Daviesia trigonophylla Meisner (1848: 213)

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

100. Daviesia trigonophylla Meisner (1848: 213) , Bentham (1864: 87), Crisp (1995: 1239). Type: ‘Swan River, Drummond coll. III. No. 77.’ Holotype: BM; isotypes: G (3 sheets), K (2 sheets), OXF, P, W

Compact to bushy, scabrous shrubs, to 1 m tall. Root anatomy unknown. Branchlets ascending (rarely divaricate), 3–4-winged with the decurrent phyllode bases, becoming angular and ribbed as the wings narrow downwards. Phyllodes scattered, curving outward at 60–90°, trigonous in transection with an elliptic or ovate, somewhat folded upwards, adaxial lamina and a vertical abaxial decurrent wing, apically acuminate, pungent, 3–15 × 2–7 mm, mostly hispid all over, occasionally with hairs only on the margins, green. Unit inflorescences 1 per axil, racemose, 2(3)-flowered; peduncle ca. 0.5 mm long; rachis 0.5–2 mm long; subtending bracts ascending, oblong, keeled, ca. 0.5 mm long. Pedicels 1.5–2.5 mm long. Calyx 3–3.5 mm long including the 0.75–1 mm receptacle; lobes 0.5–1 mm long; upper 2 lobes united into a broad, truncate lip; lower 3 lobes triangular, recurved. Corolla : standard transversely elliptic to broadly so, emarginate, cordate, 5.5–8 × 6–9.5 mm including the 1.5–2 mm claw, outer two-thirds orange, inner third dark red with 2 pale yellow spots; wings very broadly obovate to transversely so with a rounded, incurved apex, slightly overlapping the keel, auriculate, with a small lobe on the abaxial margin, 5–6 × 3.5–4 mm including the 1.5–2 mm claw, maroon; keel half transversely elliptic, obtuse, auriculate, saccate, 4–5 × 2 mm including the 1.5–2 mm claw, maroon. Stamens moderately dimorphic: inner whorl of 5 with longer, slender, terete filaments and slightly shorter, versatile anthers with confluent thecae; outer whorl of 5 with shorter, broader, compressed filaments and slightly longer, 2-celled, basifixed anthers; filaments cohering; vexillary stamen with a channelled filament forming an apical pedestal subtending the anther. Pod obliquely shallowly obtriangular, acute to scarcely obtuse, turgid, 11–13 × 8.5–9 mm; upper suture swept upwards; lower suture acute but broadly rounded. Seed not seen. ( Fig. 101 ).

226 • Phytotaxa 300 (1) © 2017 Magnolia Press

CRISP ET AL.

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

Distribution:— Western Australia, Stirling Range to the adjacent coast.

Habitat:— Grows on stony, skeletal soil in diverse tall closed-heath, or mallee-heath dominated by Eucalyptus spp.

Selected specimens (13 examined):— WESTERN AUSTRALIA. Eyre: Due N of Ellen Peak and due W of Moir Hill, 34°19’S, 118°20’E, M . D. Crisp 8954 & W . Keys, 15 October 1996 ( CBG, PERTH); Stirling Range, 24 km W of Chester Pass, on road to Red Gum Pass , 34°26’S, 117°55’E, T. B . Muir 3904, 28 September 1966 ( MEL); Stirling Range, 10 km along East Pillenorup Track from Chester Pass Road, 34°26’S, 118°10’E, M . D. Crisp 5260, 18 January 1979 ( CBG, PERTH); Stirling Range , 2 km SE of Wedge Hill, 34°26’S, 118°11’E, M .D. Crisp 6118, et

A MONOGRAPH OF DAVIESIA

Phytotaxa 300 (1) © 2017 Magnolia Press • 227 al., 24 September 1979 ( CBG, K, MEL); Stirling Range Drive, at base of Mondurup Peak track, 34°24’S, 117°49’E, M . D. Crisp 8494 & W . Keys, 25 September 1993 ( CBG, GAUBA, PERTH, UWA) .

Affinity:— Daviesia trigonophylla is immediately recognised by its triquetrous, strongly decurrent phyllodes. It is superficially similar to D. decipiens , which is easily distinguished by its strictly vertically flattened phyllodes and absence of scabrous indumentum.

Figures

FIGURE 101. Daviesia trigonophylla. A. Flowering branchlet. B. Inflorescence. C. Pod. A, B from Crisp 6118; C from Crisp 5260. Drawn by A.L. Prowse.