Daviesia schwarzenegger Crisp & L.G.Cook, 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

73. Daviesia schwarzenegger Crisp & L.G.Cook , sp. nov.

This taxon was previously included in D. benthamii subsp. humilis , but here we divide this subspecies into two cryptic species ( D. devito and D. schwarzenegger ) first recognised from molecular data. Daviesia schwarzenegger is distinguished from

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CRISP ET AL.

its cryptic twin D. devito by lacking stipules, having wrinkled rather than ribbed branchlets and phyllodes (when dry), and its overall more robust appearance.

Type [approximate locality data given because the species is rare]: New South Wales, W of West Wyalong , 33°50’S, 147°00’E, M. D. Crisp 11747, 7 September 2016. Holotype: CANB 893045 ; isotype: NSW.

[ D. benthamii Meisner (1844: 48) subsp. humilis Crisp (1982b: 60 , partly, not including the type), Crisp (1995: 1176, partly), Jeanes (1996: 761, partly), Crisp (2002: 524, partly), Craigie (2015: 29, partly).]

Dense, hummocky shrub to 1.3 m high and × 3 m broad, suckering from roots, glabrous, dull green to glaucescent. Root anatomy normal (unistelar). Branchlets rigid, ascending, terete and smooth when fresh, longitudinally wrinkled when dry. Phyllodes scattered, divaricate, terete to obscurely angular when dry, acicular and pungent at apex (spine 1–2 mm long), inarticulate and somewhat decurrent at the base, 10–25(–35) mm long, 1–2 mm diam. at base, not or scarcely increasing in length down the branchlet and replaced by scales only near the branchlet base, rigid and robust; stipules absent. Inflorescences racemose, usually condensed, 2–4-flowered; barren basal bracts forming an imbricate involucre; subtending bracts covering inflorescence rachis, but less than 1–2 mm long, keeled, minutely ciliate at the margins, mauve; rachis 1–5 mm long, angular. Pedicels ca. 1 mm long. Calyx campanulate, faintly ribbed, glabrous except at margins, often pruinose; lobes subequal with the lower 3 recurved and acuminate. Corolla : standard transversely elliptic, retuse, 3–4 × 4 mm including the ca. 1 mm claw, orange-yellow at margins, grading through red and maroon towards the central linear-oblong yellow stripe, fading with age to yellow and grey; wings obovate, rounded and incurved but not enclosing the keel, auriculate, 4.5–5 × 1.75–2.5 mm including the ca. 1.5 mm claw, dark red with orange tips; keel half transversely broadly elliptic, acute, auriculate, 4 × 1.5 mm including the 1.5 mm claw, very dark red. Stamens strongly dimorphic: inner whorl of 5 with longer, slender, terete filaments and shorter, round, versatile anthers with confluent thecae; outer whorl of 5 with shorter, broader, compressed filaments and longer, oblong, basifixed, 2-celled anthers; filaments free. Pod broadly obtriangular, slightly obtuse, strongly compressed, 5–7 × 4–6 mm, slightly rounded in outline; upper suture slightly sigmoid; lower suture acute but broadly rounded. Seed reniform, brown with black mottling, with a small rugose aril. ( Fig. 74A, B ).

Etymology:— Surprisingly, DNA sequence data showed D. benthamii subsp. humilis to comprise two cryptic species that are more closely related to other species than to D. benthamii (see details under Affinity below). As they are unexpected and unlikely ‘twins’, we have named them after the actors who played an unlikely pair of twins in the eponymous Hollywood movie: Arnold Schwarzenegger and Danny DeVito. We have named this species after Schwarzenegger because he is much more robust than his twin: ‘The embryo did split in two, but it didn't split equally. All the purity and strength went into Julius [Schwarzenegger’s character]’. This difference between the actors parallels the growth habit difference between the two Daviesia species. We also wish to honour Arnold Schwarzenegger’s leadership (as governor of California) in pioneering the reduction of carbon emissions, and for advising the Australian government to do the same ( Anonymous 2015).

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

Distribution:— Scattered through mallee districts from Eyre Peninsula and the southern Flinders Ranges in South Australia, through northern Victoria and as far north as Condoblin in New South Wales.

Habitat:— This species prefers clay soils on drier sites dominated by mallee eucalypts such as Eucalyptus odorata Behr (1847: 657) , E. polybractea Baker (1901: 692) and E. viridis . It appears to be long-lived (Brewer 025) and able to survive in disturbed sites such as roadsides.

Conservation status:— Although geographically widespread, this species is known almost entirely from roadside remnants in country cleared for growing wheat, and so is probably threatened.

Selected specimens (17 examined):— Approximate locality data are given because the species is rare. SOUTH AUSTRALIA. Eyre Peninsula: Hundred of Campoona , 33°30’S, 136°30’E, M . Bennell & D. Canty DEP 5495, 30 October 1986 ( AD). Lofty North: N of Jamestown , 33°00’S, 138°40’E, M. G . Catford s.n., October 1975 ( AD, CBG 60426 , K, MEL, W); ibid., M . D. Crisp 9425 & L. G . Cook, 17 September 2002 ( AD, CANB) .

Murray Basin: vicinity of Burra Gorge, 33°50’S, 139°00’E, A. C . Spooner 6459, 18 August 1979 ( AD); ibid., K. H . Brewer 025, 24 December 2005 ( AD). Kangaroo Island : Kingscote, J. G. O . Tepper s.n., 1880s ( AD 97622061 C, MEL 80962 A). VICTORIA. Northern Plains : Near Wychitella, 36°20’S, 143°40’E, A. C . Beauglehole 69324, 21 October 1981 ( CANB, MEL); near Rushworth , 36°40’S, 145°E, G. W . Carr s.n., 14 October 1979 ( AD, CANB 7910821 , LTB, MEL); ibid., M. E . Phillips, 29 October 1961 ( CBG); W of Rushworth , 36°30’S, 145°E, M . D. Crisp 9558 & L. G . Cook, 19 Oct 2002 ( CANB); near Tatura , 36°30’S, 145°10’E, E . Gauba, 2 October 1955 ( CANB) ;

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Whipstick Scrub, N of Bendigo , 36°40’ 144°20’E, M. E . Phillips s.n., 11 October 1966 ( CBG 19043 ). Western Highlands: Grampians , 37°10’S, 142°30’E, H. B. W [illiamson] s.n., December 1899 ( CANB 318263 ). NEW SOUTH WALES. Central West Slopes: Near Tallimba , 34°00’S 146°50’E, W . McReadie , October 1962 ( CANB); W of West Wyalong, 33°50’S, 147°E, J. W . Wrigley 71/213, 15 December 1971 ( CBG 435216 ) .

Affinity:— This species was previously included in D. benthamii as subsp. humilis , but here we divide this subspecies into two cryptic species ( D. devito and D. schwarzenegge r), which DNA sequences have shown to be reciprocally monophyletic and more closely related to other species than to each other or to D. benthamii ( Fig. 1B ). Daviesia devito is distinguished from its cryptic twin D. schwarzenegger by having minute (ca. 1 mm) triangular, dark red stipules, ribbed rather than wrinkled branchlets and phyllodes (when dry), and a more slender, less robust appearance overall. Daviesia benthamii s.s. is restricted to the central wheatbelt of Western Australia and northwards. It has a similar vegetative appearance to D schwarzenegger but the phyllodes increase in length downwards from the branchlet tip to 50 (100) mm long, with the lower third of the branchlet abruptly leafless. Daviesia aphylla (previously named as D. benthamii subsp. acanthoclona ) overlaps in distribution with D. schwarzenegger in central-eastern South Australia but no closely adjacent populations are known. It differs from D. schwarzenegger in its tall habit (1–3 m) and non-glaucescent branchlets that are almost leafless or have short (<20 mm) phyllodes confined to the upper few nodes of the branchlets. Daviesia genistifolia can be confused with D. schwarzenegger but differs in having the phyllodes articulate at the branchlet.

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 74. Daviesia schwarzenegger. A. Fruiting branchlet. B. Detail of phyllode and pod (stipule absent). Daviesia devito. C, D. Detail of phyllodes with pods, showing minute triangular stipule just below axil. E. Calyx opened out, upper lobes at left. F. Standard. G. Wing. H. Keel. I. Seed with aril, lateral view. J. Same, hilar view. A, B from Wrigley 71/213 (CBG 435216), C from Phillips s.n. (CBG 3199); D from Tepper s.n. (MEL 80962), E–H from Crisp 931, I, J from Tepper s.n. (AD 97622061C). Drawn by M.D. Crisp, except C by A.L. Prowse. Adapted from Crisp (1980a) with permission from the Board of the Adelaide Botanic Gardens.