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 berarngutta
T.L.Collins & I.Telford
,
sp. nov.
Type
:
AUSTRALIA
:
New South Wales
:
Northern Tablelands
:
New England National Park
,
Eagles Nest Lookout
, below
Point Lookout
,
5 Feb. 2005
,
I.R. Telford
12830 &
L.M. Copeland
, (holo:
NSW
!; iso:
BRI
!,
MEL
!,
NE 83736
!,
PERTH
!)
.
Xerochrysum
sp.
Point Lookout (I.R.Telford 12830)
NE
Herbarium, CHAH,
Austral. Pl. Census
(2020) [accessed
20 February 2020
].
[
Xerochrysum bracteatum auct
. non
(Vent.) Tzvelev: N.N. Tzvelev,
Novosti Sist. Vyssh. Rast.
27: 151 (1990),
p.p.
, populations on the high escarpment cliffs at Point Lookout, New
England
National Park, New South Wales only].
Diagnosis
Distinguished from
X. bracteatum sens
. str.
by a perennial life form (annual or biennial in
X. bracteatum
), abaxial leaf surface pilose with septate and glandular trichomes and glands (only with glands in
X. bracteatum
), cuspidate to apiculate phyllary apices (obtuse in
X. bracteatum
), and foliaceous bracts subtending capitula
10–20 mm
long (
8–10 mm
in
X. bracteatum
); and from all other species in the genus by a long, thick rhizome, a densely pilose leaf indumentum of septate trichomes, and stipitate glands both abaxially and adaxially.
Decumbent, rhizomatous, perennial herb.
Stems
and
branches
with glands and villous with septate trichomes, internode length
40–55 mm
.
Basal leaf rosette
absent at flowering.
Basal leaves
spathulate,
70–200 mm
long and
15–30 mm
wide, base amplexicaul, margin villous with septate trichomes, apex obtuse and mucronate; abaxial indumentum densely pilose with septate trichomes and with glands, midvein indumentum villous with septate trichomes; adaxial indumentum densely pilose with septate trichomes. Radical leaves arising from a rhizome.
Cauline leaves
oblanceolate to obovate,
40–150 mm
long and
4–30 mm
wide, leaf base attenuate, margin villous with septate trichomes, apex apiculate and mucronate;
abaxial indumentum
densely pilose with septate trichomes and sessile glands, midvein indumentum villous with septate trichomes;
adaxial indumentum
hirsute to densely pilose with septate trichomes, and sessile glands.
Foliaceous bracts subtending capitula
10–20 mm
long, margin villous.
Capitula
40–60 mm
wide, terminal, in panicles or solitary.
Outer phyllaries
broad-ovate, brown or straw-coloured, basal margin fimbriate, apex apiculate, abaxial surface smooth.
Medial phyllaries
ovate to lanceolate, abaxially orange or yellow, apex cuspidate to apiculate.
Stylar appendages
narrowly triangular to ovate.
Cypsela
oblong, ~
2.7 mm
long and
0.9 mm
wide, cross-section squarish or circular; pericarp straw- or brass-coloured, idioblasts present.
Pappus
deciduous, ~
7 mm
long.
Fig. 18. Distribution of
Xerochrysum berarngutta
.
Distribution
Endemic to the high-altitude escarpment on the eastern edge of the New
England
Tablelands Bioregion, where it is known only from the vicinity of Point Lookout, ~
70 km
east of Armidale, New South Wales (
Fig. 18
).
Phenology
Recorded flowering from February–April (
Fig. 19
). Latestage infructescence containing small numbers of cypselae collected in April.
Habitat
Occurring in small openings in the canopy at ~1400-m altitude, growing in humic sediments on and between basalt boulders, on steep slopes and broken cliffs. Associated with
Acacia melanoxylon
,
Banksia integrifolia
subsp.
monticola
,
Eucalyptus pauciflora
,
Lomatia fraseri
,
Cassinia telfordii
,
Lomandra longifolia
,
Solanum
and
Plectranthus
.
150°0
̍
0
̎
E
150°0
̍
0
̎
E
Other associated species include the localised cliff-line endemics
Coronidium elatum
subsp.
minus
,
Gingidia rupicola
,
Gaultheria viridicarpa
and
Wahlenbergia telfordii
.
Conservation status
Only known from effectively one population in the New
England
National Park, New South Wales, where 17 plants were recorded scattered along ~
170 m
of escarpment in 2017. On the basis of only one known extant population of less than 50 individuals, we suggest a ‘
Critically Endangered
’ status is appropriate under the
IUCN (2019)
, fulfilling Criteria C2 and D.
Etymology
The species epithet is the traditional name of the
type
locality, a place considered sacred to traditional owners (Steven Ahoy, pers. comm., 2020), as a noun in apposition (
ICN
Art. 23.5, Shenzhen Code,
Turland
et al
. 2018
)
.
Selected specimens examined
NEW SOUTH WALES
:
Northern Tablelands
:
New England National Park
,
Point Lookout
,
12 Apr. 2017
,
T.L. Collins
958 &
J.J. Bruhl
(
BRI
!,
NE
!,
NSW
!);
New England National Park
, Eagles Nest Lookout,
11 Mar. 2006
,
G.P. Duley
69,
J.J. Bruhl
&
I.R. Telford
(
NE
!)
.