Daviesia scabrella Crisp, 2017

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

77. Daviesia scabrella Crisp , sp. nov.

Closely related to D. articulata , with which it shares needle-like phyllodes, a minutely scabrid epidermis and a distinctive starburst central mark on the standard, but differing in having a gracile, vegetatively spreading habit and lacking an articulation at the base of the phyllode. Daviesia devito and D. schwarzenegger are similar but their epidermis is smooth and the central mark on the standard differs.

Type [approximate locality data given because the species is rare]: WESTERN AUSTRALIA: Eyre District, near Condingup , ca. 33°30’S, 122°50’E, M. D. Crisp 11358, 15 October 2012. Holotype: CANB 812655 ; isotype: PERTH.

Dense, intricate, procumbent, spreading shrubs to 0.5 m high and several m across, probably rooting at nodes, minutely scabrous on vegetative parts, dull green. Root anatomy unclear, possibly developing anomalous secondary thickening. Branchlets numerous, divaricate, tangled, short, terete, obscurely striate when dry. Phyllodes evenly scattered, spreading, subulate, terete, straight or gently incurved, acicular and pungent at the apex, inarticulate and continuous with the branchlet at the base, 5–25 mm long, ca. 1 mm diam. at the base, slightly wrinkled upon drying, dull light green. Unit inflorescences racemose, 1 or 2 per axil, 1–3-flowered; peduncle 0.5–1 mm long; rachis 0–1.5 mm long; subtending bracts ascending, rhombic, trilobed, 0.25–0.6 mm long. Pedicels terete, 1–1.8 mm long. Calyx 2.8–3.6 mm long, tapered at base into the ca. 0.75 mm long, stipe-like receptacle, ± infused with purple-grey, lobes obscurely fimbriate at tips; upper 2 lobes united in a truncate, emarginate lip; lower 3 lobes triangular, acuminate, 0.6–1 mm long. Corolla : standard recurved, transversely broadly obovate, emarginate, ca. 5 × 5.5 mm including the 1 mm claw, outer portion pure yellow, centre intensely yellow surrounded by a red starburst-like border (fading); wings obovate, with rounded, strongly incurved and overlapping apices, auriculate, with a shallow sinus on the abaxial margin, ca. 4.5 × 2 mm including the 1.5 mm claw, yellow with variable red infusion centrally; keel strongly incurved, half transverse-broad-elliptic, acute, saccate, auriculate, ca. 3.4 × 1.2 mm including the 1.5 mm claw, dull red. Stamens strongly dimorphic: inner whorl of 5 with longer, slender, slightly compressed filaments and versatile, ovoid anthers with confluent thecae; outer whorl of 5 with strongly compressed filaments and basifixed, obloid, 2-celled anthers; filaments free. Pod obliquely broadly obtriangular, acuminate, compressed, 6–7 × 4–4.5 mm, semi-glossy, pale brown; upper suture sigmoid, lower suture curved through 80–120°. Seed not seen. ( Fig. 78 ).

Etymology:— The specific epithet, from Latin and meaning covered with minute hard points, refers to the texture of the epidermis.

Flowering period:— October. Fruiting period: unknown.

Distribution:— Western Australia, known only from the type locality and its vicinity ca. 100 km east of Esperance.

Habitat:— On an undulating plain in thin white sand over yellow-brown cracking clay, with calcrete nodules. In mallee-heath dominated by various eucalypts above several species of Melaleuca , Nematolepis phebalioides Turczinanow (1852: 158) and Daviesia lancifolia .

Conservation status:— Unknown. Although this species is known only from the type population, it occurs in a remote area at the edge of extensive tracts of uncleared land that has not been well-explored botanically.

A MONOGRAPH OF DAVIESIA

Phytotaxa 300 (1) © 2017 Magnolia Press • 177

Additional specimen examined:— [ Approximate locality data given because the species is rare]. WESTERN AUSTRALIA. Eyre: near Condingup , 33°30’S, 122°40’E, C . D. Turley & R. M . Hoggart BS 21/10-2008, 3 October 2008 ( PERTH) .

178 • Phytotaxa 300 (1) © 2017 Magnolia Press

CRISP ET AL.

Affinity:— This is one of the many species in the genus with needle-like phyllodes. Despite a strong superficial resemblance to D. devito this species is more closely related to D. articulata and D. campephylla (clade VII.b, Fig. 1B ), with which it shares a scaberulous (to hispidulous in the latter) epidermis and very similar floral morphology including a distinctive starburst-like central marking on the standard ( Fig. 78B ). The new species is easily distinguished from both D. articulata and D. campephylla by its inarticulate phyllode insertion, and also by its procumbent, widely spreading and more gracile growth habit. In general habit, and also in lacking an articulation at the phyllode base, D. scabrella resembles D. devito and D. schwarzenegger , but both the latter are restricted to eastern Australia and have a more robust growth habit, especially D. schwarzenegger . More specifically, both the latter have a smooth epidermis, in contrast to the minutely scabrid epidermis of D. scabrella . Also, D. devito differs in having small, black, triangular stipules—there are none in D. scabrella —and the mark on the standard of D. devito is broad, dark red and circular with a narrow, vertical yellow line at the centre, as in its sister species, D. genistifolia (q.v.).

Daviesia rhizomata resembles D. scabrella in growth-habit, with needle-like inarticulate phyllodes and a low spreading rhizomatous growth habit but the plant is glaucescent to bluish and the floral morphology differs, e.g. the standard has incurved margins and the central yellow mark is vertical and linear, not starburst-shaped. Daviesia benthamii and D. genistifolia differ from D. scabrella in having a non-scaberulous epidermis and additionally D. genistifolia has articulate phyllode bases. Although the molecular data indicate that D. scabrella is closely related to D. aphylla , the latter has a smooth epidermis, erect growth habit and phyllodes that are shorter (mostly ≤ 15 mm long), thicker (1–1.5 mm diam.) and only developed towards the branchlet apex, if at all.

VII.c. D.genistifolia Clade

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 78. Daviesia scabrella. Holotype. Photograph provided by the Curator of CANB.