Daviesia costata Cheel (1920: 35)

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

18. Daviesia costata Cheel (1920: 35) , Crisp (1987a: 248), Crisp (1991a: 252), Crisp (1995: 1183), Wheeler et al. (2002: 743). Type: ‘This new plant was first collected at Queenswood [sic], on the Preston Valley Railway, by Mr. Max Koch in October, 1910; and bears the no. 2041. It has since been collected on sandy places in open jarrah forests, six miles from Donnybrook, in October, 1912, by the same collector. 6 miles from Donnybrook, M. Koch, October 1912 ’ (NSW 34717). Lectotype ( Crisp 1991a: 252): Queenwood, M. Koch, October 1910 (NSW 34958, partly); isolectotype: BM, BRI, CANB, G (2 sheets), K (2 sheets), MEL 77996–8, MO, NSW 34718–9 & 34958 (partly), US

Straggling, sometimes bushy, multi-stemmed shrubs, to 0.7 m high and 1.3 m broad, glabrous. Root anatomy normal (unistelar). Branchlets rather lax, angular, ribbed. Phyllodes scattered, ascending, linear, rarely appearing terete (Blackall 3266, Taylor 2231), acute to rounded at apex, mucronate, tapered to the inarticulate decurrent base, 1–300 × 0.5–10 mm, pale grey-green, much reduced in size and often recurved, sometimes to scales, toward the apex of flowering branchlets; midrib prominent with 2 thickened marginal nerves and oblique lateral venation in phyllodes broader than 2.5 mm; phyllodes tetragonous but appearing terete when <2.5 mm wide. Unit inflorescences 1 or more in upper axils, condensed racemes (or appearing paniculate by reduction of phyllodes to scales), (1–)3–8(–14)-flowered, with (0–)2–6 flowers forming a partial umbel at apex of rachis; peduncle 7–30(– 60) mm long; rachis from almost nil to 100 mm long; subtending bracts somewhat spreading, ovate to obovate, keeled, ca. 1.5 mm long, viscid. Pedicels 3–11 mm long, usually hooked at apex. Calyx 3.5–5 mm long including the 1–2 mm stipe-like receptacle to which it is contracted, thick in texture, with 10 prominent ribs extending up from the base, 5 ending at the tips of the lobes and 5 not quite reaching the sinuses, the latter 5 sometimes forked at the upper ends, ribs and apices of the lobes tinged purple; all 5 lobes equal, transversely broadly triangular, ca. 0.5 mm long. Corolla : standard depressed-ovate, deeply emarginate and almost bilobed, cordate, with a small auricle on either side and 2 raised calli at the base of the lamina, ca. 6 × 10 mm including the ca. 1 mm claw, yellow with a dark red infusion towards the centre and an intensely yellow cuneate central marking; wings obovate with a rounded apex, incurved but hardly overlapping, auriculate, ca. 5 × 2.5 mm including the ca. 1 mm claw, dark red; keel half very broadly ovate with an acute apex, saccate, scarcely auriculate, ca. 5 × 2 mm including the ca. 1.5 mm claw, dark red. Stamens strongly dimorphic: inner whorl of 5 with filaments slightly to very compressed and globose, anthers subversatile with confluent thecae; outer whorl of 5 with very compressed filaments and basifixed, ovoid, 2-celled anthers; filaments free. Pod obliquely shallowly obtriangular, compressed, acute, with somewhat thickened sutures, 10–15 × 5–7 mm, rather thin-walled; upper suture sigmoid; lower suture acute. Seed not seen. ( Fig. 20 ).

Flowering period:— Mainly September and October, but also from July to February. Fruiting period: Apparently in summer. Seed set appears to be poor.

Distribution:— Western Australia, throughout the Darling Range from the Toodyay–Bindoon area south to the vicinity of the Blackwood and Gordon Rivers; also extending to the wheatbelt east of Perth towards Quairading and Corrigin and south to near Katanning.

Habitat:— Occurring on flat or sloping sites, in sand, or more usually, gravelly clay-loam derived from laterite. Associated vegetation is usually open forest dominated by Eucalyptus marginata and Corymbia calophylla , also woodland dominated by E. wandoo or E. accedens Fitzgerald (1904: 21) , or tall heath with Grevillea and other large shrubs.

A MONOGRAPH OF DAVIESIA

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Selected specimens (24 examined):— WESTERN AUSTRALIA. Darling: 10 km from Donnybrook towards Mumballup, 0.8 km E of Queenwood , 33°33’S, 115°55’E, M . D. Crisp 5366, 21 January 1979 ( AD, CBG, K, MEL, MO, PERTH); 1 km SE of North Bannister , 32°35’S, 116°28’E, J . Taylor 2135 & P . Ollerenshaw, 22 September 1983 ( AD, CBG, MEL, PERTH); Logue Brook Dam beyond Saddle Dam , 32°59’S, 115°59’E, T. A .

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CRISP ET AL.

Halliday 211, 5 December 1974 ( AK, CANB, PERTH); W. E . Blackall 3266 ( PERTH); Collie , 33°22’S, 116°09’E, L. W. J . Dodd 6, February 1968 ( PERTH); 6.4–8 km SE of Waroona , 32°51’S, 115°55’E, A. S . George 6860, 15 October 1965 ( AD, CANB, PERTH); Mt Saddleback , 32°58’S, 116°27’E, A . Morrison s.n., 15 November 1904 ( PERTH 2778742 ); Plains south of the Blackwood River , 34°09’S, 115°15’E, R .D. Royce 2950, 24 October 1948 ( PERTH) . Avon: 27 km from Quairading towards Corrigin, 32°06’S, 117°34’E, J . Taylor 2231 & P . Ollerenshaw, 25 September 1983 ( CBG, MEL, PERTH) .

Affinity:— Daviesia costata is very similar to D. longifolia , D. pauciflora and D. implexa . It can be most readily distinguished from all these species by the ten prominent ribs on the calyx, after which it was named ( Cheel 1920). Daviesia implexa differs in having a larger calyx (5.5–7 mm long, including receptacle) without conspicuous ribs, and the upper two lobes are united into a truncate, emarginate lip. The calyx of D. pauciflora has obscure ribs at best, while that of D. longifolia has five (rarely ten) rather obscure ribs at best and also differs in the upper two lobes, which are recurved and larger than the lower three. Additional differences between D. costata and D. pauciflora are given under the latter. Daviesia longifolia and D. costata are superficially very alike and can be difficult to distinguish, especially when the phyllodes are narrow. Specimens with broader phyllodes (> 2.5 mm broad) differ in the venation. In D. longifolia , such phyllodes have two or more secondary longitudinal ribs along each face in addition to the midrib and marginal ribs. In D. costata , phyllodes when broad have raised venation but it runs obliquely to the margins. Even when the phyllodes are less than 2.5 mm broad, it is still possible to distinguish them. Those of D. costata become tetragonous in section with one rib at each angle and no other visible venation, whereas those of D. longifolia become rounded to terete (rarely oblong) in section and have six or more parallel ribs. Specimens of D. costata with extremely narrow phyllodes (0.5–1 mm broad) that appear terete but which are actually tetragonous are apparently localised near Quairading (Blackall 3266, Taylor 2231). An additional character of D. longifolia that distinguishes it from D. costata is the truncate base of the standard.

Figures

FIGURE 20. Daviesia costata. A. Flowering branchlet. B. Long phyllode. C. Inflorescence. D. Flower with bracts. E. Calyx opened out, upper lobes at left. F. Standard. G. Wings. H. Keel. I. Same, opened out. J. Pod. A from Morrison s.n. (PERTH 2778742); B from Dodd 6; C from Crisp 5366; D–I from Taylor 2135; J from Koch s.n. (type: NSW 34718). Drawn by B-J. Osborne and D. Fortescue. Adapted from Crisp (1991a) with permission from CSIRO Publishing.