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 interiore
Paul G.Wilson
,
Nuytsia
28: 19 (2017)
Type
:
4 miles
[
~
6.4 km
] east of
Acacia
Well, Undoolya
,
Northern Territory
,
9 Nov. 1954
,
G. Chippendale
450
(holo:
AD 95805047
; iso:
BRI
,
CANB 37993
, DNA A0000450,
NSW 518728
,
PERTH 00423815
*)
.
Erect, annual (never biennial), taprooted herb.
Stems
and
branches
hispid with septate trichomes, or glabrescent, and with glands; internode length
15–20 mm
.
Basal leaf rosette
often present at flowering, or absent (will flower with loose basal rosette in drier seasons).
Basal leaves
obovate to spathulate,
70–110 mm
long and
15–35 mm
wide, base auriculate and attenuate, apex apiculate; abaxial indumentum with glands, midvein indumentum pilose with septate trichomes; adaxial indumentum with scattered septate trichomes.
Cauline leaves
spathulate to obovate,
50–200 mm
long and
10–30 mm
wide, leaf base attenuate and auriculate, margin hirsute with septate trichomes, apex mucronate;
abaxial indumentum
with glands, midvein indumentum hispid with septate trichomes, and with glands;
adaxial indumentum
hirsute with septate trichomes, and with glands.
Foliaceous bracts subtending capitula
~
2–4 mm
long or absent, margin fimbriate or hispid.
Capitula
25–40 mm
wide, terminal, in panicles.
Outer phyllaries
broad-ovate, straw-coloured, basal margin fimbriate, abaxial surface smooth, apex obtuse or apiculate.
Medial phyllaries
ovate to narrow ovate, abaxially yellow, apex cuspidate.
Stylar appendages
narrowly triangular or rounded.
Cypsela
~
3.5 mm
long and
0.9 mm
wide, cross-section squarish or circular; pericarp grey–brown, idioblasts present.
Pappus
deciduous, ~
10–11 mm
long.
Fig. 29. Distribution of
Xerochrysum hispidum
.
Fig. 30. Isotype of
Xerochrysum hispidum
(I.R.Telford 13546, J.J.Bruhl & S.Dema
, NE 109359).
Distribution
Occurs sporadically following winter rainfall over a broad area in central
Australia
, including the Finke, MacDonnell Ranges, Great Sandy Desert, and Central Ranges bioregions, with a disjunct distribution in the
Pilbara Bioregion
(
Fig. 31
).
Phenology
Recorded flowering July–September and fruiting September– December.
Habitat
Acacia
shrublands on red–orange sandy loam and gravelly loam soils.
Notes
A specimen from Balladonia,
Western Australia
(
B.L.Turner 5251
,
MEL
602769!) is noteworthy in that it has cobwebby trichomes below the capitulum (
v.
short
, stiff, septate trichomes) and immediately noticeable, much shorter (
15–30 mm
long) obovate cauline leaves (
v.
spathulate
to obovate cauline leaves,
50–200 mm
long). The area in which this collection was made is markedly disjunct from all other populations of
X. interiore
and other species of
Xerochrysum
in
Western Australia
Conservation status
Occurs over a wide geographical area, including in several conservation reserves and is not considered to be rare or threatened. We recommend a status of ‘
Least Concern
’ (
IUCN 2019
).
Selected specimens examined
NORTHERN TERRITORY
:
MacDonnell
:
1.4 km
N of Erldunda Roadhouse
, ~
50 m
E of
Stuart Highway
,
25 Sep. 2016
,
J.J. Bruhl
3446
(
NE
!,
NT
!);
Alice Springs
,
500 m
NE
of the end of
Baldissera Drive
,
19 Oct. 2014
,
T.L. Collins
713
(
NT
!,
NE
!);
S of Alice Springs
,
17 km
along
Maryvale Road
,
2 Jul. 2014
,
T.L. Collins
706
(
NT
!,
NE
!)
.
SOUTH AUSTRALIA
: unincorporated:
De Rose Hill Station
~
9 km
NE
of Homestead
,
31 Aug. 1989
,
H.P. Vonow
1288
(
AD
!)
.
WESTERN AUSTRALIA
:
Fortescue
:
Wanna Munna Road
,
Pilbara
,
22 Aug. 2018
,
T.L. Collins
1073 &
J.J. Bruhl
(
CANB
!,
NE
!,
NT
!,
PERTH
!)
.
Ngaanyatjarraku
: ~
49 km
N of Mount Fanny on Giles
–
Mount Davies
road,
11 May 1977
,
M. Lazarides
8341
(
CANB
,
NSW
,
PERTH
!)
.
Dundas
:
87.7 km
E of Norseman on Eyre Highway
,
16 Aug. 1995
,
R.J. Cranfield
10058
(
PERTH
!)
.