Diurus aequalis F. Muell. ex Fitzg. (family Orchidaceae) is described by PlantNET(2018) as
ÒTerrestrial herb. Leaves 2, linear, 10Ð20 cm long, 3Ð4 mm wide, conduplicate. Raceme 20Ð45 cm
high, 2Ð5-flowered. Flowers golden yellow to orange, usually unspotted, c. 2.5 c. across. Dorsal sepal
broad-ovate to circular, 7Ð10 mm long, 8Ð15 mm wide, erect. Lateral sepals linear to oblanceolate,
8Ð13 mm long, 2Ð3 mm wide, falcate, green. Petals erect, widely divergent; lamina elliptic to
circular, 6Ð10 mm long, 4Ð6 mm wide; claw 4Ð6 mm long, green. Labellum 5Ð6 mm long; lateral
lobes narrowly to broadly cuneate, 5Ð9 mm long, 2.5Ð5 mm wide; midlobe broad-cuneate when
flattened, c. 7 mm wide, ridged along midline; callus of 2 broad, incurved ridges c. 3.5 mm long.Ó
buttercup doubletail |
Diuris aequalis
Status: Endangered on the EPBC Act list
Government evidence of impact of climate change:
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Australian Government, Conservation Advice, Diuris aequalis
For example; distribution of Diuris aequalis overlaps with that of EPBC listened threatened ecological communities White Box Yellow Box Blakely’s Red Gum Grassy Woodland and Derived Native Grassland; 66 97 cleared; ongoing threats leading to deterioration including via grazing; weeds; fire (TSSC 2006) Natural Temperate Grassland of the Southern Tablelands of NSW and the Australian Capital Territory; 90 cleared; ongoing and demonstrable threats including fragmentation; grazing; nutrient enrichment; fire; weeds (TSSC 2016).
Drought and fire impacts Diuris aequalis may also be threatened by drought and the interaction of drought and fire.
In addition; some 30 60 of the known distribution of the species was estimated to have been burnt in the 2019 2020 fires (Gallagher 2020; Auld et al. 2020) and there was a high risk to post fire recovery from the combination of pre fire drought and post fire herbivory (Auld et al. 2020).
Finally; Auld et al. (2920) identified pre fire drought and post fire herbivory as threats to recovery after the 2019 2020 fires. c) Extreme fluctuations.
The main reasons for this Diuris aequalis being eligible are that i) the species has highly restricted geographical range with an area of occupancy of 132 km2 ii) it is considered to be severely fragmented and iii) declines have been suspected in the number of mature individuals at some sites; and decline is projected to result from ongoing threats; including grazing; drought and demographic stochasticity (i.e; because of the small numbers of plants in many populations) .
Drought and fire impacts Diuris aequalis may also be threatened by drought and the interaction of drought and fire.
This includes impacts of drought from the past 10 years and also predicted future decreases in spring and winter rainfall in the southern part of the distribution (K.
In addition; some 30 60 of the known distribution of the species was estimated to have been burnt in the 2019 2020 fires (Gallagher 2020; Auld et al. 2020) and there was a high risk to post fire recovery from the combination of pre fire drought and post fire herbivory (Auld et al. 2020).
Finally; Auld et al. (2920) identified pre fire drought and post fire herbivory as threats to recovery after the 2019 2020 fires. c) Extreme fluctuations.