Daviesia chapmanii Crisp (1995: 1181)

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

127. Daviesia chapmanii Crisp (1995: 1181) . Type: Western Australia, Irwin, 16 km N of Hill River bridge along Brand Hwy , 30°15’S, 115°26’E, M. D. Crisp 6213, J. Taylor & R. Jackson, 29 September 1979. Holotype: CBG; isotypes: NSW, PERTH

Dense, rounded shrubs, to 0.8 m high and 1.5 m broad, glabrous, dull dark green. Root anatomy unknown. Branchlets spreading to ascending, terete, striate in vivo with multiple sharp longitudinal ridges. Phyllodes very crowded, their broad bases overlapping along branchlets, diverging at 60–110°, vertically compressed, oblong to triangular, usually narrow, often slightly oblique or recurved, slightly thickened along margins, apically acuminate, pungent, articulate at the base, (7.5–)10–15(–20) × 2.5–4 mm, striate (prominently when dry), dull green. Unit inflorescences 1(2) per axil, racemose, 1–4-flowered; peduncle 0.5–1.5(–14) mm long, very thick when> 2 mm long; rachis 0.25–1(–2) mm long; barren basal bracts narrowly oblong, ca. 0.5 mm long, numerous, overlapping at

A MONOGRAPH OF DAVIESIA

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the base of the peduncle except when the peduncle is> 2 mm long, where they are scattered; subtending bracts oblong, hooded, slightly keeled, ca. 1 mm long. Pedicels gently dilated upwards, 3–5.5 (8) mm long. Calyx 3–3.5 mm long including the 1.25–1.5 mm receptacle (sometimes markedly stipe-like); lobes subulate; upper 2 lobes united into a narrow, truncate lip, <0.5 mm long; lower 3 lobes triangular, ca. 0.75 mm long. Corolla pale yellow to almost white with deep pink markings; standard broadly obovate to broadly elliptic with a rounded apex, contracted at base, 8–8.5 × 6–9 mm including the 0.5–1 mm claw, 2 large calli present at the base of the lamina, pale yellow with a red centre; wings narrowly obovate with a rounded apex, sometimes slightly oblique, with hooked auricles, 7–8 × 2–2.5 mm including the 1–1.5 mm claw, red; keel half broadly ovate, acuminate with an acicular beak, auriculate, ca. 7–8 × 1.75–2 mm including the ca. 3 mm claw, yellow. Stamens slightly dimorphic: inner whorl of 5 with longer, ca. terete filaments and shorter, versatile anthers; outer whorl of 5 with shorter, broader, compressed filaments and longer, basifixed anthers; filaments cohering towards base; anthers all 2-celled. Pod obliquely very broadly to shallowly obtriangular with an acute apex, turgid, 12–14 × 9–10 mm; upper suture almost straight to slightly sigmoid; lower suture acute but broadly rounded. Seed globose to obloid, ca. 3 mm long, 2 mm broad, 1.6 mm thick, brown to black; aril ca. 1 mm long. ( Fig. 128 ).

Flowering period:— Mostly April and May, occasionally in August. Fruiting period: Mostly September and October, occasionally in August.

Distribution:— Western Australia, a restricted distribution from Eneabba south to Badgingarra and inland to near Carnamah.

Habitat:— Grows in sand, sandy gravel or gravelly clay over laterite on undulating terrain in kwongan heathland.

Selected specimens (14 examined):— WESTERN AUSTRALIA. Irwin: Winchester West, 29°46’S, 115°56’E, C . Chapman s.n., 18 April 1969 ( CBG 484000 , PERTH); 1 mile [1.5 km] E of Brand Highway on Coorow Green Head Road , 30°05’S, 115°23’E, C . Chapman (6 B)77, 15 May 1977 ( PERTH); 42 km W of Winchester , 29°47’S, 115°35’E, C . Chapman (83)77, 18 September 1977 ( CBG, PERTH); Mt Peron , 30°07’S, 115°09’E, C. A . Gardner 9420, 26 August 1949 ( PERTH); junction of Brand Highway and Jurien Bay Road, 30°11’S, 115°23’E, R . Hnatiuk 770002, 26 April 1977 ( PERTH); Cadda Road , 5.9 km E of junction with Munbinea Road, 30°23’S, 115°17’E, S . Patrick 1318, 20 October 1992 ( CANB, PERTH) .

Affinity:— This species belongs to a large natural group within the genus exemplified by D. incrassata , with which it shares turgid pods, a distinctive calyx that is flared from just below the teeth, an incurved beaked keel, weakly dimorphic stamens and cord roots. Within the D. incrassata group, it belongs to a smaller group having striate phyllodes (when dry) with thickened margins and narrow, usually sharp ridges along the branchlets (including D. angulata , D. mesophylla , D. microphylla , D. polyphylla , D. preissii and D. spinosissima ). However, only this species, D. microphylla , D. spinosissima and D. striata have very crowded phyllodes whose broad bases overlap along the branchlets. Daviesia microphylla differs in having spinescent branchlets and phyllodes ≤ 5 mm long. Daviesia spinosissima differs in having subulate phyllodes that are thickened at the basal articulation. Superficially, D. striata is most similar to D. chapmanii : the phyllodes are similar in shape, and they overlap along the branchlets; however, the D. striata plant is glaucous to pruinose and the branchlets are longitudinally wrinkled (when dry), whereas in D. chapmanii they have multiple sharp ridges, even in vivo.

Figures

FIGURE 128. Daviesia chapmanii. A. Flowering branchlet. B. Inflorescence (1-flowered) with floral parts except calyx removed. C. Pod. A, B from C. Chapman (6B)77, C from C. Chapman (83(77). Drawn by B-J. Osborne. Adapted from Crisp (1995) with permission from CSIRO Publishing.