Daviesia implexa (Crisp) Crisp

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

19. Daviesia implexa (Crisp) Crisp , comb. & stat. nov.

Basionym: Daviesia elongata Bentham (1864: 74) subsp. implexa Crisp (1995: 1191) . Type [approximate locality data given because the species is rare]: Western Australia, Roe , E of Lake Grace , 33°10’S, 118°30’E, J. Taylor 2264 & P. Ollerenshaw , 25 September 1983. Holotype: CBG; isotypes: K, MEL, PERTH.

Hummocky shrubs to 1 m high and 2 m wide, multi-stemmed, tangled and straggling, glabrous, pruinose. Branchlets angular with prominent ridges or narrow wings. Root anatomy with anomalous secondary thickening (cord type). Phyllodes scattered, ascending, linear, twisted into a loose spiral (1–3 turns), recurved to hooked at the apex, basally inarticulate and decurrent, 5–100 × 2–5 mm, with a prominent midrib and thickened, waxy margins. Unit inflorescences racemose, 2- or 3-flowered; subtending bracts appressed, subulate, 1.5–2 mm long. Pedicels 2.5–6 mm long. Calyx slightly ribbed; upper 2 lobes united into a truncate, notched lip; lower lobes acute. Corolla : standard transversely elliptic, emarginate, 10–11.5 × 8–12 mm including the 3–4 mm claw, yellow or apricot with a narrow red-brown arc surrounding the yellow-green central circle, and a vertical yellow stripe at the centre of the abaxial surface; wings obovate, rounded and incurved at apex, enclosing the much shorter keel, auriculate, 8.5–11 × 3–4.5 mm including the ca. 3 mm claw, red with orange margins; keel half transversely very broadly obovate, acute, saccate, ca. 6.5 × 2–3 mm including the 2.5–3 mm claw, yellow. 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 mm long including a long-acuminate beak, 7–8 mm broad; 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. 21D, E ).

Flowering period:— September to January. Fruiting period: December and January.

Distribution:— Western Australia, south-eastern wheatbelt from Kulin to east of Hyden.

Habitat:— Grows in gravelly sand in heath (kwongan) dominated e.g. by Allocasuarina .

Conservation status:— National: Not listed. WA: Priority 3, possibly threatened or near-threatened but not yet adequately surveyed.

A MONOGRAPH OF DAVIESIA

Phytotaxa 300 (1) © 2017 Magnolia Press • 61 62 • Phytotaxa 300 (1) © 2017 Magnolia Press

CRISP ET AL.

Selected specimens (16 examined):— Approximate locality data given because the species is rare. WESTERN AUSTRALIA. Roe: Near Newdegate , 33°10’S, 119°’ E, W . E . Blackall 1281, 7 November 1931 ( PERTH); N of Lake Grace township , 32°40’S, 118°20’E, P . Wilson 3430, 21 September 1964 ( AD, CANB); E of Newdegate , 33°10’S, 119°10’E, J . M . Taylor 2293 & P . Ollerenshaw, 26 September 1983 ( CBG, MEL); Lake Grace , 33°10’S, 118°30’E, W . E . Blackall 3178, September 1933 ( PERTH); W of Lake Grace , 33°10’S, 118°20’E, M . D. Crisp 5540, 28 January 1979 ( AD, CBG, K, MEL, MO, PERTH) .

Affinity:— Although previously included as a subspecies of D. elongata , this taxon differs sharply in the size of the bracts, the twisted and apically hooked phyllodes, 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 implexa could be confused with D. longifolia , D. pauciflora or D. costata because all four species have linear decurrent phyllodes and a similar habit. However, none of the other three species has spirally twisted or hooked phyllodes like those of D. implexa . Daviesia longifolia and D. pauciflora also differ from D. implexa in having one or more prominent longitudinal nerves between the midrib and margin; sometimes phyllodes of these species may be <2 mm broad, in which case they are terete or oblong in transection. Even the narrowest phyllodes of D. implexa are horizontally compressed.

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.