reduced to scales at lower nodes, or extending the full length of the branchlet, diverging at 0–90°, ovate to elliptic (or narrowly so) or oblong, flat or partially folded upwards along the midrib, apically acuminate or cuspidate, pungent, base tapered to cordate, inarticulate and decurrent (but nerves thickened at the node in subsp. hirtella ), 4–50 × 2–18

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CRISP ET AL.

mm; scale leaves subulate, rigid, keeled, 1–4 mm long. Unit inflorescences 1 or 2 per axil of phyllodes or scale-leaves, 1-flowered; peduncle 0.5–2 mm long; bracts forming an involucre at the base of the peduncle, spreading and undulating to hooded and channelled, keeled or not, fimbriate, sometimes 3-lobed and lacerated (see below). Pedicels thickening towards the apex, 2–7 mm long. Calyx 3–4.5 mm long including the 1–1.5 mm receptacle, adaxially ventricose; upper 2 lobes united in a truncate lip with outcurved lobes, ca. 1 mm long; lower 3 lobes triangular, ca. 1 mm long. Corolla : standard ovate or elliptic (to broadly so) or transversely broadly elliptic, emarginate, 7–12 × 7–11 mm including the 1–2.5 mm claw, with 2 calli at the base of the lamina, yellow to orange with a red to brown centre; wings elliptic with a rounded, incurved apex, overlapping to enclose the apex of the keel, auriculate, with the long, slender auricles ± as long as the claw and hooked at the end, 7–10 × 2–4 mm including the 2–4 mm claw, red to deeply so or rarely brown; keel half transversely obovate to broadly so, apically acicular, auriculate or not, saccate, 6–10 × 2.5–3 mm including the 3–5 mm claw, red to deeply so or rarely brown. Stamens strongly dimorphic: inner whorl of 5 with longer, slender filaments and shorter, rounder, versatile anthers with confluent thecae; outer whorl of 5 with shorter, broader, compressed filaments and longer, slender, basifixed, 2-celled anthers; vexillary filament slender, tapering towards the apex; filaments cohering. Pod obliquely shallowly obtriangular, acuminate, somewhat compressed, 10–14 × 5–9 mm; upper suture sigmoid; lower suture acute and sharply to broadly curved. Seed 4–5.5 mm long, 2.5–3.5 mm wide, 1.7–2 mm thick, dark brown with no mottling to light brown or grey with black mottling; aril 1.8–3 mm long. ( Figs 38 , 39 ).

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

Distribution:— Western Australia, widespread in the northern half of the wheatbelt from Kalbarri southward as far as the Lake Grace region; also, disjunct populations near Bunbury and near Southern Cross.

Habitat:— Grows mostly on sandy soils, sometimes clayey, gravelly or loamy, in undulating or flat areas, in mallee-heathland dominated by Eucalyptus and Allocasuarina spp. , with shrubs of Myrtaceae and Proteaceae dominant in the understorey.

Affinity:— Daviesia nudiflora bears a resemblance to D. abnormis , which also has phyllodes produced only near the branchlet apex but differs by being very hirsute and having corky bark; also, the phyllodes more or less clasp the stem, the inflorescences are cryptic and the standard is paler, predominantly yellow, and lacks calli. Daviesia audax is also similar to D. nudiflora but the growth habit is erect, the phyllodes are never folded upwards longitudinally, have a thickened articulation at the base and are present all the way along the branchlets, the calyx is not ventricose, and the pods are always much larger (18–25 mm long).

Variation:— Daviesia nudiflora is highly variable in the arrangement and morphology of the phyllodes, although floral and fruit characters are nearly constant. The involucral bracts in this species show much variation in form. The upper bracts in the cluster are longer, more or less spreading or even reflexed, adaxially concave to hooded and channelled, keeled or not and conspicuously fimbriate. The lower bracts in the involucre are more appressed, triangular and shorter, sometimes with a serrate margin. Sometimes the upper involucral bracts tend to be trilobed or lacerated. Some subspecies ( subsp. hirtella and near-coastal populations of subsp. nudiflora ) have bracts with spreading, undulate, slightly fimbriate (not lacerate) margins and are only slightly incurved at the apex (more so in subsp. hirtella but the bracts are not hooded). In other subspecies ( subsp. amplectens , drummondii and nudiflora (inland populations), the bracts are strongly incurved and hooded at the apex, so that the bract is channelled, and they are also strongly fimbriate and serrate to lacerate or even trilobed.

Figures

FIGURE 38. Daviesia nudiflora, Part 1, comparing two of four subspecies. Daviesia nudiflora subsp. nudiflora. A. Flowering branchlet. B. Inflorescence (1-flowered). C. Pod. Daviesia nudiflora subsp. amplectens. D. Flowering branchlet. E. Single-flowered inflorescence in bud. F. Pod. A, B from Crisp 6471; C from Maiden s.n. (NSW 34924); D, E from Crisp 6536 (type); F from Crisp 6432. Drawn by B-J. Osborne (A–C) and A.L. Prowse (D–F)

FIGURE 39. Daviesia nudiflora, Part 2, comparing branchlets of all four subspecies. A. Daviesia nudiflora subsp. amplectens (from Crisp 6690). B–D. Daviesia nudiflora subsp. drummondii. (B from Drummond 133, type of synonym D. nudiflora var. lanceolata; C from Drummond coll. II no. 227, type of basionym D. drummondii; D from Crisp 6203). E. Daviesia nudiflora subsp. hirtella (E from George 2599). F, G. Daviesia nudiflora subsp. nudiflora (F from Phillips WA/68-723; G from Crisp 6531). Drawn by B-J. Osborne. Adapted from Crisp (1995) with permission from CSIRO Publishing.