Daviesia divaricata Bentham (1837b: 31)

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

14. Daviesia divaricata Bentham (1837b: 31) , Bentham (1837a: 75), Bentham (1864: 88), Crisp (1987a: 250), Crisp (1995: 1188), Wheeler et al. (2002: 747). Type: ‘King Georges Sound (Huegel.)’ Holotype: W

Daviesia paniculata Bentham (1837b: 31) , Bentham (1837a: 75), Bentham (1864: 88). Type: ‘Swan-River. (Huegel.)’ Lectotype (Crisp 1995: 1188): Freemantle [sic], Huegel 88 (W); isolectotype: K.

Low and spreading to bushy and erect, glaucous shrubs, 0.3–3 m high, glabrous except inside calyces ( subsp. lanulosa ). Root anatomy anomalous (cord type) in both subspecies, sometimes developing late. Branchlets terete, prominently ribbed, divaricate to ascending, spinescent. Phyllodes all reduced to triangular scales ca. 1 mm long, articulated at branchlet, keeled. Unit inflorescences 1 per axil, racemose or umbellate, 1–6-flowered; peduncle 1–3 mm long; rachis from almost nil to 3 mm long; subtending bracts oblong, appressed, ca. 1 mm long. Pedicels 2– 4.5 mm long. Calyx 4–4.5 mm long including the 1.5–2 mm receptacle, with or without a ring of hairs around the lobes (very thick and woolly in subsp. lanulosa ), with 5 ribs (prominent in subsp. lanulosa ); upper 2 lobes united into a broad, truncate lip ca. 0.25 mm long ( subsp. divaricata ), or united higher than the lower 3 and ca. 0.75 mm long ( subsp. lanulosa ); lower 3 lobes broadly triangular, ca. 0.25–0.75 mm long. Corolla : standard strongly reflexed, depressed-ovate, deeply emarginate, 6.5–8.5 × 8–10 mm including the 1–1.5 mm claw, with 2 raised calli at the base of the lamina, deep orange on the outer half, with a deep maroon inner half that has 2 yellow linear marks at 45° (forming a ‘V’); wings obovate with a rounded, incurved apex, strongly auriculate, saccate, 5–7 × 2– 2.5 mm including the 1.5–2 mm claw, deep maroon; keel half very broadly obovate with an acute apex, saccate, 5– 6 × 1.5–2 mm including the ca. 1.5 mm claw, deep maroon. Stamens strongly dimorphic: inner whorl of 5 with longer, slender filaments and shorter, rounder, versatile anthers with confluent thecae; outer whorl of 5 with shorter, broader, compressed filaments and longer, oblong, basifixed, 2-celled anthers; filaments free. Pods obliquely shallowly obtriangular, acute to acuminate, 11–16 × 5–8 mm; upper suture sigmoid; lower suture acute but broadly rounded. Seed oblong, sometimes compressed horizontally, 4.2–4.6 mm long, 2.5–3 mm broad, 1.4–2 mm thick, light brown with some black mottling; aril 2.5–3 mm long, extending over the end of the seed. ( Fig. 16 ).

Flowering period:— May to early November. Fruiting period: August to November.

Distribution:— Western Australia, sandplains and dunes, mainly near the coast, from the Hutt River Plains south to the Busselton area.

50 • Phytotaxa 300 (1) © 2017 Magnolia Press

CRISP ET AL.

Affinity:— Daviesia divaricata is closely related to D. localis , with which it shares a distinctive pair of divergent yellow markings at the base of the standard, often basally joined to form a ‘V’ shape, as well as generally similar morphology in the growth habit, including spined-tipped striate to ribbed branchlets, and similarity of the reproductive parts. Molecular data also strongly support a sister group relationship between these two species ( Fig. 1A ). Daviesia localis is readily distinguished by the presence of terete, pungent phyllodes 2–8 mm long, and by the viscid inflorescences. Daviesia divaricata may be confused with leafless specimens of D. horrida , which differs in having an orange (not yellow) standard with a single (not two) vertical yellow mark in the dark red centre and spreading, truncate (not appressed, acute) bracts.

A MONOGRAPH OF DAVIESIA

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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 16. Daviesia divaricata subsp. divaricata. A. Branchlet in bud, flower and immature fruit. Daviesia divaricata subsp. lanulosa. B. Inflorescence with flowers represented by calyces only (woolly hairs are internal and not visible from this angle). C. Pod. A from M.E. Phillips WA/62-924; B, C from Crisp 6312. Drawn by B-J. Osborne.