Daviesia pleurophylla Crisp (1995: 1221)

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

13. Daviesia pleurophylla Crisp (1995: 1221) . Type [approximate locality data given because the species is rare]: Western Australia, Cape Range, 22°20’S, 113°50’E, A.S. George 10288, 5 September 1970. Holotype: PERTH; isotypes: CBG, K, MEL

Large open shrubs to 3 m tall, often single- or few-stemmed at base, with an open divaricately branched crown, glabrous. Root anatomy normal (unistelar). Branchlets numerous, gently flexuose, terete, striate with multiple pale ribs, subspinescent; nodes pale yellowish. Phyllodes scattered, widely spreading, needle-like, acuminate, pungent, articulated at base, 5–25 mm long, ca. 0.75 mm diam., striate with multiple pale ribs. Unit inflorescences 1(2) per axil, racemose to umbellate, 2–4-flowered; peduncle 3–18 mm long; rachis from almost nil to 6 mm long; subtending bracts ascending, narrowly oblong, ca. 1 mm long. Pedicels 2–4 mm long. Calyx campanulate, 3–4 mm long including the ca. 1.5 mm, stipe-like receptacle which is nearly as long as the tube, with 10 ribs extending from teeth and sinuses to the pedicel; lobes uniform with teeth acuminate or reduced, ca. 0.5–0.75 mm long. Corolla yellow and dark red; standard transversely elliptic, emarginate, ca. 5.5 × 6 mm including the ca. 1.5 mm claw; wings

48 • Phytotaxa 300 (1) © 2017 Magnolia Press

CRISP ET AL.

A MONOGRAPH OF DAVIESIA

Phytotaxa 300 (1) © 2017 Magnolia Press • 49 obovate, rounded and strongly incurved at apex, auriculate, with a lobe opposite on the abaxial margin, ca. 5 × 2.25 mm including the ca. 1.5 mm claw; keel half broadly elliptic, obtuse, saccate, ca. 4 × 1.5 mm including the 1 mm claw. Stamens strongly dimorphic: inner whorl of 5 with longer, slender filaments and shorter, round, versatile anthers with confluent thecae; outer whorl of 5 with shorter, broader, strongly flattened filaments and longer, slender, basifixed, 2-celled anthers; filaments free. Pods obliquely shallowly obtriangular, acute, compressed, ca. 13–14 × 8 mm long, straw-coloured; upper suture sigmoid; lower suture acute but broadly rounded. Seed ellipsoid, compressed, ca. 4.7 mm long, ca. 3 mm broad, ca. 0.8 mm thick; aril 0.8 mm long. ( Fig. 15 ).

Flowering period:— One specimen flowering in September. Fruiting period: one specimen seen fruiting in September.

Distribution:— Known only from the Cape Range–Exmouth area, Western Australia.

Habitat:— Grows in open tall shrubland on deep red sand dunes, where it is locally dominant.

Conservation status:— National: Not listed. WA: Priority 2, possibly threatened or near-threatened but not yet adequately surveyed.

Additional specimen examined:— Approximate locality data given because the species is rare. WESTERN AUSTRALIA. Carnarvon: Near Exmouth , 21°50’S, 114°10’E, M . D. Crisp 9380 & L. G . Cook, 12 October 2001 ( CANB, PERTH) .

Affinity:— This is one of the few species in the genus that are restricted to the tropics; moreover, it is a distinctive plant that cannot be confused readily with any other. It shares some features with the closely related D. costata , D. longifolia and D. pauciflora . For example, the inflorescence and ribbing on the branchlets are similar to those in all three species, and ribbed phyllodes are seen in D. longifolia and D. pauciflora . Additionally, D. costata has uniform calyx-teeth and very similar petals to those of D. pleurophylla , notably the standard, which is broader than long (a rare feature in the genus). However, D. costata immediately differs from D. pleurophylla in its flat, linear, longer phyllodes and the lack of an articulation at their base.

Figures

FIGURE 15. Daviesia pleurophylla. A. Flowering branchlet. B. Inflorescence in bud. C. Pod. A–C from George 10288 (isotype). Drawn by B-J. Osborne. Adapted from Crisp (1995) with permission from CSIRO Publishing.