Daviesia glossosema Crisp (1995: 1194)

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

111. Daviesia glossosema Crisp (1995: 1194) . Type [approximate locality data given because the species is rare]: Western Australia, Eyre, Stirling Range , 34°20’S, 118°20’E, M. D. Crisp 6121, J. Taylor & R. Jackson, 25 September 1979. Holotype: CBG; isotypes: CANB, K, MEL, MO, NSW, PERTH

A MONOGRAPH OF DAVIESIA

Phytotaxa 300 (1) © 2017 Magnolia Press • 249 Intricate shrubs, 0.5–1(–1.5) m high, minutely scabrid, glaucous. Root anatomy unknown. Branchlets divaricate, arching, terete, striate when fresh, ribbed when dry. Phyllodes scattered, diverging at (45–)60–90°, terete, ± gently recurved from the base with an acuminate pungent apex, basally articulate, 8–40 × 0.75(–1) mm, scarcely rigid, faintly striate when fresh, ribbed when dry. Unit inflorescences 1 per axil, racemose, pendulous, umbelliform, 2–5- flowered; peduncle 4–7 mm long; rachis 1–3 mm long; barren basal bracts few, spreading to ascending, scattered along peduncle, ca. 0.5 mm long; subtending bracts spreading, oblong, ca. 1 mm long. Pedicels bent so that flowers face outwards, 3–5 mm long. Calyx obliquely cup-shaped, adaxially ventricose, ca. 4 mm long and broad, including the ca. 1.25 mm receptacle; teeth minute, uniform. Corolla maroon, paler with dark red spots in longitudinal lines towards the base; standard ovate, tongue-like, very strongly recurved, channelled, 10–10.5 × 5–6 mm including the 1.5–2 mm claw; wings with margins involute and apices strongly incurved and interlocked to form a U-shape (viewed from above), exposing the keel and stamens, 11.5–13.5 × 3 mm including the 2.5–3 mm claw; keel half very broadly obovate, much shorter than wings, scarcely acute, with claw longer than laminas, soon opening to display stamens and style, saccate, 8.5 × 1.75–2 mm including the 4.5–5 mm claw. Stamens weakly dimorphic, at anthesis splayed in the gap between standard and wings; inner whorl of 5 with narrower, terete filaments and slightly shorter, subversatile anthers; outer whorl of 5 with broader, compressed filaments and slightly longer, subbasifixed anthers; filaments free, ca. equal in length, all broader towards the base; anthers all 2- celled. Gynoecium almost straight. Pod obliquely shallowly to rarely very broadly obtriangular with an acuminate apex, very turgid, 14–20 × 10–12 mm; upper suture curved gently upwards; lower suture acute, ventricose and protruding beyond apex. Seed not seen. ( Fig. 112 ).

Flowering period:— September to November. Fruiting period: October to December.

Conservation status:— National: Critically Endangered. WA: Critically Endangered, Declared Rare Flora.

Distribution:— Endemic to the Stirling Range, Western Australia.

Habitat:— Grows on loamy sand with quartz pebbles on a gentle footslope of the range, in mallee-heath or closed-heath dominated by Eucalyptus marginata , E. staeri , Banksia spp. , Hakea pp., Lambertia , Taxandria , sedges and other Fabaceae .

Selected specimens (7 examined):— Approximate locality data are given because the species is rare. WESTERN AUSTRALIA. Eyre: Stirling Range , 34°20’S, 118°20’E, M . D. Crisp 5269, 18 January 1979 ( CBG); ibid., S . Barrett 881, 12 October 2000 ( PERTH); Stirling Range , 34°20’S, 118°10’E, S . Barrett 883, 11 October 2000 ( PERTH) .

Affinity:— This species has remarkable flowers that cannot be confused with those of any other species in the genus. The pendulous inflorescence, maroon petals and strange shapes of the floral parts, as well as the exposure of the stamens and style at anthesis, are unique and suggest a specialised adaptation to an unusual pollinator. The reddish flower colour is reminiscent of some bird-pollinated Gastrolobium species ( Crisp 1994, Toon et al. 2014) but the floral morphology is quite different. The small size of the flowers and the open brush arrangement of the stamens suggest an insect pollinator, possibly flies. Additionally, the very large, turgid pod is like that of no other species, except D. inflata , which is easily distinguished by its conventionally shaped, orange-red, bee-pollinated flowers. On the other hand, the vegetative form of D. glossosema is unremarkable compared with closely related species D. brachyphylla , D. incrassata and D. physodes ( Fig. 1B ). However, the minutely scabrous epidermis distinguishes it from all these.

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 112. Daviesia glossosema. A. Flowering branchlet. B. Inflorescence. C. Pod. A, B from Crisp 6221 (type); C from Crisp 5269. Drawn by A.L. Prowse. Adapted from Crisp (1995) with permission from CSIRO Publishing.