Gastrolobium argyrotrichum  |  

Gastrolobium argyrotrichum

Status: Critically Endangered on the EPBC Act list

Erect shrubs to 1.5 m tall but more usually c. 1 _ 1 m. Branchlets ascending, distinctly angular to
subterete, densely sericeous. Petioles terete, continuous and decurrent with the branchlet, 1.5Ð3 mm
long. Leaves patent to variously antrorse, in whorls of 3 (occasionally opposite or in whorls of 4),
oblong to obovate, 10Ð30 _ (4Ð)7Ð13 mm; apex shallowly emarginate to conspicuously bilobed, or
almost truncate with flared lateral lobes, with a recurved, terminal mucro to 2 mm long and often also
with short, fragile mucros, to 0.2 mm long, on the lateral lobes; margins undulate, recurved, thickened
and minutely papillose; base rounded; upper surface with prominently reticulate and raised venation
bearing minute papillae, scattered hairs usually present along the midrib; lower surface very densely
sericeous. Stipules erect to recurved, linear-subulate, 4Ð6.5 mm long, sericeous. Inflorescences
condensed, terminal (more rarely axillary), racemose, c. 6Ð20-flowered; peduncle 1Ð5 mm long,
densely sericeous; rachis 2Ð10 mm long; subtending bracts caducous, 4.5_6 mm long, the lowest
prominently trifid, the remainder entire or the margin distantly toothed, densely sericeous. Pedicels
terete, 1.5Ð3 mm long, densely sericeous. Calyx campanulate, 5.5Ð6 mm long, including the c. 2.5 mm
long receptacle, densely sericeous (the indumentum including some spreading hairs), hairs bicoloured,
silky-white in the basal half becoming golden brown towards the apex; upper 2 lobes united higher
than the lower 3, ± spreading, triangular, subacute, 2Ð2.3 mm long; lower 3 lobes erect, narrowly
triangular, acute, 3.2Ð3.5 mm long. Corolla: standard limb transversely elliptic, 7Ð10 mm long including
the 2.2Ð3 mm long claw, 7Ð10 mm wide, yellow with a dark red ring surrounding the yellow centre,
apex emarginate or rounded, base ± truncate; wings 6.5Ð8.5 mm long including the 2.2Ð3 mm claws,
2.2_3.5 mm wide, yellow with dark red markings toward the base, apex rounded, incurved and
overlapping to enclose the keel, base auriculate; keel 7.3Ð8.5 mm long including the 2.2Ð3 mm claws,
2.8Ð3.5 mm wide, dark red, apex rounded, base auriculate, saccate. Style c. 4Ð5 mm long, incurved,
lower portion pubescent; ovary shortly stipitate, densely pubescent, 4-ovulate. Young pods shortly
stipitate, ovoid, moderately to densely pubescent. Mature seeds not seen. (Hislop et al. 2014).

Government evidence of impact of climate change:

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  • Australian Government, Conservation Advice, Gastrolobium argyrotrichum

    The valley habitat is considered a fire risk by local residents; with a drying climate and this area being particularly fire prone; there is the possibility of frequent fire that may not only affect the species reproductive capacity but may also facilitate spread and exacerbation of the existing weed infestation.

    Does the species use refugia Granite outcrops are considered to be important as localized refugia where species have persisted in the microhabitats offered during times (include what is it and when is it used) anthropogenic climate change.

    The throughout the state and the larger country it is population 2. impact of fire on the highly likely that there will be pressure for more With a drying climate and the actual species is frequent fire in these such areas. sub populations being close to unknown.

    Habitat quality will decline through weed spread within sub population 2 and there is the risk that this may be enhanced by a more frequent fire regime resulting from community pressure.

    Habitat quality will continue to decline through weed spread within sub population 2 and there is the risk that this may be exacerbated by a change to a more frequent fire regime.

    With the increasing pressure for fire in sub population 2; there is the potential that a single fire event or multiple short rotation fire events could remove 60 of the species extent.

    Clearing part of this sub population extends onto undeveloped private property; clearing associated with future development of this property is a threat A change in fire regime to short interval fire without consideration of reproductive maturity is a future threat.

    At how many locations does the One species occur (The two sub populations are 1.5km apart; but linked by continuous forest and may be threatened by a single fire event.

    Annual weeds are particularly responsive to regular fire and as such any change to a more frequent fire regime may accelerate this degradation.

    A change in fire regime This threat is Both sub populations of Both sub populations are within what is A threat from altered fire regime particularly relevant to the species are long considered a very high fire risk area with semi is a future threat.

    While it may houses it is likely that both (in promote seedling particular sub population 2) will recruitment there is the be subject to either a changed possibility that it may fire regime and or vegetation not or that too frequent modification to mitigate a fire may result in species perceived fire risk. loss without a consideration of There is a risk that any fire reproductive maturity. regime introduced may involve frequent fire without Increased weed invasion consideration of the species is a major risk from fire; reproductive maturity.

    Burning particularly if it is too prior to the species producing frequent and facilitates adequate seed for population annual weed growth. replacement will result in a Annual weeds are decline in the population. already established in With annual weeds already sub population 2 any established in sub population 2 proliferation of them there is the future threat that may out compete native frequent fire will exacerbate seedlings resulting in weed populations resulting in species loss and habitat habitat degradation. degradation.

    There is the risk that a fire event may both fail to promote seedling germination and adversely impact mature plants.

    As such until the species fire ecology is known any change to the current fire regime is a risk.