There’s gold in them thar hills! Morphology and molecules delimit species in Xerochrysum (Asteraceae; Gnaphalieae) and reveal many new taxa
Author
Collins, Timothy L.
Author
Schmidt-Lebuhn, Alexander N.
Author
Andrew, Rose L.
Author
Telford, Ian R. H.
Author
Bruhl, Jeremy J.
text
Australian Systematic Botany
2022
2022-06-09
35
2
120
185
http://dx.doi.org/10.1071/sb21014
journal article
10.1071/SB21014
1446-5701
10903939
Xerochrysum wilsonii
T.L.Collins
,
sp. nov.
Type
:
AUSTRALIA
:
Western Australia
:
Darling
:
Porongurup National Park
, upper slopes and summit of
Devils Slide
,
17 Dec. 2018
,
T.L. Collins
1160
(holo:
PERTH
!; iso:
CANB
!,
NSW
!,
NE 108019
!)
.
[
Xerochrysum macranthum auct
. non
(Benth.) Paul G.Wilson:
A.N. Schmidt-Lebuhn
et al
.,
Taxon
64(1): 105 (2015)
,
p.p
., populations of perennial plants in the Esperance, Jarrah Forest and Warren bioregions with mid-cauline leaves ≥
12 mm
wide only].
Diagnosis
Distinguished from
X. macranthum
by a perennial life form (
v.
annual
or biennial), cauline leaves
10–20 mm
wide (
v.
5–12 mm
), capitula
40–60 mm
wide (
v.
30–50 mm
wide).
Erect or occasionally decumbent, taprooted, perennial shrub-like herb,
30–180 cm
in length.
Stems
and
branches
cobwebby to hispid, scabrid, and with glands; internode length
15–50 mm
.
Basal leaf rosette
absent at flowering.
Basal leaves
spathulate,
80–160 mm
long and
20–30 mm
wide, base amplexicaul, margin cobwebby to pilose, and hispid; apex apiculate; abaxial indumentum pilose and with glands, midvein indumentum pilose and with glands; adaxial indumentum hispid, pilose, and with glands.
Cauline leaves
oblanceolate,
60–110 mm
long and
10–20 mm
wide, base amplexicaul, margin cobwebby, hispid, and scabrid, apex mucronate;
abaxial indumentum
with sessile glands and scattered septate trichomes; midvein indumentum hispid, scabrid, and with glands;
adaxial indumentum
hispid, scabrid, and with glands.
Foliaceous bracts subtending capitula
~
10 mm
long, margin cobwebby and hispid.
Capitula
40–60 mm
wide, terminal, in panicles.
Outer phyllaries
broad-ovate, pink, white, or straw-coloured; basal margin fimbriate and hispid, abaxial surface smooth, apex apiculate.
Medial phyllaries
narrow ovate to elliptic, abaxially white, apex cuspidate.
Stylar appendages
ovate.
Cypsela
oblong, ~
2.1 mm
long and
0.9 mm
wide, cross-section squarish or circular; pericarp brown, idioblasts present.
Pappus
deciduous, ~
7–8 mm
long.
Fig. 44. Isotype of
Xerochrysum wilsonii
(
T.L.Collins 1160
, NE 108019).
Distribution
Endemic to the far south-west of
Western Australia
and recorded in the Esperance, Jarrah Forest and Warren bioregions (
Fig. 43
).
Phenology
Recorded flowering November–January and fruiting December–February (
Fig. 44
).
Habitat
Occurring in diverse habitats from montane heath and scree slopes at ~1000-m altitude to coastal heath near sea level, on skeletal sandy soils.
Conservation status
All known populations occur in conservation reserves, but appear to be restricted to specific habitats. We recommend a status of ‘
Data Deficient
’ (
IUCN 2019
) and suggest that a detailed analysis of the area of extent be conducted to determine appropriate conservation status.
Notes
At Toolbrunup
in
Stirling
Range National Park
, large plants up to
1.8 m
in length were seen decumbent across the scree-slope below the summit, with stem diameters up to ~
100 mm
.
Occasional
plants have been recorded at lower elevations (e.g.
J.R. Wheeler
4022
(
PERTH
!)), possibly owing to flower picking and subsequent discarding by bushwalkers; however, these lowland populations in
Stirling
Range National Park
do not appear to persist (
T. L. Collins
, pers. obs., 2018).
The
informal phrase-names
X
. sp.
Porongurup,
X
.
sp.
Limestone
and
X
. sp.
Forests
have been used at
NE
for curatorial purposes and this study
.
Etymology
The specific epithet honours the work of botanist Paul Graham Wilson (1928–), of the Western Australian Herbarium (
PERTH
), who has contributed greatly to Australian daisy taxonomy.
Selected specimens examined
WESTERN AUSTRALIA:
Darling
:
Stirling Range National Park
, summit of
Bluff Knoll
,
16 Dec. 2018
,
T.L. Collins
1157
(
CANB
!, K!,
NE
!,
PERTH
!,
US
!);
Stirling Range National Park
, summit of Toolbrunup,
16 Dec. 2018
,
T.L. Collins
1158
(
CANB
!,
NE
!,
PERTH
!); Walpole–
Nornalup National Park
, Conspicuous Cliffs,
18 Dec. 2018
,
T.L. Collins
1161
(
CANB
!, K!,
NE
!,
NSW
!,
PERTH
!,
US
!); Walpole–
Nornalup National Park
, Delta Road,
18 Dec. 2018
,
T.L. Collins
1162
(
CANB
!,
NE
!,
PERTH
!); Collier Peak, Porongurup Range,
20 Nov. 1987
,
G.J. Keighery
8722
(
PERTH
!)
;
Yallerungup Peak
,
Porongurup Range
,
15 Dec. 1986
,
G.J. Keighery
8419
(
PERTH
!)
;
Mount Many Peaks
,
4 Oct. 1994
,
S. Barrett
24
(
PERTH
!)
.