Morphological and molecular evidence refute a broad circumscription for Pultenaea glabra (Fabaceae: Mirbelieae), with implications for taxonomy, biogeography, and conservation
Author
Renner, Matthew A. M.
Author
Barrett, Russell L.
Author
Clarke, Steve
Author
Clugston, James A. R.
Author
Wilson, Peter H. Weston Trevor C.
text
Australian Systematic Botany
2022
2022-07-14
35
3
225
277
http://dx.doi.org/10.1071/sb21030
journal article
10.1071/SB21030
1446-5701
11048683
3.
Pultenaea tenebrosa
M.A.M.Renner, P.H.Weston & S.Clarke
,
sp. nov.
Pultenaea
sp.
Wolgan
Cliffs
(
S
.Clarke 602)
NSW
Herbarium,
PlantNet
[https://plantnet.rbgsyd.nsw.gov.au/ accessed
22 Feb. 2022
]
.
Type
:
New South Wales
,
Central Tablelands
,
Wolgan State Forest
,
Site
2, ~
23 km
NNW of Lithgow
,
8.5 km
NE
of
Cullen Bullen
, cliffs on western rim of
Wolgan Valley
,
9 Nov. 2014
,
S
.
Clarke 602 (holo:
NSW 883692
)
.
Diagnosis
Distinct in its linear leaves that spread at right angles to the stem, the abaxial leaf surface with bulging cells that bear fine granular ornamentation, the red–brown to black stipules whose lobes are divergent and recurved and completely obscure the branchlets, the calyx with long spreading hairs and coriaceous, pungent, bracteoles that extend as far as, or further than, the adjacent calyx lobe apices.
Spreading multi-stemmed shrub upto 2.0 m tall, peripheral branches nearly horizontal, initiating new branches at base. Branching furcate to fasciculate, irregular. Larger branches and trunk grey–brown with ruminant red–brown traces that become more prominent with branch size. Branchlets yellow–green, almost completely obscured by red–brown recurved stipules.
Stipules
red–brown aging to dark brown or black, imbricate, furcate, divided for half their length, lobes divergent, sometimes recurved, through as much as 180°; lobe apex acuminate; lamina margins irregularly toothed along their length, the teeth poorly formed but distinct, rounded or acute; stipule lobes eccentrically keeled, the wing on the outside of the keel wider than the inner.
Leaves
linear to nearly terete, 5.7–16.6 (average 11.1) mm long by 0.4–0.8 (average 0.5) mm wide, spreading at right angles from the stem, dull to mid-green with a hint of yellow below, narrow, inrolled but not completely enclosing the adaxial surface, glabrous; adaxial surface green with a glaucous wash, low pill-box papillae present; abaxial surface discolourous, green laterally (on the surface presented dorsally), red–brown medially (the surface presented ventrally), with a lighter tan–brown central stripe where the midvein is visible; apex tapered to a short point, red–brown; leaf anatomy with ventral epidermal cells hyaline, larger on abaxial surface, subepidermis of orange-pigmented cells present on ventral leaf, three vascular traces present, median trace largest and abutting the orange-pigmented subepidermis; abaxial leaf epidermal cells bulging but not mamillose, bearing granular ornamentation.
Inflorescence
with flowers closely spaced, but internodes not contracted, with leaves among the flowers progressively decreasing in size at sequential nodes, the shoot continues vegetative growth after flowering; stipules subtending floral leaves similar to sterile stipules, but a little shorter and broader.
Flowers
sessile.
Calyx
outer surface with long spreading hairs, the inner surface of each lobe discolourous, margins brown, green below; ventral lobes narrower than the two dorsal lobes, floccose along their median line; the two dorsal lobes floccose along submarginal lines; lobes sometimes bearing scattered hairs on outer surfaces; calyx tube with an indistinct ring of hairs encircling the top of the tube, beneath the sinuses.
Bracteoles
conspicuous, coriaceous, pungent, weakly keeled, with an indistinct hyaline margin, extending to, or slightly beyond, the level of the calyx lobe apices.
Corolla
orange–yellow with a faint red flare at the base of standard, keel darker orange–yellow than standard; standard broadly obovate, concave at flower maturity, wings loosely overlaying keel, ligulate above a narrow stipe, almost narrow rectangular with upper and lower margins nearly parallel, apex rounded, base with broad angular auricle; keel asymmetrically elliptic–obovate, upper margin curved, lower margin evenly curved, deepest just beyond mid point towards apex, apex broadly rounded, basal auricle broadly triangular with a rounded apex.
Anthers
cream, filaments pale orange in dried state.
Pollen
cream.
Ovary
and style glabrous (
Fig. 15
,
16
).
Distribution and ecology
Pultenaea tenebrosa
is known from the Wolgan Valley, on the cliff complexes on the western side of the valley, and the pagoda-gully complexes on the Sunnyside Plateau on the south-eastern side. The habitat occupied by
P. tenebrosa
is challenging to access, and the species may be more widely distributed in suitable situations associated with the Wolgan Valley than current records indicate. The initial site on the eastern side of the Wolgan Valley was a chance discovery, and all subsequent sites were located during targeted searches of pagoda habitats in the area. On the western cliff lines of the Wolgan Valley,
Pultenaea tenebrosa
occurs almost exclusively on ledges immediately below Mount
York
claystone. Claystone ledges on the eastern side were also searched with no results, so it seems it occurs on such ledges on the western side of the Wolgan Valley only. The ledges below Mount
York
claystone on the western cliff-lines bear a sparse canopy of
Eucalyptus
sp.
(
piperita
?), and usually a dense heathy understorey. including
Acacia obtusifolia
,
Allocasuarina
sp.
,
Banksia penicillata
,
Banksia spinulosa
,
Dracophyllum secundum
,
Gahnia filifolia
,
Leptospermum polygalifolium
,
Styphelia mutica
,
Styphelia sieberi
,
Persoonia myrtilloides
,
Philotheca obovalis
,
Epacris reclinata
and
Xanthorrhoea
sp.
The soils at these sites are sandy loams or sandy clays.
In three of the populations on the western side of the Wolgan Valley, all plants present pre-fire appear to have been killed outright by the Gospers Mountain fire over the summer of 2019–2020. No basal or epicormic resprouting was seen on any of the charred skeletons of pre-fire adults that could still be identified. However, by
June 2020
, there had been a large flush of post-fire seedling emergence across the sites, with the largest some
15–20 cm
tall at
5 June 2021
(
Fig. 17
). Two sites had at least 100–200 seedlings each, the third site had a modest 16. So, although the fire has resulted in a many-fold increase in the known number of individuals, it has reduced a significant adult proportion of the species, or perhaps the entire global population, given the entire known extent of the species was burnt, to the current crop of post-fire seedlings. This leaves the species particularly vulnerable in the event of another fire before the current cohort matures and reproduces to replenish the soil seed bank.
Recognition
Pultenaea tenebrosa
can be recognised by its combination of linear leaves that spread at right angles to the stem, and the red–brown to black stipules the lobes of which are divergent and recurved and completely obscure the branchlets. Two other distinctive features of
P. tenebrosa
are the long spreading hairs on the calyx and the coriaceous, pungent, bracteoles that extend as far as, or further than the adjacent calyx lobes.
Pultenaea tenebrosa
is similar to
P. furcata
, but the two can be distinguished by the leaf abaxial surface, which in
P. tenebrosa
bears bulging cells with fine granular ornamentation, whereas in
P. furcata
the cells each bear a low triangular mamilla. This character may be useful with sterile specimens whose stipules are not, or are suboptimally, recurved.
Fig. 15.
Pultenaea tenebrosa
(=
P.
sp. Wolgan Cliffs (
S. Clarke 602
)) line drawing. (
a
) Flowering branch detail; (
b
) habit; (
c
) stipule; (
d
) flower, lateral view; (
e
) flower, perianth removed, lateral view; (
f
) standard petal, ventral view; (
g
) wing, lateral view; (
h
) keel, lateral view; (
l
) leaf abaxial surface; (
j
) leaf, adaxial surface; (
k
) leaf cross section and adaxial surface; (
l
) leaf cross section and abaxial surface. Scale bar: 10 mm (
a
); 26.7 mm (
b
);
c
, 2.7 mm (
c
); 8 mm (
d–h
); 5 mm (
i
,
j
); 1.6 mm (
k
,
l
). All from NSW 1058844,
b
from dried material,
a
,
c–l
from spirit.
Conservation status
Pultenaea tenebrosa
may qualify for Critically Endangered under the
IUCN
criteria, given the extent of occurrence is ~
64 km
2
, the species occurs as small, highly fragmented populations, and the populations experience extreme fluctuations in the numbers of mature individuals. During the fires of 2019–2020, fires burnt over the entire range of this species, and killed all mature individuals at three populations on the western side of Wolgan Valley resurveyed in
June 2021
. Altered fire regimes and browsing by feral herbivores including goats and probably deer constitute the greatest threats to this species.
Etymology
From the Latin
tenebrosa
, dark, referencing the habit of this species to grow on sheer cliffs of southerly to south-easterly aspect, and the stems densely covered by red–brown to black stipules.
Specimens examined
NEW SOUTH WALES
:
Central Tablelands
:
Gardens of Stone National Park
: ~
21 km
N
of
Lithgow
, ~
14 km
E
of
Cullen Bullen
,
eastern flanks of Sunnyside Ridge
in steep gully running into un-named tributary of Carne Creek,
21 Oct. 2015
,
S. Clarke
703
, (
NSW 933334
);
21 Oct. 2015
,
S. Clarke
704
, (
NSW 933333
);
21 Oct. 2015
,
S. Clarke
705
, (
NSW 933332
);
21 Oct. 2015
,
S. Clarke
706
, (
NSW 933331
);
~
23 km
N
of
Lithgow
,
~
18 km
E
of
Cullen Bullen
, eastern side of ridge above an un-named tributary of Carne Creek,
7 Mar. 2015
,
S.
Clarke 612
, (
NSW 933307
);
17 Mar. 2015
,
S. Clarke
613
, (
NSW 933308
);
~
23.5 km
N
of
Lithgow
, ~
18.5 km
E
of
Cullen Bullen
, eastern side of ridge above an un-named tributary of
Carne Creek
,
17 Mar. 2015
,
S. Clarke
614
, (
NSW 933305
);
17 Mar. 2015
,
S. Clarke
615
, (
NSW 933306
);
~
23.5 km
N
of
Lithgow
, ~
18.5 km
E
of
Cullen Bullen
, eastern side of ridge in gully running into an un-named tributary of Carne Creek,
21 Oct. 2015
,
S. Clarke
707
, (
NSW 933330
);
21 Oct. 2015
,
S. Clarke
708
, (
NSW 933329
);
~
24 km
N
of
Lithgow
, ~
18 km
E
of
Cullen Bullen
, eastern side of ridge above an un-named tributary of Carne Creek,
26 May 2015
,
S. Clarke
623
, (
NSW 933296
);
26 May 2015
,
S. Clarke
624
, (
NSW 933297
);
~
29 km
N
of
Lithgow
, ~
12.5 km
NE
of
Cullen Bullen
, southern cliffline of narrow divide between Wolgan and Capertee valleys,
3 June 2015
,
S. Clarke
625
, (
NSW 933293
);
3 June 2015
,
S. Clarke
626
, (
NSW 933294
);
3 June 2015
,
S. Clarke
627
, (
NSW 933295
);
Wolgan State Forest
: ~
22 km
NNW of Lithgow
,
7.5 km
NE
of
Cullen Bullen
cliffs on western rim of
Wolgan Valley
,
9 Nov. 2014
,
S. Clarke
596
, (
NSW 883686
);
9 Nov. 2014
,
S. Clarke
597
, (
NSW 883687
);
9 Nov. 2014
,
S. Clarke
598
, (
NSW 883688
);
9 Nov. 2014
,
S. Clarke
599
, (
NSW 883689
);
9 Nov. 2014
,
S. Clarke
600
, (
NSW 883690
);
9 Nov. 2014
,
S. Clarke
601
, (
NSW 883691
);
9 Nov. 2014
,
S. Clarke
602
, (
NSW 883692
);
~
22 km
NNW of Lithgow
,
7.5 km
NE
of
Cullen Bullen
cliffs on western rim of
Wolgan Valley
,
7 Dec. 2014
,
S. Clarke
605
, (
NSW 883679
);
7 Dec. 2014
,
S. Clarke
606
, (
NSW 883683
);
7 Dec. 2014
,
S. Clarke
607
, (
NSW 883684
);
7 Dec. 2014
,
S. Clarke
608
, (
NSW 883685
);
~
24 km
N
of
Lithgow
,
10 km
NE
of
Cullen Bullen
, cliffs on western rim of
Wolgan Valley
,
12 Dec. 2014
,
S. Clarke
609
, (
NSW 883674
);
12 Dec. 2014
,
S. Clarke
610
, (
NSW 883675
;)
~
23 km
N
of
Lithgow
, ~
8.5 km
NE
of
Cullen Bullen
, cliff lines flanking western side of
Wolgan Valley
,
27 Sep. 2015
,
S. Clarke
654
, (
NSW 933317
);
27 Sep. 2015
,
S. Clarke
655
, (
NSW 933318
);
7 Sep. 2015
,
S. Clarke
656
, (
NSW 933319
);
~
23 km
NNW of Lithgow
,
8.5 km
NE
of
Cullen Bullen
cliffs on western rim of
Wolgan Valley
,
9 Nov. 2014
,
S. Clarke
603
, (
NSW 883693
);
9 Nov. 2014
,
S. Clarke
604
, (
NSW 883694
);
~
25 km
N
of
Lithgow
, ~
8 km
NE
of
Cullen Bullen
, ~
2 km
SE of Baalbone Gap
,
27 Sep. 2015
,
S. Clarke
657
, (
NSW 933309
);
~
24 km
N
of
Lithgow
, ~
10 km
NE
of
Cullen Bullen
, cliffs flanking western side of
Wolgan Valley
,
27 Sep. 2015
,
S. Clarke
665
, (
NSW 934289
);
~
24 km
N
of
Lithgow
, ~
10 km
NE
of
Cullen Bullen
, cliffs flanking western side of
Wolgan Valley
,
27 Sep. 2015
,
S. Clarke
666
, (
NSW 934290
);
27 Sep. 2015
,
S. Clarke
667
, (
NSW 934291
);
~
25 km
N
of
Lithgow
, ~
8 km
NE
of
Cullen Bullen
, ~
2 km
SE of Baalbone Gap
,
27 Sep. 2015
,
S. Clarke
658
, (
NSW 933310
);
27 Sep. 2015
,
S. Clarke
659
, (
NSW 933311
;)
27 Sep. 2015
,
S. Clarke
660
, (
NSW 933312
);
27 Sep. 2015
,
S. Clarke
661
, (
NSW 933313
);
27 Sep. 2015
,
S. Clarke
662
, (
NSW 933314
);
27 Sep. 2015
,
S. Clarke
663
, (
NSW 933315
);
27 Sep. 2015
,
S. Clarke
664
, (
NSW 933316
);
~
27.5 km
N
of
Lithgow
, ~
10.5 km
NE
of
Cullen Bullen
, ~
0.5 km
S
of
Mount Jamison
, southern cliff line of narrow divide
between Wolgan and Capertree
valleys,
9 May 2015
,
S. Clarke
620
, (
NSW 933298
);
9 May 2015
,
S. Clarke
621
, (
NSW 933299
);
9 May 2015
,
S. Clarke
622
, (
NSW 933300
);
Woolpack Gap
, ~
28.5 km
N
of
Lithgow
, ~
11 km
E
of
Ben Bullen
,
19 Aug. 2015
,
S. Clarke
649
, (
NSW 933321
);
19 Aug. 2015
,
S. Clarke
650
, (
NSW 933320
);
Woolpack Gap
, ~
28.5 km
N
of
Lithgow
, ~
11 km
E
of
Ben Bullen
,
19 Aug. 2015
,
S. Clarke
651
, (
NSW 933322
);
19 Aug. 2015
,
S. Clarke
652
, (
NSW 933323
);
19 Aug. 2015
,
S. Clarke
653
, (
NSW 933324
);
~
13 km
N
of
Lidsdale
, ~
8 km
NE
of
Cullen Bullen
, W side of
Wolgan Valley
,
14 Apr. 2014
,
S. Clarke
s.n.
, (
NSW 887775
);
Newnes State Forest
: ~
18 km
N
of
Lithgow
, ~
14 km
E
of
Cullen Bullen
, pagoda ridge above an un-named tributary of
Carne Creek
,
30 Apr. 2015
,
S. Clarke
616
, (
NSW 933301
);
30 Apr. 2015
,
S. Clarke
617
, (
NSW 933302
);
30 Apr. 2015
,
S. Clarke
618
, (
NSW 933303
);
30 Apr. 2015
,
S. Clarke
619
, (
NSW 933304
);
~
18 km
N
of
Lithgow
, ~
14 km
E
of
Cullen Bullen
, pagoda ridge above an un-named tributary of
Carne Creek
,
21 Oct. 2015
,
S. Clarke
710
, (
NSW 933327
);
21 Oct. 2015
,
S. Clarke
711
, (
NSW 933326
);
21 Oct. 2015
,
S. Clarke
712
, (
NSW 933325
);
~
22 km
N
of
Lithgow
, ~
18 km
E
of
Cullen Bullen
, eastern side of ridge running into an un-named tributary of
Carne Creek
,
25 Jun. 2015
,
S. Clarke
641
, (
NSW 933292
);
25 Jun. 2015
,
S. Clarke
642
, (
NSW 933291
);
~
22 km
N
of
Lithgow
, ~
18 km
E
of
Cullen Bullen
, running into an un-named tributary of
Carne Creek
,
25 June 2015
,
S. Clarke
643
, (
NSW 933427
;)
25 June 2015
,
S. Clarke
644
, (
NSW 933428
);
25 June 2015
,
S. Clarke
645
, (
NSW 933429
);
~
22 km
N
of
Lithgow
,
~
18 km
E of Cullen Bullen
. Near head of gully between pagodas running into an un-named tributary of
Carne Creek
,
21 Oct. 2015
,
S. Clarke
698
, (
NSW 933339
);
21 Oct. 2015
,
S. Clarke
699
, (
NSW 933338
);
21 Oct. 2015
,
S. Clarke
700
, (
NSW 933337
);
21 Oct. 2015
,
S. Clarke
701
, (
NSW 933336
);
21 Oct. 2015
,
S. Clarke
702
, (
NSW 933335
).
Ben Bullen State Forest
:
Cliff-line
on western side of
Wolgan Valley
, E of
Bicentennial National Trail
,
31 Oct. 2019
,
M.A.M. Renner
9182 &
S. Clarke
, (
NSW 1058839
);
31 Oct. 2019
,
M.A.M. Renner
9183 &
S. Clarke
, (
NSW 1058840
);
31 Oct. 2019
,
M.A.M. Renner
9184 &
S. Clarke
, (
NSW 1058841
);
31 Oct. 2019
,
M.A.M. Renner
9185 &
S. Clarke
, (
NSW 1058842
);
31 Oct. 2019
,
M.A.M. Renner
9186 &
S. Clarke
, (
NSW 1058844
);
31 Oct. 2019
,
M.A.M. Renner
9187 &
S. Clarke
, (
NSW 1058845
)
.