Daviesia laxiflora (J.H.Willis) Crisp (1991a: 282)

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

Phytotaxa 300 (1) © 2017 Magnolia Press • 125 52. Daviesia laxiflora (J.H.Willis) Crisp (1991a: 282) , Jeanes (1996: 758), Crisp (1995: 1207). Daviesia corymbosa Smith (1805: 507) var. laxiflora Willis (1957: 191) , excluding Grampians region populations. Daviesia mimosoides R.Br. var. laxiflora (J.H. Willis) J.H. Willis (1967: 123) . Type: ‘Slopes of Mt. Matlock toward Woods Point, at about 4000 ft., J.H. Willis, 2 November 1940 ’. Holotype: MEL 77965; isotype: MEL 77966

[ Daviesia corymbosa Sm. var. arborea auct. non (W.Hill) Maiden: H.B.Will. in Ewart (1931: 621)]

Large shrubs or small trees up to 10 m tall, glabrous, ± glaucous. Root anatomy unknown. Branchlets ascending or somewhat arching, angular. Phyllodes scattered, spreading at ca. 45°, narrowly elliptic to almost linear, long-acute to acute at apex, flat or gently undulate, slightly crenate, tapered towards the articulate base and finally contracted to a pseudo-petiole 3–15 mm long, 40–160 × 6–30 mm; secondary venation pinnate, usually prominent; tertiary venation coarsely reticulate, less conspicuous. Juvenile phyllodes elliptic to narrowly so; intermediate phyllodes proportionally broader (to 60 mm), acuminate to obtuse or rounded at apex, with the pseudo-petiole clearly differentiated. Unit inflorescences 1–3(–5) per axil, racemose, lax, with many evenly spaced flowers; peduncle 7– 15 mm long; rachis (13–) 25–100 mm long; barren basal bracts widely spaced, not imbricate; subtending bracts appressed to pedicels, subulate to deltoid, 1–2 mm long. Flowers very fragrant. Pedicels (1–) 2–7 mm long. Calyx 4.5–5.5 mm long including the ca. 1.5 mm receptacle to which it is contracted; upper 2 lobes united into a truncate to rounded, scarcely emarginate lip, ca. 1.5 mm long; lower 3 lobes similar, shallowly to very shallowly triangular, often tinged purple at the slightly acuminate apices, ca. 0.5 mm long. Corolla : standard transversely elliptic to transversely broadly elliptic, sometimes slightly oblong, emarginate, truncate to slightly cordate at base, 8.5–10.5 × 9.5–11.5 mm including the 2–2.5 mm claw, pure yellow with a narrow brownish red marking surrounding an intensely yellow oblong to bilobed spot at the centre; wings obovate to almost spathulate, rounded and incurved at the apex, ± enclosing the keel, auriculate, 8–9 × 3–4.5 mm including the 2–2.5 mm claw, yellow with a brownish red infusion towards the base; keel half very broadly obovate to depressed-obovate, acute, auriculate, saccate, 5– 5.5 × 2–2.5 mm including the 1.8–2.1 mm claw. Stamens strongly dimorphic: inner whorl of 5 with longer, compressed-terete filaments and discoid, versatile, anthers with confluent thecae; outer whorl of 5 with shorter, broader, very compressed filaments and compressed-ovoid, basifixed, 2-celled anthers; filaments free. Pod obliquely shallowly obtriangular, acuminate to scarcely obtuse, strongly compressed, 7–10 × 5–7 mm, usually straw-coloured, lustrous, smooth, rarely dull brown; upper suture sigmoid; lower suture acute. Seed compressed ellipsoid, 2.4–3.3 mm long, 1.6–1.9 mm broad, 1.3–1.4 mm thick, light brown to chestnut with black mottling, sometimes nearly all black; aril oblong in outline with a fleshy distal lobe, 1.4–2.4 mm long. ( Fig. 52 ).

Flowering period:— October to January. Fruiting period: January to March.

Distribution:— Restricted to Victoria, where it occurs in the highlands east of Melbourne, from near Marysville east to Mt Delusion and south to near Wilsons Promontory. Records from western Victoria are probably misidentifications of D. laevis .

Habitat:— This species occupies a specialised habitat in moist montane forests at elevations of 900 to 1300 m, or occasionally lower, e.g. Crisp 7630–1 at 460 m and Beauglehole 75418A from below 500 m. It typically occurs as a dominant understorey shrub, together with Acacia obliquinervia Tindale (1968: 76) , in tall open forest of Alpine Ash ( Eucalyptus delegatensis ). There it can also be associated with E. dalrympleana , E. obliqua or E. sieberi . At the lower-elevation site at Seaton (Crisp 7630–1), it grows in forest dominated by E. cypellocarpa Johnson (1962: 114) , E. obliqua and E. sieberi and stringybarks. Like D. suaveolens , D. laxiflora flowers prolifically, and the abundant large shrubs make an impressive display in the forest, which is permeated by the fragrance of the flowers.

Selected specimens (61 examined):— VICTORIA. Eastern Highlands : 1 km W of Mt Delusion, at junction of roads, 37°19’S, 147°31’E, A. C . Beauglehole 37071, 26 February 1971 ( CANB, MEL); Mt Margaret Gap , 37°29’S, 145°48’E, E. J . Carroll s.n., 21 December 1965 ( AD 97026144 , CBG 18057 ); Lake Mountain , ca. 1 km from Kellys Paddock towards summit, 37°30’S, 145°53’E, G. W . Carr 6374–9, 6 December 1975 ( CBG); 62.5 km N of Licola , 37°38’S, 146°37’E, J . Carrick 3140, 20 January 1972 ( AD, CANB); Jamieson to Licola , 37°21’S, 146°18’E, M . D. Crisp 7621, 8 November 1984 ( CBG, MEL, MO, NSW); Walhalla , 37°57’S, 146°27’E, M . Tindale s.n., 21 January 1967 ( NSW 137129 ); Seaton , towards Walhalla, 37°55’S, 146°37’E, M . D. Crisp 7630–1, 8 November 1984 ( AD, CBG, K, MEL, NSW); Bennison Plains , 37°28’S, 146°44’E, M . D. Crisp 8333, 1 December 1989 ( CBG, MEL, NSW); Bennison Spur , 37°30’S, 146°42’E, M . D. Crisp 8335, 1 December 1989 ( AD, CBG, HO, MEL, MO, PERTH); Mt Dow, Nicholson area , 37°26’S, 147°39’E, J. R . Turner 12, 25 November 1984 ( CANB,

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CRISP ET AL.

MEL); 6.4 km SE of Wrens Flat , 37°26’S, 146°23’E , J.H. Willis s.n., 24 February 1949 ( MEL 77959–60 ). Gippsland: Wilsons Promontory, 38°58’S, 146°18’E , E. Lyndon per A. C. Beauglehole 75418 A, 11 November 1983 ( CANB, MEL) .

Affinity:— Daviesia laxiflora is similar to D. laevis , D. latifolia and D. corymbosa . Although D. laxiflora was originally described as a variety of D. corymbosa , the latter may be readily distinguished by its corymbose inflorescences. Both D. laevis and D. latifolia differ in having larger (2–4 mm long), stipitate, patent bracts, scarcely fragrant flowers, and in addition, D. laevis has entire phyllode margins and shorter racemes (rachis 20–30 mm long, rarely to 80 mm). There is a montane form of D. latifolia which occupies the same habitat at different localities (mostly to the east of the range of D. laxiflora ) and superficially resembles D. laxiflora , but it may be distinguished by the bracts and lack of floral fragrance as indicated above. This comparison is discussed in more detail above, under the montane form of D. latifolia . Although D. laxiflora has been placed as a variety of D. mimosoides , these taxa are not especially closely related. Daviesia mimosoides differs in having much shorter racemes (rachis to 15 mm long) and smaller flowers (standard to 8 mm broad), which are scarcely fragrant.

Hybrids:— Daviesia laxiflora × D. leptophylla .

Figures

FIGURE 52. Daviesia laxiflora. A. Phyllode with axillary inflorescence. B. Flower. C. Calyx opened out, upper lip at left. D. Standard. E. Wings. F. Keel. G. Same, opened out. A from Carr 6374; B–G Crisp 7621. Drawn by A.L. Prowse and D. Fortescue. Adapted from Crisp (1991a) with permission from CSIRO Publishing.