Daviesia scoparia Crisp (1995: 1235)

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

68. Daviesia scoparia Crisp (1995: 1235) . Type: Western Australia, Roe, 5 km N of Borden , 34°02’S, 118°16’E, M. D. Crisp 6142, J. Taylor & R. Jackson, 25 September 1979. Holotype: CBG; isotypes: K, NSW, PERTH

Leafless, ‘broombush’ shrubs, to 2 m high, glabrous. Root anatomy normal (unistelar). Branchlets erect, terete, subspinescent, 0.75–1.25 mm diam., smooth when fresh, striate when dry, dull green. Phyllodes all reduced to scales. Unit inflorescences 1 per axil, racemose, 1–3(4)-flowered; peduncle 0.5–2 mm long; rachis 2–8 mm long; subtending bracts spreading, spathulate, very cupped, ca. 1 mm long, ≥ pedicels. Pedicels 0.5–1 mm long. Calyx 3–4 mm long including the ca. 1 mm receptacle; upper 2 lobes united in a truncate, emarginate lip, ca. 0.5 mm long; lower 3 lobes triangular, acute, ca. 0.5 mm long. Corolla : standard transversely elliptic, emarginate, ca. 6 × 7–8 mm including the 2 mm claw, yellow with a dark red-brown centre; wings spathulate, rounded and incurved at apex but not overlapping, slightly auriculate, ca. 5.5 × 2 mm including the 2 mm claw, maroon, fading to yellow at the tips; keel half transversely elliptic, scarcely acute, abaxially rugose, auriculate, saccate, 4–5 × 1.5–2.25 mm including the 1–1.75 mm claw, maroon. Stamens strongly dimorphic: inner whorl of 5 with longer, terete filaments and shorter, round, versatile anthers with confluent thecae; outer whorl of 5 with shorter, broader, compressed filaments and longer, oblong, basifixed, 2-celled anthers; filaments free. Pod obliquely shallowly obtriangular, obtuse, compressed, 6–7 × 4 mm, thin-walled, dark brown, upper suture markedly sigmoid; lower suture obtuse. Seed not seen. ( Fig. 68 ).

Flowering period:— September and October. Fruiting period: From September onwards.

Distribution:— Western Australia, widespread in the southern wheatbelt and mallee districts, from Corrigin, Katanning and the Stirling Range in the west, extending eastward to the Parmango Road area (NE of Condingup). Outlying populations occur north of the Great Eastern Highway, in the Koolyanobbing Range (e.g. Cockerton et al. WB 34862) and Helena and Aurora Ranges (fide M. Hislop).

Habitat:— Grows in gravelly, sandy or clay soils in mallee-heath or woodland dominated by Eucalyptus spp.

Selected specimens (27 examined):— WESTERN AUSTRALIA. Avon: 32 km from Katanning along road to Nyabing, 33°38’S, 117°55’E, M . D. Crisp 5196, 16 January 1979 ( CBG). Coolgardie : 11 km SE of Koolyanobbing, 30°52’S, 119°36’E, G . Cockerton & S . Regan WB 34862 ( PERTH). Roe: E of Hyden, between Lake Cronin and Painted Cliffs , A . Kessel 485, 25 October 1966 ( PERTH); 21 km NW of Holt Rock P. O . on track to Hyden , 32°32’S, 119°16’E, L . Haegi 1216, 5 October 1976 ( AD, CANB, PERTH); 23 km NNW of Mt Buraminya , 33°02’S, 123°05’E, W. R . Archer 2311913, 23 November 1991 ( CANB, MEL, PERTH); ibid., W. R . Archer 2909913, 29 September 1991 ( AD, CANB, HO, MEL, PERTH). Eyre : 21 km W of Ongerup, 34°01’S, 118°16’E, K . Newbey 552, 1 October 1962 ( PERTH); 75 km NE of Ravensthorpe, 5 km S of Dunn Swamp , 33°13’S, 120°43’E, M . D. Crisp 6048 et al., 21 September 1979 ( AD, CBG, NSW, PERTH); ca. 80 km N of Esperance , 33°13’S, 121°43’E, R. H . Kuchel 1717, 12 September 1964 ( AD, B, L, G, NY, MO, SI) .

Affinity:— Of the few species in the genus with leafless, terete branchlets, D. scoparia is most similar to D. aphylla and these taxa have been confused under the latter name. Moreover, they are sympatric over a broad area of southern Western Australia. However, D. aphylla is seldom completely leafless—usually it has a few widely spreading, terete, robust, pungent phyllodes near the branchlet apex. When leafless, D. aphylla may be distinguished by its divaricate, open habit, more robust branchlets (1.5–2.5 mm diam.) which are wrinkled rather than striate in the dry state, racemes usually with four or more flowers and smaller bracts (ca. 0.5 mm long, ≤ pedicels).

A MONOGRAPH OF DAVIESIA

Phytotaxa 300 (1) © 2017 Magnolia Press • 157 158 • Phytotaxa 300 (1) © 2017 Magnolia Press

CRISP ET AL.

Figures

FIGURE 68. Daviesia scoparia. A. Flowering branchlet. B. Inflorescence. C. Pod. A from Kuchel 1717; B from Crisp 6142 (type); C from Crisp 5196. Drawn by B.J. Osborne. Adapted from Crisp (1995) with permission from CSIRO Publishing.