Acacia mutabilis Maslin, Nuytsia 12: 371 (1999)
Shrub 0.3–2 m high. Branchlets glabrous or with minute, straight, appressed hairs commonly restricted to phyllode axils. Stipules caducous or persistent. Phyllodes variable, frequently linear to oblanceolate, straight to incurved or recurved, flat to subterete or obtusely pentagonal, 1.5–5.5 cm long, 1–8 mm wide, acute to obtuse, mucronate or apiculate, coriaceous, green to grey-green, sometimes glaucescent in subsp. angustifolia , glabrous but pulvinus mostly appressed-puberulous adaxially, 5-nerved in all, prominently 1-nerved per face when flat; adaxial margin with 2 nerves coalescing above the gland commonly in basal 1/3–1/2 of phyllode but sometimes free to apex; gland 1–15 mm above pulvinus. Inflorescences rudimentary, normally 2-headed racemes with axes <0.5–1 mm long; peduncles 3–18 mm long, glabrous, rarely strigulose; heads globular, 4–5 mm diam., 16–32-flowered, golden. Flowers 5-merous; sepals free. Pods (not seen for subsp. rhynchophylla ) slightly or not at all constricted between seeds, curved to once-coiled, terete, to 7 cm long, 2–3 mm wide, thinly coriaceous, black, glabrous or sparsely strigulose. Seeds (not seen for subsp. angustifolia or rhynchophylla ) longitudinal, oblong, 3–4 mm long, shiny, black; aril terminal, conical, white or dull yellow.
Occurs in southern W.A. from Gnowangerup E to the western extremity of S.A. near Eucla.
Very variable in phyllode morphology with five subspecies recognised, mostly on phyllode shape and proportions, stipule persistence and peduncle length.
Allied most closely with A. halliana , A. merrallii , A. simmonsiana and A. nitidula .
Key
1 Phyllodes 1–2 mm wide, subterete to obtusely pentagonal, rarely flat
subsp. angustifolia
1: Phyllodes 3–8 mm wide, flat
2 Phyllodes obtuse and excentrically rostriform (mucro lateral to sublateral), 4–8 mm wide
subsp. rhynchophylla
2: Phyllodes acute or obtuse, often excentrically narrowed at apex but mucro not lateral or sublateral
3 Phyllodes distinctly incurved, gland 1–5 mm above pulvinus; peduncles 3–6 mm long
subsp. incurva
3: Phyllodes straight to shallowly recurved or if shallowly incurved then gland further from pulvinus and/or peduncles longer
4 Stipules persistent, 2–3 mm long, 0.5–0.7 mm wide
subsp. stipulifera
4: Stipules caducous or if persistent (rare), then c. 1 mm long and 0.2–0.3 mm wide
subsp. mutabilis
Acacia mutabilis Maslin subsp. mutabilis
Shrub 0.3–1.2 m high. Stipules rarely persistent, c. 1 mm long. Phyllodes linear to linear-oblanceolate, obovate-oblanceolate or narrowly oblong-elliptic, usually straight to shallowly incurved, 1.5–5 cm long, 3–5 mm wide, l:w = (3- ) 5–14; gland 5–15 mm above pulvinus. Peduncles 5–10 mm long.
Occurs from Kordinin- Borden area E to Cape Arid Natl Park (E of Esperance), south-west W.A. Grows in sand, sandy clay, clay, loam and sandy loam, in heath, open shrub or tree mallee and as understorey in open eucalypt woodland, often at the periphery or near salt lakes or marshes, mostly in flatlands.
Phyllodes very variable in shape and size: shallowly recurved phyllodes occur near Truslove (c. 60 km due N of Esperance) and specimens with unusually short phyllodes occur E of Ravensthorpe and in the Mt Madden- Lake King area (N of Ravensthorpe). Specimens with shallowly incurved phyllodes differ from subsp. incurva in having longer peduncles and/or the gland farther removed from the pulvinus.
Type of accepted name
E of Scaddan, W.A., 7 Aug. 1970, K.M.Allan 355 ; holo: PERTH; iso: K.
Representative collections
W.A.: near Kau Rock, T.E.H.Aplin 4072 (CANB, PERTH); 8 km S of Lake King towards Ravensthorpe, B.R.Maslin 3437 (MEL, PERTH); 12.8 km SW of Borden, K.R.Newbey 1441 (PERTH); Gnowangerup, at golf course, J.W.Wrigley WA/68 4827 (PERTH).
Acacia mutabilis subsp. angustifolia Maslin, Nuytsia 12: 373 (1999)
Shrub 0.3–1.3 m high. Stipules caducous or if persistent then 3–5 mm long. Phyllodes narrowly linear, flat to subterete or obtusely pentagonal, 2–4.5 cm long, 1–2 mm wide, l:w = 12–30, the adaxial nerves free to apex, rarely coalescing; gland 7–15 mm above pulvinus. Peduncles 5–18 mm long.
Scattered distribution within 100 km of the S coast from near Jerramungup, W.A. E to far western S.A. near Eucla. Grows in calcareous loam or sand with clay, sometimes with limestone nodules, in low open woodland or open shrub mallee.
Two variants are recognised and may upon further study be shown to be distinct taxa: in the western part of the range (including the type) most specimens have persistent stipules and flower-heads (6–) 7–8 mm diam. at anthesis; specimens from farther east have mostly caducous stipules and slightly smaller flower-heads (5–6 mm diam.).
Resembling A. gonophylla ; also similar to A. pachyphylla which has dimorphic, 4-nerved phyllodes, solitary, larger heads with more flowers and much wider, hard, bony pods. Acacia quinquenervia has similar phyllodes except that they are obviously hairy (at least when young) and has normally densely hairy branchlets, simple inflorescences and mottled seeds. Acacia pinguifolia (S.A.) superficially resembles this subspecies.
Type of accepted name
Parmango Rd adjacent to Clyde Hill (which is c. 120 km due NE of Esperance), W.A., 16 Aug. 1985, B.R.Maslin 5824 ; holo: PERTH.
Illustration
D.J.E.Whibley & D.E.Symon, Acacias S. Australia 2nd edn, 115 (1992).
Representative collections
W.A.: Twilight Cove, Great Australian Bight, A.S.George 8566 (PERTH); 24 km NNE of Jerramungup, K.Newbey 4818 (G, K, NSW, NY, PERTH). S.A.: 3.5 km E of W.A.- S.A. border [on the Eyre Hwy], R.J.Chinnock 3346 (AD, PERTH).
Acacia mutabilis subsp. incurva Maslin, Nuytsia 12: 374–375 (1999)
Shrub 1.6–2 m high. Stipules occasionally persistent, c. 2 mm long, c. 0.3 mm wide. Phyllodes subdistant, linear-oblanceolate, incurved, 3–5.5 cm long, 3–4 mm wide, l:w = 8–13; gland 1–5 mm above pulvinus. Peduncles 3–6 mm long.
Known only from the Ongerup- Pingrup area (Pingrup is c. 45 km N of Ongerup), south-west W.A. Grows in loam over clay in low woodland of Eucalyptus spathulata or open shrub mallee with E. transcontinentalis .
Plants of this subspecies are the tallest in the species.
Type of accepted name
SE of Pingrup [precise locality withheld for conservation reasons], W.A., 1 Sept. 1975, K.R.Newbey 4774 ; holo: PERTH; iso: CANB, K.
Representative collection
W.A.: Ongerup area, K.Newbey 3010 (MEL, NSW, PERTH).
Acacia mutabilis subsp. rhynchophylla Maslin, Nuytsia 12: 375 (1999)
Shrub 0.5–1 m high. New shoots appressed-puberulous, the hairs pale yellow and white. Stipules subpersistent, 0.5–1.5 mm long. Phyllodes oblanceolate, straight to shallowly recurved, 2–3 cm long, 4–8 mm wide, l:w = 3–7, rounded-obtuse, excentrically rostriform; gland 4–6 mm above pulvinus. Peduncles 3–7 mm long.
Occurs from the Nyabing- Pingrup area S to Borden (N and E of Ongerup), south-western W.A. Grows in gravelly sand, sandy loam or loam, in open shrub mallee with Eucalyptus redunca and E. transcontinentalis.
The specimen A.M.Ashby 4680 is slightly atypical in that its mucro is less lateral than normal. Acacia mutabilis subsp. rhynchophylla is most readily distinguished from other subspecies by its obtuse phyllodes with lateral to sublateral mucro, resembling a bird’s head.
Type of accepted name
14.1 km SE of Nyabing, W.A., 29 Sept. 1970, B.R.Maslin 796 ; holo: PERTH; iso: K, MEL, NSW, PERTH.
Representative collections
W.A.: c. 170 km from Albany on Borden- Pingrup road, A.M.Ashby 4680 (AD, CANB, G, K, MEL, NY, PERTH); Pingrup, W.E.Blackall 3111 (PERTH); 16 km SW of Borden, K.Newbey 1442 (PERTH).
Acacia mutabilis subsp. stipulifera Maslin, Nuytsia 12: 376 (1999)
Shrub 0.3–1 m high. Stipules persistent, stout, 2–3 mm long, 0.5–0.7 mm wide. Phyllodes narrowly elliptic to narrowly oblong-elliptic or oblanceolate, straight, 2–5 cm long, 4–8 mm wide, l:w = 4–10, acute or obtuse, rather rigid; gland 5–10 mm above pulvinus. Peduncles 4–12 mm long.
Localised S of Newdegate near L. Bryde and L. Cobham, south-west W.A. Grows in loamy sand and clay usually on slightly saline soil within salt lake systems, in low woodland of Eucalyptus kondinensis and E. occidentalis .
Caducous and/or smaller stipules characterise the other subspecies, except for subsp. angustifolia which has the narrowest phyllodes in the species. Has similarities to a taxon of uncertain rank which resembles A. halliana (see under A. halliana ).
Type of accepted name
Lake Cobham area [precise locality withheld for conservation reasons], W.A., 17 Aug. 1970, K.R.Newbey 3263 ; holo: PERTH; iso: CANB, K, MEL, PERTH.
Representative collections
W.A.: S of Newdegate, B.R.Maslin 3861 (PERTH); type locality, K.Newbey 3263A (PERTH).
(BRM)
The information presented here originally appeared on the WATTLE CD-ROM which was jointly published by the Australian Biological Resources Study, Canberra, and the Department of Parks and Wildlife, Perth; it was produced by CSIRO Publishing from where it is available for purchase. The WATTLE custodians are thanked for allowing us to post this information here.
