Daviesia tortuosa Crisp (1995: 1239)

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

105. Daviesia tortuosa Crisp (1995: 1239) . Type: Western Australia, Roe [approximate locality data given because the species is rare]: near Lake Grace , 33°10’S, 118°20’E, M. D. Crisp 5539, 28 January 1979. Holotype: CBG; isotypes: K, L, MEL, MO, NSW, PERTH

Spreading, divaricate, intricate, wiry shrubs, to 1 m high and 2 m broad, glabrous, glaucous. Root anatomy with anomalous secondary thickening (cord type). Branchlets numerous, strongly zigzag and bending at the regularly spaced nodes, angular with prominent ridges. Phyllodes scattered, divaricate but curving inward so that the apex is antrorse, narrowly elliptic or narrowly obovate, margins longitudinally recurved to partly conceal the abaxial surface, apex acuminate, pungent, contracted to a petiole-like articulate base, 10–35 mm long, 4–12 mm broad (when flattened), with midrib obscure or absent, coriaceous, smooth when fresh, wrinkled when dry. Unit inflorescences often> 1 per axil, racemose, 2–5-flowered; peduncle 3–4 mm long; rachis flexuose, 2.5–9 mm long. Pedicels 1–2.5 mm long. Floral parts thick, fleshy. Calyx 4.5–5 mm long including the 1–1.5 mm receptacle; upper 2 lobes united in a truncate emarginate lip, ca. 1.5 mm long; lower 3 lobes triangular, ca. 0.75 mm long. Corolla : standard transversely broadly elliptic, 6.5–7 × 6.5–7 mm including the ca. 1.5 mm claw, with 2 calli at the base of the lamina, rich yellow with faint orange markings; wings spathulate, rounded and incurved and overlapping at apex to enclose the keel, auriculate, saccate, 6–7 × 3–3.5 mm including the ca. 2 mm claw, rich yellow; keel half transversely elliptic, acute, abaxially rugose, auriculate, saccate, ca. 5 × 2 mm including the 1.5 mm claw, rich yellow. Stamens weakly dimorphic: inner whorl of 5 with longer filaments and shorter, versatile anthers; outer whorl of 5 with shorter filaments and slightly longer, basifixed anthers; filaments compressed, free; anthers 2- celled. Pod obliquely shallowly obtriangular, tapered to a long, acute, pungent apex, turgid towards base, thick-walled, 18–20 × 8.5–9 mm; upper suture almost straight; lower suture scarcely acute. Seed globose, very plump, ca. 4 mm long, 3 mm broad, 2.5 mm thick, orange-brown; aril discontinuous at hilum, ca. 2.2 mm long. ( Fig.106 ).

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

Distribution:— Western Australia, central-eastern wheatbelt, approximately bounded by Kulin, Dumbleyung and Lake Grace.

Habitat:— Grows in kwongan heathland on gravelly lateritic or sandy soils.

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

Additional specimens examined:— Approximate locality data are given because the species is rare. WESTERN AUSTRALIA. Roe: Near Dudinin, 32°50’S, 117°50’E, R . D. Royce 5836, 7 April 1959 ( CANB, PERTH); W of Lake Grace , 33°10’S, 118°10’E, K . Ward 6711/68, April 1968 ( MEL, NSW, PERTH); ibid., K . Newbey 1499, 27 September 1964 ( PERTH); NE of Nyabing , 33°20’S, 118°20’E, J. M . Koch N36 , 19 January 1978 ( PERTH); near Lake Grace, Department of Agriculture , 33°10’S, 118°30’E, J . Nelson s.n., March 1968 ( PERTH 5201500 ); near Kukerin, 33°10’S, 118°10’E, A . Dunham s.n., 1 October 1962 ( PERTH 5147611 ) .

A MONOGRAPH OF DAVIESIA

Phytotaxa 300 (1) © 2017 Magnolia Press • 235 236 • Phytotaxa 300 (1) © 2017 Magnolia Press

CRISP ET AL.

Affinity:— In a genus of odd plants, this species stands out as bizarre. The combination of zigzag branchlets with thick, oddly shaped phyllodes can be confused with no other species. However, molecular data indicate that it is close to D. daphnoides and D. emarginata ( Fig. 1B ). In the flowers and pods, there is similarity to D. daphnoides , but the latter species is easily distinguished by its non-fleshy floral parts, scarcely flexuose branchlets and flat, erect phyllodes.

Figures

FIGURE 1A. Phylogeny (part) of Daviesia estimated using maximum likelihood (PHYML) from concatenated sequences of ITS (nrDNA), and ndhF and trnL–trnF (cpDNA). The tree was rooted using the monotypic sister groups Viminaria and Erichsenia (not shown). The informal clade names are used for reference in the taxonomic treatment. Numbers on branches show non-bootstrap support. The tips are labelled with the taxon name and sample accession number.

FIGURE 106. Daviesia tortuosa. A. Flowering branchlet. B. Phyllode, abaxial view. C. Inflorescence. D. Pod. A–D from Crisp 5539 (type). Drawn by B-J. Osborne. Adapted from Crisp (1995) with permission from CSIRO Publishing.