Daviesia spiralis Crisp (1982a: 9)

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

33. Daviesia spiralis Crisp (1982a: 9) , Crisp (1995: 1238). Type [approximate locality data given because the species is rare]: Wongan Hills area , 30°50’S, 116°40’E, 26 January 1979, M. D. Crisp 5491, fl., fr., spirit material, photos. Holotype: CBG; isotypes: CANB, K, NSW, PERTH, US

Intricate, rounded shrubs to 1.5 m tall and broad, muriculate on branchlets and phyllodes. Root anatomy normal (unistelar). Branchlets ascending to erect, terete, ribbed. Phyllodes scattered, ascending or spreading, linear, twisted in a right-handed spiral, apically attenuate and uncinate, basally inarticulate and decurrent, to 100 × 3 mm, much reduced towards branchlet apex; with a central and 2 marginal ribs but no visible veins; stipules minute, ≤ 0.5 mm long. Unit inflorescences 1–few per axil, flowers solitary or an umbel of 2; peduncle 2–8 mm long; subtending bracts oblong to obovate, keeled, spreading at the tips, 1–1.5 mm long, some tips fimbriate. Pedicels 5–18 mm long, viscid, narrowly clavate with an apical flange. Calyx campanulate, 4–4.5 mm long; upper 2 lobes united in a truncate emarginate lip; lower 3 lobes triangular, 1.5 mm long. Corolla : standard transversely broadly elliptic, emarginate, slightly cordate, 6.5–7.5 × 8–10 mm including the ca. 1 mm claw, with 2 calli at the base of the lamina, yellow, with a rich yellow central oblong or bilobed marking, bordered with a dark red infusion; wings irregularly obovate, shortly beaked, auriculate, saccate (to shallowly so), 7–7.5 × 3–3.5 including the ca. 1.5 mm claw, reddish; keel subulate, inflexed, supervolute in the upper half, very acutely beaked, slightly auriculate, deeply saccate, 7.5–9 × 2–3 mm including the ca. 1.5 mm claw, reddish grading to maroon at the apex. Stamens weakly dimorphic; inner whorl of 5 with longer, terete, slightly narrower filaments; outer whorl of 5 with shorter, broader, compressed filaments; filaments free; anthers all basifixed, ovoid, 2-celled, sometimes beaked at the apex. Ovary subsessile, narrowly oblong; style inflexed. Pod obliquely shallowly obtriangular, long-acute, compressed, 10–13 × 4.5–5 mm. Seed compressed, ovoid-elliptic, 3–4 mm long, 2–2.5 mm wide, 1.7–2 mm thick, pale brown speckled with black; aril conspicuous, ca. 1.5 mm long. ( Fig. 34 ).

A MONOGRAPH OF DAVIESIA

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

Distribution:— Western Australia, north-central wheatbelt, endemic to the Wongan Hills area.

Habitat:— Daviesia spiralis appears to grow exclusively in laterite-derived clay and gravel. It is associated with mallee-shrubland dominated by various eucalypts and Allocasuarina campestris ( Diels 1904: 126) Johnson (1982: 74) , with Banksia species common. However, like many species of Daviesia , it tends to be most numerous in disturbed sites. At the type locality, it is associated with the type population of D. debilior subsp. sinuans .

Conservation status:— National: Not listed. WA: Priority 4, adequately known and near-threatened or not threatened, requiring regular monitoring.

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CRISP ET AL.

Selected specimens (8 examined):— Approximate locality data given because the species is rare. WESTERN AUSTRALIA. Avon: Wongan Hills area , 30°50’S, 116°40’E, B. H . Smith 268, 29 August 1983 ( CBG, MEL, PERTH); ibid., K. F . Kenneally 2303, 21 September 1974 ( PERTH); ibid., K. F . Kenneally 7155, 12 December 1979 ( PERTH, CANB); ibid., M . D. Crisp 9024 & W . Keys, 26 October 1996 ( AD, CBG, K, PERTH) .

Affinity:— This species has distinctive spirally twisted phyllodes, which makes it difficult to confuse with any other species of Daviesia , except perhaps D. implexa . However, in D. implexa the phyllodes are loosely twisted through 1–3 turns, whereas the phyllodes of D. spiralis form a corkscrew shape, with many turns. Additionally, the phyllodes of D. implexa are pruinose and smooth, the pedicels are neither viscid nor flanged at the apex, the standard lacks calli, and the bracts are appresssed, subulate and not fimbriate.

Figures

FIGURE 34. Daviesia spiralis. A. Flowering branchlet. B. Inflorescence. C. Standard, adaxial view. D. Same, showing calli in transection (indicated by arrows in C), adaxial face upward. E. Wing. F. Keel. G. Pod. H, I. Seed in lateral and hilar view respectively. A from Kenneally 2303; B–I from Crisp 5491 (holotype). Drawn by B-J. Osborne and M.D. Crisp.