Acacia lobulata
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Contents
General Plant Info
Acacia lobulata, "The Chiddarcooping Wattle", is an erect, open and often spindly shrub, 1-2 m high with yellow, globular flower heads, smooth bark, with branchlets that are slightly angled, warty and resinous.
First discovered in 1985, and formally named in 1991, the specific name lobulata refers to the surface of the phyllodes. Acacia lobulata has an impressed net-nervature of phyllodes with the areoles raised, giving the phyllodes a regular cobblestone appearance.
In 1988 a second population was located on private property near Yanneymooning Hill. This portion of the property was later reserved as part of a land swap. A third population was located by Marcelle Buist in September 1999. It occured on a roadside and in adjoining property.
Acacia lobulata was declared as Rare Flora in 1997, and listed as Endangered (Wildlife Conservation Act 1950 (Western Australia): September 2013)
A member of the ‘Acacia flavipila group’, this species is closely related and morphologically similar to Acacia verricula
It is the only known species of Acacia in Australia with terete phyllodes having reticulate venation, unlike Acacia verricula, which has flat phyllodes, more flowers per head, and free sepals, but quite similar fruits and seeds.
Geographic distribution
This species is known from the Chiddarcooping Hill area near Warralakkin, about 70 km NE of Merredin in the NE Wheatbelt of SW WA (Buist et al. 2000), with a geographic range of 17 km. (Mollemans et al 1993; Brown et al. 1998)
The relatively recent discovery of a new population increased the known range of the species to 20 km, and the total number of populations to three (Buist et al. 2000). Previously the species was known by two populations with a geographic range of 17 km (Mollemans et al 1993; Brown et al. 1998).
Two populations, with plant numbers exceeding 5000, occur in nature reserves (Buist et al. 2000; Buist et al. 2002) including Chiddarcooping NR (Cowan & Maslin 1990; Briggs & Leigh 1996). The third population, of 116 plants, occurs essentially on a shire road reserve, but extends into adjacent private property. The taxon is highly restricted but locally abundant (Buist et al. 2000; Buist et al. 2002).
It is presumed to be a relict species (Buist et al. 2000).
Beard’s Provinces: Eremaean Province, South-West Province.
IBRA Regions: Avon Wheatbelt, Coolgardie.
IBRA Subregions: Avon Wheatbelt P1, Southern Cross.
Local Government Areas (LGAs): Nungarin, Westonia, Yilgarn.
Identification
Bark smooth. Branchlets slightly angled, tuberculate, glabrous, resinous. Stipules not seen, apparently absent.
Phyllodes are asymmetrical, ascending, with dull, grayish-green, strong, excentrically incurved, acute tips. 0.5mm long pulvinus (1-5)25-30(-35)mm long, 0.7-0.8 mm diam; nerves resinous, impressed, forming a coarse, regular reticulm, areoles raised markedly. Gland circular, brownish, depressed in centre, situated on upper surface of phyllode 0.5-2 mm above pulvinus. Peduncles(2.5-)3-4.59-6) mm long, solitary, occasionally in pairs, puberulous; basal peduncular bracts ovate, slightly concave, acute.
Inflorescence are globular, solitary flower heads, composed of between 15 and 17 flowers, 3.5 mm by 4.5 mm in diameter, appearing in June-July (Hopper et al. 1990). Bracteoles spathulate to obovate-spathulate, blade ovate to lanceolate, puberulous, ciliolate. Flowers 5-merous. Sepals less than half to about half as long as the petals 1/3-1/2-united, oblong, ciliolate. Petals narrowly elliptic, acute, free, glabrous. Ovary densly white pilose.
Pods linear, raised over but not constricted between seeds, 40-60 mm long, 3-4 mm wide, thin-chartaceous, strongly curved, smooth, glabrous, resinous. Seed longitudinal, oblong, compressed, 4-5.5 mm long, 1.8-2.3 mm wide, dull dark-brown; pleurogram narrowly oblong, 2/3 seed length; aril membranous, apical, more than half as long as seed.
Seeds are longitudinal, oblong, compressed, 4-5.5 mm long, 1.8-2.3 mm wide, dull dark brown. The species flowers in July and fruits in November.
Alkaloid content
This species is classified RARE. DO NOT harvest this species please!
Other uses
Extraction
Cultivation
Acacia lobulata occurs exclusively on colluvial quartz gravel loam of decaying kaolinite granite. The soil type is in close proximity to large granite outcrops and laterite breakaways.
All populations show an absence of recruitment. The species relies on fire to drive its population dynamics. Ants disperse Acacia lobulata seed (Buist 2003).
It was found that Acacia lobulata plants take three seasons to produce flowers following germination.
Suppliers
A number of seedlings have been grown in the Botanic Gardens and Parks Authority nursery for research purposes.
Links
http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=55567
https://florabase.dpaw.wa.gov.au/browse/profile/12263
http://www.worldwidewattle.com/speciesgallery/lobulata.php
