Daviesia subulata Crisp & G.Chandler, 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

70. Daviesia subulata Crisp & G.Chandler , sp. nov.

Rigid shrub with phyllodes that are divaricate, decurrent, vertically compressed, subulate and pungent. In these respects it resembles D. decipiens , D. dilatata , D. decurrens , D. pectinata and D. intricata subsp. xiphophylla . It can be distinguished from all these species by the combination of: phyllodes straight (not recurved), diverging from the branchlet at 90° and not exceeding 12 mm in length; the sharply trigonous cross-section of the branchlets; the upper 2 calyx lobes not forming a truncate lip; pod compressed, not turgid.

Type : Western Australia , Irwin , ca. 38 km NNW of Morawa, 28°53’S, 115°51’E, T. R. Lally 1091 & B. J. Lepschi, 27 July 1996. Holotype: CANB; isotypes: AD, BRI, K, L, MEL, MO, NSW, PERTH, US.

Dense shrubs, 1–1.6 m high, 1.5–2 m wide, glabrous, pruinose. Root anatomy apparently unistelar but only a young root (<1 cm diam.) examined. Branchlets ascending, trigonous in cross-section, longitudinally striate or wrinkled when dry. Phyllodes rather crowded, divaricate, very rigid, vertically compressed, subulate, straight, apically acuminate and pungent, basally inarticulate and decurrent, 4–12 long, 1.5–4 mm broad, longitudinally striate with multiple nerves when dry and with a more prominent nerve near upper margin. Unit inflorescences 1 or 2 per axil, condensed-racemose, 2–5-flowered; peduncle 0.5–2 mm long; rachis 1–2.5 mm long; barren basal bracts oblong, keeled, <0.5 mm long; subtending bracts spreading, spathulate, hooded, keeled, fimbriate at apex, 0.5–1 mm long. Pedicels 1–1.5 mm long. Calyx 3–3.5 mm long including the 1–1.25 mm receptacle; upper 2 lobes united higher than the lower 3, broadly triangular, ca. 0.5–0.75 mm long; lower 3 lobes recurved, triangular, acuminate, ca. 0.5–0.75 mm long. Corolla : standard transversely elliptic, emarginate, base tapering into claw, ca. 5 × 6–6.5 mm including the 1–1.25 mm claw, standard yellow grading to red towards the centre; wings oblong to elliptic with a rounded and incurved apex, enclosing the keel, slightly auriculate, ca. 5–5.5 × 2 mm including the 1.5 mm claw; keel half transversely elliptic, scarcely acute, slightly auriculate, saccate, 4.5–5 × 1.75–2 mm including the ca. 1.5 mm claw, red, slightly paler towards apex. Stamens strongly dimorphic: inner whorl of 5 with longer, terete filaments and shorter, round, versatile anthers with confluent thecae; outer whorl of 5 with broader, shorter, compressed filaments and longer, oblong, basifixed, 2-celled anthers; filaments free. Pod obliquely shallowly obtriangular, acuminate, compressed, ca. 5 × 7 mm, purplish or lead grey at first; upper suture sigmoid; lower suture scarcely acute. Immature seed ellipsoid to obovoid with a prominent radicular lobe, longitudinally compressed, 2.5–3 mm long, ca. 2 mm long, brown with black speckling; aril rugose, very small (ca. 0.5 mm), often detaching with the funicle. ( Fig. 70 ).

Etymology:— Daviesia subulata is named after the shape of its phyllodes, which are subulate.

Flowering period:— July. Fruiting period: One specimen seen in early fruit, in October.

Distribution:— Restricted to several sites near Morawa, Western Australia.

Habitat:— Grows in gravelly, red-brown clay-loam on mostly disturbed sites including roadsides and an old quarry, in open scrub with Allocasuarina , Acacia , Hakea and scattered mallee eucalypts.

Conservation status:— Although this species is restricted to six known sites within a small area, only one of which is in a reserve, it is not currently considered threatened.

Additional specimens examined:— WESTERN AUSTRALIA. Irwin: 42 km N of Morawa towards Mullewa, track going E to roadside quarry, 28°54’S, 115°49’E, G . T . Chandler 648 & S . Donaldson, 24 October 1998 ( CANB, PERTH); 39.8 km from Morawa , N along rd to Mullewa, old gravel pit on E side of road in nature reserve, 28°54’S, 115°50’E, M . D. Crisp 9381 & L . G . Cook, 16 October 2001 ( CBG); 1.8 km NE of Canna Siding on Canna North East Road, ca. 38 km NNW of Morawa , 28°53’S, 115°51’E, T . R . Lally 1092 & B . J . Lepschi, 27 July 1996 ( AD, BRI, CANB, PERTH); as previous but 2.4 km NE of Canna Siding , 28°53’S, 115°51’E, T . R . Lally 1033 & B . J . Lepschi, 29 June 1996 ( CANB, MEL); near Site 8, Reserve 16491, located on Canna North East road, 28°53’S, 115°51’E, Morawa Tree Society 2038, 3 September 1994 ( PERTH) .

A MONOGRAPH OF DAVIESIA

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Affinity:— Daviesia subulata is most similar to D. dilatata and also resembles D. decurrens , D. pectinata and

D. intricata subsp. xiphophylla . Daviesia dilatata differs in having generally recurved-falcate, dilated phyllodes

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CRISP ET AL.

that are larger (7–50 mm long and 2–8 mm broad) than in D. subulata . Also, the upper 2 calyx lobes are united in a truncate lip and the lower 3 lobes are not recurved. The pod of D. dilatata is longer (7–8 mm) than that of D. subulata , but narrower (4–4.5 mm broad), and the lower suture is obtuse, giving the pod quite a different appearance.

Daviesia decurrens differs from D. subulata in having phyllodes that are falcate or recurved, at least at the tips. The subtending bracts of D. decurrens are much larger (to 2.5 mm long). The calyx lobes of D. decurrens are not flared outward, and D. decurrens has 5 prominent ribs. Daviesia decurrens has 2 prominent calli at the base of the standard-lamina and the stamens are weakly dimorphic, with the all anthers basifixed and 2-celled.

Daviesia pectinata is superficially similar but differs in having phyllodes that are generally much larger (8–70 × 2–9 mm). The upper 2 calyx lobes are united into a truncate lip, and there are more flowers per inflorescence (3– 10) than in D. subulata . Daviesia pectinata also has a more developed raceme-rachis (2–10 mm long) than does D. subulata .

D. intricata subsp. xiphophylla differs in having terete branchlets just below the phyllode base, lacking the prominent decurrent rib of D. subulata , and the phyllodes are reduced to scales for much of the branchlet length.

Figures

FIGURE 70. Daviesia subulata. Holotype. Photograph provided by the Curator of CANB.