Daviesia articulata Crisp (1995: 1173)

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

76. Daviesia articulata Crisp (1995: 1173) . Type: Western Australia, Roe, ca. 30 km E of Ravensthorpe , 8 km WNW of trig ESA5 , 33°38’S, 120°22’E, M. D. Crisp 6058, J. Taylor & R. Jackson, 22 September 1979. Holotype: CBG; isotypes: AD, CANB, K, MEL, NSW, PERTH

Procumbent, spreading or erect, rigid shrubs, to 1 m tall and 2 m broad, minutely scabrous on vegetative parts, tending to hirsute in south-eastern plants. Root anatomy unknown. Branchlets numerous, divaricate, short, terete, obscurely striate when dry. Phyllodes evenly scattered, situated on thickened nodes, spreading, subulate, terete, straight or gently recurved, acuminate and pungent at the apex, articulate and abruptly thickened at the base, 3–40 × 0.75–1.25 mm, wrinkled upon drying, rigid and easily broken away, glossy, dark green. Unit inflorescences racemose, 1 per axil, 1–5-flowered; peduncle ca. 1 mm long; rachis 1–8 mm long; subtending bracts recurved, oblong or spathulate, obscurely trilobed, ca. 0.5 mm long. Pedicels narrowly clavate, 0.5–3 mm long. Calyx 2.5–4 mm long, tapered at base into the ca. 1 mm long, stipe-like receptacle, lobes shortly fimbriate; upper 2 lobes united in a truncate, emarginate lip; lower 3 lobes triangular, acuminate, ca. 1 mm long. Corolla : standard strongly recurved, very broadly ovate, emarginate, cordate, ca. 7 × 7.5 mm including the 2 mm claw, outer portion pure yellow, centre intensely yellow surrounded by a red starburst-like border (fading); wings obovate, with rounded, strongly incurved and overlapping apices, auriculate, ca. 6.5 × 2 mm including the 2 mm claw, red with yellow tips; keel half very broad-elliptic, scarcely acute, saccate, auriculate, ca. 5 × 1.5 mm including the 2 mm claw, dark red. Stamens strongly dimorphic: inner whorl of 5 with longer, slender, angular-terete filaments and versatile, ovoid anthers with confluent thecae; outer whorl of 5 with shorter, strongly compressed filaments and basifixed, obloid, 2-celled anthers; filaments free. Pod obliquely broadly obtriangular, acuminate, compressed, 8–11 × 4.5–6 mm, glossy, red-brown; upper suture sigmoid and lower suture sharply curved. Seed not seen. ( Fig. 77 ).

Flowering period:— August to December. Fruiting period: January.

Distribution:— Western Australia, scattered across the southern wheatbelt and mallee districts, in an area bounded approximately by Kellerberrin in the north, Kojonup in the west, the Stirling Range in the south, and Salmon Gums–Esperance in the east.

Habitat:— Grows in soils such as sand, sandy loam or most commonly clay, sandy clay or gravelly clay, on slopes or plains, under mallee eucalypts with a shrub understorey (e.g. broombush Melaleuca ), or in woodland dominated by eucalypts such as E. wandoo .

Selected specimens (17 examined):— WESTERN AUSTRALIA. Avon: 7 km from Nyabing along road to Katanning, 33°34’S, 118°04’E, M . D. Crisp 5201, 16 January 1979 ( CBG, PERTH). Coolgardie: Bremer Range , 32°31’S, 120°46’E, C. A . Gardner s.n., November 1929 ( PERTH 5481368 ). Roe: Near 105 mile peg, Borden – Pingrup road, A. M . Ashby 4666, 9 September 1972 ( PERTH); ca. 50 km WSW of Salmon Gums, 23 km NW of Roberts Swamp , 33°07’S, 121°09’E, K . Newbey 8195, 13 November 1980 ( PERTH); W of Salmon Gums, Frank Hann National Park, 32°45’S, 121°09’E, R . D. Royce 10216, 10 December 1971 ( PERTH, SYD); 11 km E of Ongerup , 33°47’S, 118°36’E, K . Newbey 1480, 26 September 1964 ( PERTH); 2.4 km S of cross-roads Forrestania, 32°25’S, 119°45’E, F . Lullfitz 3969, 8 December 1964 ( PERTH); near Scaddan , 33°27’S, 121°44’E, M . D. Crisp 9949 & L. G . Cook, 16 September 2005 ( CANB, PERTH); ca. 1.3 km SE of intersection of Rhinds Road and Dalyup Road , 33°20’S, 121°35’E, E. M . Sandiford 120 ( PERTH). Eyre : SW of Eyre Range, 33°51’S, 119°59’E, A. S . George 7227, 1 November 1965 ( PERTH); Phillips flats and near East Mt Barren , G . Maxwell s.n., sine die ( MEL 72501 ) .

Affinity:— Daviesia articulata is perhaps most similar to D. genistifolia , which it resembles in most respects, despite a geographic separation of> 1500 km. The smooth (not scaberulous) surface and dull, light grey-green colour of the phyllodes of D. genistifolia readily distinguish it from D. articulata . In addition, D. genistifolia has floral differences: the base of the standard is truncate or broadly fan-shaped, the wings are ≤ 5.5 mm long, only slightly incurved and scarcely overlapping at the apices, the standard has a large central semi-circle infused with dark red and the tips of the wings are red (red infusion fading grey with age).

Another taxon that may be confused with D. articulata is D. asperula subsp. asperula , which is not especially closely related, but also has scaberulous branchlets and phyllodes. Daviesia asperula differs from D. articulata in having dull, grey-green, striate phyllodes, a standard-petal with a broadly fan-shaped base and a pod with a less sharply curved lower suture. The floral markings of D. asperula are very similar to those of D. genistifolia and, in this respect, also differ from those of D. articulata .

A MONOGRAPH OF DAVIESIA

Phytotaxa 300 (1) © 2017 Magnolia Press • 175 176 • Phytotaxa 300 (1) © 2017 Magnolia Press

CRISP ET AL.

Many species of Daviesia , too numerous to mention here, have more or less terete, pungent, articulate phyllodes and could be confused with D. articulata . All are more distantly related to D. articulata than are D. genistifolia and D. asperula and can be distinguished by floral and fruiting characters. The two species with perhaps the strongest superficial resemblance to D. articulata are D. angulata and D. preissii , both being distinguished by their larger (13–20 mm long), turgid pods. In D. angulata , the branchlets differ from those of D. articulata in being angular with sharp ridges. The phyllodes of D. preissii differ from those of D. articulata in being striate, smooth (not scaberulous) and usually compressed or flattened in the vertical plane, and the pods are turgid and much larger. The molecular phylogeny shows D. articulata to be nested within D. aphylla (clade VII.b, Fig. 1B ) but the latter differs in having short (<20 mm) divaricate phyllodes that are restricted to the branchlet apex and are continuous (not articulate) with the branchlet.

Variation:— Plants in the eastern portion of the species’ range (e.g. Crisp 9949 and Sandiford 120) tend to be shortly hirsute, with gently recurved, short (2–15 mm long) phyllodes. Otherwise, they intergrade imperceptibly with typical populations and are not recognised here as a distinct taxon.

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 77. Daviesia articulata. A. Flowering branchlet. B. Inflorescence. C. Pod with persistent standard. A, B from Crisp 6058; C from Crisp 5201. Drawn by B-J. Osborne. Adapted from Crisp (1995) with permission from CSIRO Publishing.