Daviesia elongata Bentham (1864: 74)

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

20. Daviesia elongata Bentham (1864: 74) , (Crisp 1995: 1189), Wheeler et al. (2002: 743). Type: ‘W. Australia, Drummond, 2nd Coll. n. 136.’ Lectotype (Crisp 1995: 1189): K (ex Herb. Hooker, annotated ‘Negative no. Kew 911’); isolectotype: BM, E, G, K (ex LINN), K (ex Herb. Bentham), LD, MEL, P, PERTH, U, W

Spreading or sprawling shrubs with many tangled stems from a common rootstock, 0.5–1 m high and up to 1 m broad, glabrous, glaucous. Root anatomy normal (unistelar). Branchlets compressed-angular to tetragonous, prominently ribbed. Phyllodes scattered, erect, narrowly obovate or elliptic to linear, tapering to the acute apex and also to the inarticulate decurrent base, 40–170 × 4–15 mm, green; midrib prominent, lateral venation obscure. Unit inflorescences 1 per axil, racemose, 2- or 3-flowered; peduncle 8–12 mm long; rachis 1–2 mm long; subtending bracts linear, leaf-like, ca. equal in length to flowers at anthesis, enlarging to ca. 20 mm long in fruit; venation prominently reticulate; barren bracts scattered along peduncle, appressed, triangular, ca. 1 mm long. Pedicels 2– 7.5 mm long. Calyx with the upper 2 lobes united into an emarginate lip, broadly rounded, recurved and touching the adjacent lower lobe; lower 3 lobes triangular, ca. 0.75 mm long. Corolla : standard transversely elliptic, emarginate, 10–11.5 × 8–12 mm including the 3–4 mm claw, rich yellow to yellow-orange with a red ring around the oblong yellow centre; wings obovate, rounded and incurved at apex and enclosing the much shorter keel, auriculate, 8.5–11 × 3–4.5 mm including the ca. 3 mm claw, maroon, fading to orange-yellow at the tips; keel half transversely very broadly obovate, acute, saccate, ca. 6.5 × 2–3 mm including the 2.5–3 mm claw, maroon. Stamens strongly dimorphic: inner whorl of 5 with longer, slender, 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 cohering. Pod obliquely shallowly obtriangular, compressed, acuminate, 15–17 × 7–8 mm; upper suture slightly sigmoid; lower suture acute. Seed ellipsoid, ca. 4 mm long, 2.5 mm broad, 1.5 mm thick, light brown; aril ca. 2.5 mm long. ( Fig. 21A–C ).

Flowering period:— September to January. Fruiting period: October to January.

Distribution:— Known only from the Busselton area, Western Australia.

Habitat:— Grows in pale brown sand on flat terrain in heath understorey of open forest dominated by Eucalyptus marginata and Corymbia calophylla .

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

Additional specimens examined: — Approximate locality data given because the species is rare. WESTERN AUSTRALIA. Darling : SW of Busselton, 33°40’S, 115°10’E, R . D. Royce 4688, 25 October 1953 ( PERTH); ibid., C. A . Gardner 5572, 12 September 1940 ( PERTH); ibid., M . D. Crisp 5360, 21 January 1979 ( AD, CBG, K, MEL, MO, NSW, PERTH); WA, J . Drummond 44 ( MEL 78035 ) .

Affinity:— Daviesia implexa was previously included as a subspecies of D. elongata but differs qualitatively in several characters including pruinose vegetative parts, twisted and apically hooked phyllodes, much smaller (≤ 2 mm long) subtending bracts that do not enlarge in fruit, and in the upper 2 calyx lobes. In D. elongata these lobes are broadly rounded and recurved, touching the adjacent lower lobes, but D. implexa has a broad, truncate lip.

Daviesia costata , D. longifolia and D. pauciflora are similar in their straggling, tangled growth habit, and in

A MONOGRAPH OF DAVIESIA

Phytotaxa 300 (1) © 2017 Magnolia Press • 63 having linear decurrent phyllodes, but all three species have small (≤ 2 mm long) non-enlarging bracts, a calyx with ± equal lobes, and individual differences as follows. Daviesia costata differs in having a smaller calyx (3.5–5 mm long, including receptacle) with ten conspicuous ribs. Daviesia longifolia differs mainly in having a larger inflorescence (4–15-flowered) and a generally longer peduncle and rachis that are (4–) 10–17 mm and (0–)6–28(– 150) mm long respectively, and a smaller calyx (3–4 mm long, including the receptacle). Daviesia pauciflora has much longer (to 400 mm long) and narrower (to 1.5 mm broad) phyllodes than D. elongata , and often has a pair of flowers at the apex of the inflorescence, unlike D. elongata . Also, D. pauciflora has an auriculate keel, whereas that of D. elongata is vestigial.

Figures

FIGURE 21. Daviesia elongata. A. Flowering branchlet. B. Infructescence. C. Pod. Daviesia implexa. D. Flowering branchlet. E. Infructescence. A from Royce 4688; B, C from Crisp 5360; D, E from Crisp 5540. Drawn by A.L. Prowse. Adapted from Crisp (1995) with permission from CSIRO Publishing.