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Lowrie & Conran • The Drosera omissa/D. nitidula complex
TA XON 56 (2) • May 2007: 533–544
533
INTRODUCTION
The members of the Drosera omissa Diels/D. nitidula
Planch. complex are all endemic to south-west Western
Australia and belong to subgen. Bryastrum (Planch.)
Schlauer sect. Lamprolepis Planch. (Schlauer, 1996) [ =
subgen. Rorella (DC.) Diels p.p. nom. superfl. sensu Mar-
chant & al., 1982]. The members of this subgenus are
known commonly as Pygmy Sundews or Pygmy Drosera
and currently represent over 60 species, infrataxa, natural
hybrids and/or distinctive unnamed morphs, all of which
are native to SW Western Australia and only one of which,
D. pygmaea DC., extends to E Australia and New Zealand
(Lowrie, 1989, 1998).
The D. omissa/D. nitidula complex, as presently
recognised, represents some six entities which have been
given several different names, depending on taxon rank
concepts and problems in the correct application of names.
Following the nomenclature of Paczkowska & Chapman
(2000), the taxa under consideration were D. nitidula subsp.
omissa (Diels) N.G. Marchant & Lowrie, D. ericksoniae
N.G. Marchant & Lowrie, D. nitidula subsp. nitidula, D.
nitidula subsp. allantostigma N.G. Marchant & Lowrie,
D. nitidula subsp. leucostigma N.G. Marchant & Lowrie,
and the taxon listed in Lowrie (1989) as D. nitidula subsp.
omissa (Diels) Lowrie nom. illeg. non Diels (an unnamed
taxon listed as ‘var. ?’ in Schlauer, 1996).
Species and infrataxon concepts in the genus are the
subject of ongoing research and discussion. Marchant &
Lowrie (1992) regarded most pygmy sundew variants be-
low the species level to be sufficiently different to warrant
subspecific rank. In contrast, Schlauer (1996) adopted a
typological approach of equivalent degree of difference
within a rank, similar to the phenetics-based proposal for
taxon consistency in the genus of Goodall & Marchant
(1996). Schlauer defined subspecies as geographically
allopatric, reducing taxa to varietal rank where their
overall distributions overlapped, and also adopted a
more conservative Drosera species concept, reducing
taxa described by Debbert (1991), Lowrie & Carlquist
(1992) and Marchant & Lowrie (1992) to subspecific or
varietal status.
Nevertheless, as many of these apparently sympatric
taxa are ecologically allopatric, and there is no evidence
of intergradation across their ranges, the trend in Australia
has been to either maintain their original rank designa-
tions (e.g., Paczkowska & Chapman, 2000) or, to elevate
distinctive taxa to specific rank on the grounds that they
are allopatric over a wide range, but both ecologically
isolated and without evidence of intergradation which
might otherwise indicate gene flow between them.
Our study aimed to determine the correct identity of
the taxon originally described by Diels (1906) as D. om-
issa and the relationships between the remaining entities
in the complex, especially the unnamed taxon previously
confused with D. omissa.
MATERIALS AND METHODS
Field studies of south-west WA populations of the
Drosera omissa/D. nitidula complex were variously un-
dertaken by the authors between 1988 and 2003. In addi-
tion, herbarium specimens lodged at PERTH and MEL
A revision of the Drosera omissa/D. nitidula complex (Droseraceae) from
south-west Western Australia
Allen Lowrie
1
& John G. Conran
2
1
6 Glenn Place, Duncraig, W.A. 6023, Australia
2
Centre for Evolutionary Biology and Biodiversity, Environmental Biology, School of Earth and
Environmental Sciences, Darling Building DP418, The University of Adelaide, S.A. 5005, Australia.
john.conran@adelaide.edu.au (author for correspondence)
The Drosera omissa/D. nitidula complex is revised. Drosera omissa is reinstated and found to be conspecific
with D. ericksoniae, which is reduced to synonymy. The taxon corresponding to the type of D. nitidula is deter-
mined and D. allantostigma and D. leucostigma are elevated from subspecific to specific rank. Drosera patens
(known previously as D. nitidula subsp. ‘omissa’ and D. nitidula ‘var. ?’) is described as a new species. All five
species are compared morphologically, described and illustrated. Cytological investigation found all species to
have chromosome numbers of n = 14 and 2n = 28, suggesting a base number of x = 7 for the complex.
KEYWORDS: cytology, Drosera allantostigma, D. leucostigma, D. nitidula, D. omissa, D. patens,
morphology, seeds, taxonomy
534
TA XON 56 (2) • May 2007: 533–544
Lowrie & Conran • The Drosera omissa/D. nitidula complex
were examined, as were living and herbarium collections
in ADU, Herbarium Lowrianum (hl), and type material
and associated collections held at K and B. Wild-collected
gemmae of all known populations of the taxa, and seeds
from as many populations as possible were examined
under SEM and stereo dissecting microscope.
Chromosome counts were made from actively
growing root and shoot tips of either field collected or
cultivated plants, as well as meiotic counts from buds of
taxa where available. The mitotic tissues were pretreated
in aqueous 0.002% 8-hydroxy-quinoline for three hours
at 20°C. All tissues were fixed overnight in Dyer’s (1963)
modified Carnoy’s fixative (10 : 2 : 2 : 1 Ethanol : Acetic
Acid : Chloroform : Formalin), rinsed and stored at –18°C
in 70% Ethanol. The samples were then stained in Snow’s
(1963) acid-alcoholic carmine for 24–48 hrs. at 60°C,
rinsed and squashed in 45% Acetic Acid. The coverslips
were removed by the freeze method of Conger & Fairch-
ild (1953), but using a –80°C freezer, air-dried overnight
and mounted in Histomount
®
. Counts were made under
oil-immersion using a Zeiss photomicroscope at 2,500
magnification.
Morphological descriptions were based on fresh,
dried and spirit material.
RESULTS
The differences in adult morphology, gemma struc-
ture (Fig. 1), breeding system and cytology between
the taxa are detailed in Table 1. This shows that they
all differ from each other to about the same degree as
most other generally accepted species of pygmy Dro-
sera, and combined with their geographic and/or local
ecological isolation supports the recognition of these taxa
as separate, albeit related species. Morphology within
populations was generally uniform, possibly reflecting
the largely self-compatible breeding systems seen in
most of the species in the complex, although it could
also reflect the effects of clonal reproduction in pygmy
Drosera generally (Karlsson & Pate, 1992; Chen & al.,
1997; Darnowski & al., 2003).
Comparisons of the type material for D. omissa also
found it to be identical to D. ericksoniae, and the con-
sequent reduction of the latter into synonymy and the
recognition of three new species within the D. nitidula
complex, brings the total number of currently described
Pygmy Sundew species to 47.
Comparison of the seeds of populations of the differ-
ent taxa revealed that there were conspicuous and consist-
Fig. 1. SEM micrographs of gemmae in the Drosera omissa/D. nitidula complex showing abaxial (A, C, E, G, I) and adaxial
surfaces (B, D, F, H, J). A–B, D. allantostigma, Lowrie 2455 (PERTH); C–D, D. leucostigma, Lowrie s.n., N of Cataby 8 Dec
1983 (PERTH); E–F, D. nitidula, Lowrie 502 (PERTH); G–H, D. omissa, Lowrie s.n., Kalbarri Nat. Pk., 14 June 1984 (PERTH);
I–J, D. patens, Lowrie 2033 (PERTH). Scale bars = 100 µm.
535
Lowrie & Conran • The Drosera omissa/D. nitidula complex
TA XON 56 (2) • May 2007: 533–544
Table 1. Diagnostic morphological characters of the new Drosera taxa.
Character D. allantostigma D. leucostigma D. nitidula D. omissa D. patens
Rosette size (mm) 10–20 10–20 10–15 15–30 18–25
Stem length (mm) Up to 8 Up to 5 Up to 5 2–5 2–5
Petiole shape ± linear, tapering ± linear, tapering
slightly upwards
from base
± linear, tapering
or slightly dilated
in the middle
± linear, tapering ± linear, tapering
or slightly dilated
in the middle
Petiole section Strongly de-
pressed-ovate
Strongly de-
pressed-ovate
Strongly de-
pressed-ovate
Strongly de-
pressed-triangular
Strongly de-
pressed-ovate
Petiole size (mm) 3.5–6.0 × 0.75–0.7,
tapering to 0.3–0.4
4.5–6.0 × 0.4–0.5,
tapering to 0.3–0.4
4.0–5.5 × 0.4–0.5
tapering to 0.2–0.3
4.0–6.0 × 0.4–0.8,
tapering to 0.3–0.6
5.0–8.0 × 0.5–0.7,
tapering to 0.2–0.5
Petiole microglands Numerous Numerous Numerous Numerous Numerous
Lamina shape ± elliptic to ob-
ovate
± elliptic to obo-
vate
Orbicular, nar-
rowly obovate
and ± elliptic to
obovate
Obovate Narrow ovate to ±
elliptic or obovate
Lamina size (mm) 1.5–2.5 × 1.0–2.0 2.5–3.0 × 1.5–2.0 1.5–2.5 × 1.0–1.5 3.5–4.0 × 1.5–2.0 1.8–3.0 × 1.3–2.5
Leaf colour Basally green, api-
cally reddish
Basally green, api-
cally deep red
Basally green, api-
cally deep red
Basally green,
apically bronze,
and/or all bronze
or reddish
Basally green, api-
cally light red
Stipular bud shape Broadly ovoid,
fimbriate
Broadly ovoid,
fimbriate
Broadly ovoid,
fimbriate
Ovoid, fimbriate Ovoid, fimbriate
Stipular bud size (mm)
4.0–7.0 × 3.5–4.0 ∅ 3.5–4.5 × 3.5–4.5 ∅ 3.0–4.5 × 3.0–4.0 ∅ 3.0–3.5 × 2.5–3.0 ∅ 5.0–6.5 × 5.0–5.5 ∅
Stipule size (mm)
3.5–4.5 × 3.0–4.0 ∅ 3.5–4.0 × 3.0–4.0 ∅ 3.0–3.5 × 3.0–4.0 ∅ 4.0–5.0 × 3.0–4.0 ∅ 4.0–4.5 × 3.0–4.0 ∅
Stipule shape 3-lobed; central
lobe with 3 seg-
ments, each with
2–3 laciniae;
lateral lobe inner
margins with 4
laciniae
3-lobed; cen-
tral lobe with 3
segments, each
with 1–2 laciniae;
lateral lobe inner
margins with 5–6
laciniae
3-lobed; cen-
tral lobe with 3
segments, each
with 1–2 laciniae;
lateral lobe inner
margins with 3–4
laciniae
3-lobed; central
lobe with 3 seg-
ments, central one
with 3 laciniae,
lateral ones with
2 laciniae; lateral
lobe inner margins
with 4–5 laciniae
3-lobed; central
lobe with 3 seg-
ments, central one
with 1–2 laciniae,
lateral ones with
2–3 laciniae;
lateral lobe inner
margins with 4
laciniae
Scape height, including
inflorescence (mm)
40–80 25–30 20–25 25–45 25–50
Scape length (mm) 30–55 15–20 10–15 20–25 10–20
Scape/infl. indumentum Sparsely glandular Moderately glan-
dular
Moderately glan-
dular
Sparsely glandular Moderately glan-
dular
Pedicel length (mm) 5.0–6.0 at anthesis
to 10.0 in fruit
2.0–3.0 at anthesis
to 5.0 in fruit
2.0–3.0 at anthesis
to 5.0 in fruit
2.5–3.0 at anthesis,
not elongating in
fruit
1.5–2.0 at anthesis
to 6.0 in fruit
Bracteoles Subulate, glan-
dular
Filiform to nar-
row-subulate,
glandular
Narrow-subulate,
glandular
Subulate to fili-
form, glandular
Subulate, glan-
dular
Number of flowers 12–20 4–12 4–12 6–12 6–14
Sepal shape at anthesis Ovate Ovate Narrowly ovate Narrowly ovate to
ovate
Ovate
Sepal size at anthesis (mm)
1.7–2.0 × 0.8–1.0 1.5–2.0 × 0.7–1.0 1.5–2.0 × 0.7–1.0 2.0–2.3 × 0.8–1.3 1.5–2.0 × 0.6–0.8
Petal shape Cuneate-obovate Cuneate-obovate Cuneate-obovate Obovate to cuneate Cuneate
Petal size (mm) 3.5–4.5 × 2.5–2.8 2.2–2.5 × 1.6–1.8 2.6–3.3 × 2.0–2.3 4.0–6.0 × 3.5–6.5 3.0–3.8 × 1.8–2.8
536
TA XON 56 (2) • May 2007: 533–544
Lowrie & Conran • The Drosera omissa/D. nitidula complex
ent differences between them (Fig. 2). Seeds are ellipsoid
in D. allantostigma, D. nitidula, ovoid in D. leucostigma
and D. patens, and broadly ovoid in D. omissa. The four
members of the nitidula complex s.str. also show a shortly
exserted projection at the micropylar end which is absent
in D. omissa.
Results from cytological investigations of the com-
plex are also presented (Fig. 3), with all species examined
having numbers of n = 14 and 2n = 28 suggesting a base
number of x = 7. There are 8 medium (c. 1.7 μm) and 20
small (c. 0.7 μm) chromosomes in the mitotic stage, and
they are more or less similar across all species, ranging
from 2.0–0.6 μm in length (mitotic counts). This agrees
with previous reports for D. patens by Kondo & Oliver
(1979) and Kondo & Lavarack (1984) as D. nitidula from
Cannington, actually Canning Vale (see Rose, 1977), and
by Chen & al. (1997) as D. nitidula subsp. omissa sensu
Lowrie (1989).
Table 1. Continued.
Character D. allantostigma D. leucostigma D. nitidula D. omissa D. patens
Petal colour White; midvein
pinkish
White; midvein
grey to reddish
White; midvein
grey
Pink to white;
base green;
midvein grey
White; midvein
basally reddish
Anther colour White Yellow Red Pale yellow Red
Pollen colour Orange Orange Yellow Yellow Yellow
Ovary shape Obovoid Subglobose Obovoid Broadly obovoid Obovoid
Ovary size (mm) 0.8 long, 0.9 ∅ 0.6 long, 0.7 ∅ 0.8 long , 1.0 ∅ 0.7 long, 0.8–0.9 ∅ 1.2 long, 0.7 ∅
Stigma number 3–4 3–4 3–4 (mostly 3) 3–4 3–4 (mostly 3)
Stigma shape Allantoid Reniform Reniform Disc-like, peltate Reniform
Stigma colour Maroon-red White Light red Light green to
yellow
Dark red
Fruit disposition Pendulous Semi-erect to
horizontal
Semi-erect to
horizontal
Semi-erect Semi-erect to
horizontal
Sepal disposition in fruit Erect; involute Erect; involute Erect to apically
clasping; flat-
curved
Erect; flat-curved Patent; involute
Sepal length in fruit (mm) 2.0–2.5 2.0–2.5 3.0–3.5 2.0–2.5 2.5–3.0
Gemma shape Suborbicular,
basally 2-lobed,
apically depressed
with 1 gland
Broadly ovate,
basally 2-lobed,
apically depressed
with up to 3 glands
Broadly ovate,
basally 2-lobed, 1
apical gland
Broadly ovate,
basally 1-lobed,
apically depressed
with 1 gland
Ovate, apex acute,
basally 3-lobed, 1
apical gland
Gemma section Basally dilated
ad- and abaxially
almost to the apex
Medially dilated
ad- and abaxially,
tapering towards
the base and apex
Basally dilated ad-
and abaxially in
lower two thirds,
tapering apically
Medially broadly
dilated longitu-
dinally ad- and
abaxially
Basally narrow for
two thirds, taper-
ing apically
Gemma size (mm) 1.0 × 0.9, 0.5 thick 1.0 × 0.7, 0.4 thick 1.4 × 1.0, 0.4 thick 1.0 × 0.9, 0.6 thick 1.5 × 0.9, 0.2 thick
Seed shape Ellipsoid Ellipsoid Ellipsoid Broadly ovoid Ovoid
Seed surface sculpturing Anticlinal walls
obscurely sinuous;
periclinal walls
irregularly rough-
ened, depressed
Anticlinal walls
obscurely sinuous;
periclinal walls
smooth, not de-
pressed
Anticlinal walls
sinuous; periclinal
walls smooth,
depressed
Anticlinal walls
sinuous, minutely
crenulate; pericli-
nal walls smooth,
depressed
Anticlinal walls
obscurely sinuous;
periclinal walls
irregularly rough-
ened, depressed
Seed micropylar end Shortly exserted Shortly exserted Shortly exserted Barely exserted Shortly exserted
Breeding system Not self compat-
ible
Self compatible Self compatible Self compatible Self compatible
Chromosome number
n = 14; 2n = 28
(current study)
n = 14; 2n = 28
(current study)
n = 14; 2n = 28
(current study and
S. James, unpubl.
data)
n = 14; 2n = 28
(current study and
S. James, unpubl.
data)
n = 14; 2n = 28
(current study and
S. James, unpubl.
data)
537
Lowrie & Conran • The Drosera omissa/D. nitidula complex
TA XON 56 (2) • May 2007: 533–544
TAXONOMY
Modifed part key from Lowrie (1998, pp. 29–30)
showing application of new names:
22. Stigmas reniform, allantoid, clavate,
obpyriform or disc-shaped . . . . . . . . . . . . 23
22. Stigmas whip-like or continuous with style . . . 28
23. Stigmas white, light green or yellow . . . . . . . 24
23. Stigmas reddish . . . . . . . . . . . . . . . . . . 26
24. Stigmas reniform, peltate . . . . . . D. leucostigma
24. Stigmas obpyriform or disc-shaped,
peltate . . . . . . . . . . . . . . . . . . . . . . . 25
25. Stigmas obpyriform . . . . . . . . . . . D. mannii
25. Stigmas disc-shaped . . . . . . . . . . . D. omissa
26. Stigmas allantoid . . . . . . . . . D. allantostigma
26. Stigmas reniform . . . . . . . . . . . . . . . . . 27
27. Sepals clasping apically in fruit;
lamina suborbicular . . . . . . . . . . D. nitidula
27. Sepals erect, not clasping apically in
fruit; lamina spathulate . . . . . . . . . . D. patens
Fig. 3. Meiotic chromosomes of the Drosera omissa/D. nitidula complex. A, D. allantostigma, metaphase I, Lowrie 2455
(PERTH); B, D. leucostigma, metaphase I, Lowrie s.n., N of Cataby 8 Dec 1983 (PERTH); C, D. nitidula, anaphase I showing
separating two sets of n = 14, Lowrie 502 (PERTH); D, D. omissa, anaphase I, Lowrie s.n., Kalbarri Nat. Pk., 14 June 1984
(PERTH); E, D. patens, metaphase I, Lowrie 2033 (PERTH). Scale bar = 10 µm.
Fig. 2. SEM micrographs of seeds (A, C, E, G, I) and micropylar ends (B, D, F, H, J) in the Drosera omissa/D. nitidula
complex. A–B, D. allantostigma, Lowrie 2455 (PERTH); C–D, D. leucostigma, Lowrie s.n., N of Cataby 8 Dec 1983 (PERTH);
E–F, D. nitidula, Lowrie 502 (PERTH); G–H, D. omissa, Lowrie s.n., Kalbarri Nat. Pk., 14 June 1984 (PERTH); I–J, D. patens,
Lowrie 2033 (PERTH). Scale bars = 100 µm.
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TA XON 56 (2) • May 2007: 533–544
Lowrie & Conran • The Drosera omissa/D. nitidula complex
Drosera allantostigma (N.G. Marchant & Lowrie) Lowrie
& Conran, comb. nov. Basionym: D. nitidula subsp.
allantostigma N.G. Marchant & Lowrie, Kew Bull.
47: 325. 1992 – Holotype: Western Australia, Brand
Highway, 1.3 km N of Hill River, in loam or sandy
clay soils around the margins of wet depressions
amongst low heath, A. Lowrie 87/056, 7/11/87 [7
November 1987] (PERTH) ≡ D. nitidula var. allan-
tostigma (N.G. Marchant & Lowrie) Schlauer, Carn.
Pl. Newsl. 25: 73. 1996.
A fibrous-rooted perennial herb with leaves semi-
erect (inner younger ones) arranged in a loose open group
of leaves at the top and more or less horizontal (older outer
ones) forming a compact rosette at the base, 10–20 mm
diam., older specimens always positioned above the soil
surface. Stem up to 8 mm long, covered with the remains
of previous seasons’ leafy growth. Active leaves 10–20 per
rosette, often reduced in number towards the end of an-
thesis; petiole ± linear, tapering, 3.5–6.0 mm long, 0.5–0.7
mm wide at the base, 0.3–0.4 mm wide at the lamina, very
depressed ovate in section, c. 0.2 mm thick, covered with
numerous scattered translucent white minute glands on the
adaxial and abaxial surface as well as the margins. Lamina
± elliptic to obovate, 1.5–2.5 mm long, 1–2 mm wide, adax-
ial surface with insect-catching glands positioned around
the margins and smaller glands within, abaxial surface
glandular. Stipular bud broadly ovoid, fimbriate, 4–7 mm
long, 3.5–4.0 mm diam. at the base, somewhat buried in
the many emerging juvenile leaves; stipules 3.5–4.5 mm
long, 3–4 mm wide, 0.5–0.9 m wide at the base, 3-lobed;
central lobe lacerated into 3 segments, each divided into
2–3 laciniae, lateral lobes upper outer margins mostly
entire, sometimes a little serrate, apex and inner margin
divided into 4 laciniae, the innermost lacinia ± equalling
the longest lacinia of the central lobe. Flowering stems 1–2
per basal rosette, 4–8 cm (mostly 5–6 cm) tall, sparsely
covered with translucent-white trichomes with red glan-
dular heads c. 0.05 mm long; scape thread-like; inflores-
cence forming a 12–20-or more-flowered helicoid cyme.
Pedicels 5–6 mm long at anthesis, later up to 10 mm long
and pendulous in fruit, sparsely covered with translucent-
white trichomes with red glandular heads c. 0.01 mm long.
Bracteoles subulate, 0.8–1.0 mm long, c. 0.05 mm wide
at the base, glandular. Sepals (at anthesis) ovate, 1.7–2.0
mm long, 0.8–1.0 mm wide, lowermost margins entire,
upper margins and apex ± irregularly dentate, surface
bearing a few scattered translucent-white trichomes with
red glandular heads c. 0.1 mm long, sepal disposition in
fruit, 2.0–2.5 mm long, erect, not longitudinally involute.
Petals adaxial surface white with a pinkish midvein, abax-
ial surface white with a pinkish midvein, cuneate-obovate,
margins entire, apex entire to ± irregularly crenate, 3.5–
4.5 mm long, 2.5–2.8 mm wide. Stamens 5, 1.0–1.8 mm
long, filaments and anthers white, pollen orange. Ovary
greenish brown, obovoid, c. 0.8 mm long, c. 0.9 mm diam.
Styles 3–4, white, horizontal, terete, c. 0.1 mm diam., c.
0.4 mm long; stigmas maroon-red, horizontal, allantoid
(formed horseshoe-like), 1.0–1.4 mm long, 0.3–0.5 mm
diam., papillose, peltate attachment visible on both sides of
the stigma. Gemmae suborbicular, basally 2-lobed, apically
depressed with 1 gland, c. 1 mm long, c. 0.9 mm wide, c.
0.5 mm thick. Seed ± ellipsoid, apical pole ± emarginate,
0.25–0.3 mm long, 0.18–0.2 mm diam.; funicle c. 0.05 mm
long, c. 0.05 mm diam.; testa dark slate coloured, reticulate.
Chromosome number 2n = 28 fide J.G. Conran, voucher AL
2445 (PERTH, Herbarium Lowrianum ) (Fig. 4).
Selected specimens examined: WESTERN AUS-
TRALIA: Type location north of Hill River, 4 Jan. 2000,
A. Lowrie 2445 (PERTH, MEL).
Known from a few scattered road side locations
between the type location and c. 10 km further north
along the Brand Highway. Grows in loam, silica sand or
peaty sand soils on the margins of winter wet depressions.
Fig. 4. Drosera allantostigma. A, habit; B, lamina; C, petiole
cross section; D, stipule; E, abaxial view of sepal; F, petal;
G, gynoecium; H, styles and stigmas, adaxial view; I, style
and stigma, abaxial view. Source Lowrie 2455 (PERTH).
Scale bars = 1 mm.
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Lowrie & Conran • The Drosera omissa/D. nitidula complex
TA XON 56 (2) • May 2007: 533–544
Flowering occurs in November–December. Rarely fully
dormant unless a prolonged drought occurs. Remains in a
state of slowed growth well into the dry months provided
a little available moisture is still present deeper in the soil
profile of its habitat. DEC Conservation status: Priority
One – Poorly Known Taxa. Due to extensive land clearing
for farmland, D. allantostigma is currently only known
from a few scattered roadside locations between the type
location and c.10 km further north along the Brand High-
way. Drosera allantostigma is distinguished from all other
Pygmy Sundew species with ± reniform, red stigmas by
its: tall scapes; very long pedicels at anthesis; elongating
and pendulous pedicels in fruit; peltate style attachment
visible on both sides of the stigma; and maroon-red, more
or less hippocrepiform stigmas. A hybrid between D. al-
lantostigma and D. omissa occurs at a single site a few
kilometres north of the D. allantostigma type location.
Drosera leucostigma (N.G. Marchant & Lowrie) Lowrie
& Conran, comb. nov. Basionym: D. nitidula subsp.
leucostigma N.G. Marchant & Lowrie, Kew Bull.
47: 326. 1992. – Holotype: Western Australia, Brand
Highway, 14.3 km NW of Cataby, in sandy soils on
the margins of wet depressions, A. Lowrie 87/058,
7/11/87 [7 November 1987] (PERTH) ≡ D. nitidula
var. leucostigma (N.G. Marchant & Lowrie) Schlauer,
Carn. Pl. Newsl. 25: 73. 1996.
A fibrous-rooted perennial herb forming a compact
rosette of leaves, 10–20 mm diam., older specimens al-
ways positioned above the soil surface. Stem up to 5 mm
long, covered with the remains of previous seasons’ leafy
growth. Active leaves 20–35 per rosette, often reduced
in number towards the end of anthesis; petiole ± linear,
tapering slightly upwards from base, 4.5–6.0 mm long,
0.4–0.5 mm wide at the base, 0.3–0.4 mm wide at the
lamina, very depressed ovate in section, c. 0.3 mm thick,
covered with numerous scattered translucent white minute
glands on the adaxial and abaxial surface as well as the
margins. Lamina ± elliptic to obovate, 2.5–3.0 mm long,
1.5–2.0 mm wide, adaxial surface with insect-catching
glands positioned around the margins and smaller glands
within, abaxial surface glandular. Stipular bud broadly
ovoid, fimbriate, 3.5–4.5 mm long, 3.5–4.5 mm diam. at
the base, somewhat buried in the many emerging juvenile
leaves; stipules 3.5–4.0 mm long, 3–4 mm wide, 0.7–0.8
mm wide at the base, 3-lobed; central lobe lacerated into
3 segments, each divided into 1–2 laciniae, lateral lobes
outer margins entire as well as irregularly serrate, apex
and inner margin divided into 5–6 laciniae, the longest
lacinia ± equalling the longest lacinia of the central lobe.
Flowering stems 1–2 per basal rosette, 2.5–3.0 cm (mostly
2.0–2.5 cm) tall, moderately covered with translucent-
white trichomes with red glandular heads c. 0.05 mm long;
scape thread-like; inflorescence forming a 4–12 flowered
helicoid cyme. Pedicels 2–3 mm long at anthesis, later
up to 5 mm long and semi erect and horizontal in fruit,
moderately covered with translucent-white trichomes with
red glandular heads c. 0.05 mm long. Bracteoles filiform
to narrowly subulate, 0.5–1.0 mm long, c. 0.05 mm wide at
the base, glandular. Sepals (at anthesis) ovate, 1.5–2.0 mm
long, 0.7–1.0 mm wide, lowermost margins entire, upper
margins and apex entire or ± irregularly dentate, surface
covered with translucent-white trichomes with red glan-
dular heads c. 0.1 mm long, sepal disposition in fruit,
2.0–2.5 mm long, erect, longitudinally involute. Petals
adaxial surface white with a greyish to reddish midvein,
abaxial surface similar, cuneate-obovate, margins entire,
apex entire to ± irregularly crenate, 2.2–2.5 mm long,
1.6–1.8 mm wide. Stamens 5, 0.5–0.8 mm long, filaments
white, anthers yellow, pollen orange. Ovary pale green,
subglobose, c. 0.6 mm long, c. 0.7 mm diam. Styles 3–4,
white, horizontal, terete, c. 0.1 mm diam., c. 0.2 mm
long; stigmas white, reniform, c. 0.5 mm long, c. 0.3 mm
wide, peltate, papillose. Gemmae broadly ovate, basally
2-lobed, apically depressed and bearing up to 3 glands,
c. 1.0 mm long, c. 0.7 mm wide, c. 0.4 mm thick. Seed ±
ellipsoid, 0.30–0.35 mm long, 0.15–0.2 mm diam. apical
pole bearing a small apical bump; funicle c. 0.03 mm long,
c. 0.05 mm diam.; testa dark slate coloured, reticulate.
Chromosome number 2n = 28 f ide J.G. Conran, voucher
JGC1429 (ADU) (Fig. 5)
Selected specimens examined: Brand Highway, 14.3
km NW of Cataby (type location), 8 Dec. 1983, A. Lowrie
s.n. (PERTH, MEL); 5.2 km W of Mogumber, 29 Jun.
2003, A. Lowrie 2786 (from cultivated material) (PERTH,
MEL); cultivated material from the type location, no ad-
ditional vouchers taken.
Known from the Cataby region and south-east to Mo-
gumber. Grows in sandy soils on the margins of winter
wet depressions.
Flowering occurs from November–January. Rarely
fully dormant unless a prolonged drought occurs. Re-
mains in a state of slowed growth well into the dry months
provided a little available moisture is still present deeper
in the soil profile of its habitat. DEC Conservation sta-
tus: A common species and currently not under threat.
Drosera leucostigma is distinguished by its white ±
reniform stigmas, compact many-leaved rosettes; erect
but not apically patent or clasping sepals in fruit; and its
broadly ovate gemma which are apically depressed and
bear up to 3 apical glands. Drosera leucostigma coexists
with D. closterostigma N.G. Marchant & Lowrie at most
known localities.
Drosera nitidula Planch., Ann. Sci. Nat. (Paris) sér. 3, 9:
285. 1848 – Holotype: “in colonia fluminis Cygnorum
[Swan River Colony, south-west Western Australia];
Drummond in herb. Hook” J. Drummond s.n. (K).
540
TA XON 56 (2) • May 2007: 533–544
Lowrie & Conran • The Drosera omissa/D. nitidula complex
A fibrous-rooted perennial herb forming a compact
rosette of leaves, 10–15 mm diam., older specimens al-
ways positioned above the soil surface. Stem up to 5 mm
long, covered with the remains of previous seasons’ leafy
growth. Active leaves 20–25 per rosette, often reduced
in number towards the end of anthesis; petiole ± linear,
or slightly dilated in middle, 4.0–5.5 mm long, 0.4–0.5
mm wide at the base, 0.2–0.3 mm wide at the lamina,
very depressed ovate in section, c. 0.2 mm thick, cov-
ered with numerous scattered translucent white minute
glands on the adaxial and abaxial surface as well as the
margins. Lamina orbicular, narrowly obovate and ± el-
liptic to obovate, 1.5–2.5 mm long, 1.0–1.5 mm wide,
adaxial surface with insect-catching glands positioned
around the margins and smaller glands within, abaxial
surface glandular. Stipular bud broadly ovoid, fimbriate,
4.5–5.0 mm long, 3–4 mm diam. at the base, somewhat
buried in the many emerging juvenile leaves; stipules
3.0–3.5 mm long, 3–4 mm wide, 0.5–0.7 mm wide at
the base, 3-lobed; central lobe lacerated into 3 segments,
each divided into 1–2 laciniae, lateral lobes outer mar-
gins mostly entire but also sometimes a little irregularly
serrate, apex and inner margin divided into 3–4 lacin-
iae, the longest lacinia ± equalling the longest lacinia of
the central lobe. Flowering stems 1–2 per basal rosette,
2.0–2.5 cm (mostly 2 cm) tall, moderately covered with
translucent-white trichomes with red glandular heads
c. 0.1 mm long; scape thread-like; inflorescence form-
ing a 4–12-flowered helicoid cyme. Pedicels 2–3 mm
long at anthesis, later up to 5 mm long and semi erect
and horizontal in fruit, moderately covered with translu-
cent-white trichomes with red glandular heads c. 0.1 mm
long. Bracteoles narrowly subulate, 1.0–1.5 mm long, c.
0.1 mm wide at the base, glandular. Sepals (at anthesis)
narrowly ovate, 1.5–2.0 mm long, 0.7–1.0 mm wide, low-
ermost margins entire, apex ± irregularly dentate, sur-
face covered with translucent-white trichomes with red
glandular heads c. 0.2 mm long, sepal disposition in fruit,
3.0–3.5 mm long, ± apically clasping, longitudinally in-
volute. Petals adaxial surface white with a greyish mid-
vein, abaxial surface similar, cuneate-obovate, margins
entire, apex entire to ± irregularly crenate, 2.6–3.3 mm
long, 2.0–2.3 mm wide. Stamens 5, 1.3–1.6 mm long,
filaments white, anthers red, pollen yellow. Ovary pale
green, obovoid, c. 0.8 mm long, c. 1 mm diam. Styles
3–4, white, horizontal, terete, c. 0.1 mm diam., c. 0.4
mm long; stigmas light red, reniform, c. 1 mm long, c.
0.5 mm wide, peltate, papillose. Gemmae broadly ovate,
basally 2-lobed, bearing a solitary apical gland, c. 1.4
mm long, c. 1 mm wide, c. 0.4 mm thick. Seed ± ovoid,
0.3–0.35 mm long, 0.19–0.20 mm diam., apical pole ±
bearing a small apical bump; funicle c. 0.03 mm long, c.
0.05 mm diam.; testa shining black coloured, very finely
reticulate. Chromosome number n = 14, fide S.H. James,
voucher A. Lowrie 502 (PERTH, hl ); 2n = 28 f ide J.G.
Conran, voucher JGC1418 (ADU). (Fig. 6)
Selected specimens examined: WESTERN AUS-
TRALIA: Pinjarra industrial estate, 23 Nov. 1986, A.
Lowrie s.n. (PERTH, MEL); Scott River Rd, 25 Nov. 1990,
A. Lowrie 213 (PERTH, MEL); Cape Le Grand Rd, 8 Dec.
1990, A. Lowrie 232 (PERTH, MEL); Swamp heathland
0.3 km E of the junction of Great Northern Highway
and Rutland Rd, 9 Nov. 1991, A. Lowrie 502 (PERTH,
MEL); on Scott River Rd near Brendan’s Ford, just S of
Bridge, E of Augusta, 6 Jan. 1992, A. Lowrie 571 & S.
James (PERTH, MEL); on Cape Le Grand Rd, 2.4 km S
of Merivale Rd, E of Esperance, 29 Nov. 1993, A. Lowrie
853 (PERTH, MEL); Swamp heathland 0.3 km E of the
junction of Great Northern Highway and Rutland Rd, 1
Dec. 1996, A. Lowrie 1632 (PERTH, MEL); Brookton
Highway at headwaters of the Canning River, 28 Dec.
1996, A. Lowrie 1675 (PERTH, MEL).
Fig. 5. Drosera leucostigma. A, habit; B, lamina; C, petiole
cross section; D, stipule; E, abaxial view of sepal; F, petal;
G, gynoecium; H, style and stigma, adaxial view. Source
Lowrie s.n., N of Cataby 8 Dec 1983 (PERTH). Scale bars =
1 mm.
541
Lowrie & Conran • The Drosera omissa/D. nitidula complex
TA XON 56 (2) • May 2007: 533–544
Widespread from Bullsbrook and throughout the
woodlands east of Perth, south to Augusta and east to
Cape Le Grand east of Esperance in coastal and near
coastal areas. Grows in clayey sand soils in and on the
margins of winter wet depressions and swamps.
Flowering occurs from November–January. Rarely
fully dormant unless a prolonged drought occurs.
Remains in a state of slowed growth well into the dry
months provided a little available moisture is still present
deeper in the soil profile of its habitat. DEC Conserva-
tion status: A common species and currently not under
threat.
Drosera nitidula is distinguished from other Pygmy
Sundews with ± reniform red stigmas by its erect, ± ap-
ically clasping sepals in fruit. A natural hybrid between
Drosera nitidula and D. omissa occurs just south of
Pingelly.
Drosera omissa Diels, Pflanzenr. 26: 73. 1906 – Holotype:
“Südwest-Australien: [south-west Western Australia]
o.n.o. (Drummond s.n. – Original der Art!).” J. Drum-
mond s.n. (B, K! Kew negative 15707) ≡ Drosera nit-
idula (Planch.) subsp. omissa (Diels) N.G. Marchant
& Lowrie, Kew Bull. 47: 326. 1992.
= Drosera ericksoniae N.G. Marchant & Lowrie, Kew
Bull. 47: 326. 1992 – Holotype: Western Australia,
Great Southern Highway, 7.5 km S of Pingelly, in
deep white sand around the margins of winter wet
depressions, A. Lowrie 87/073, 9/11/87 [9 Nov. 1987]
(PERTH).
A fibrous-rooted perennial herb with a solitary,
flat, compact leafy rosette, 1.5–3.0 cm (mostly 2.0–2.5
cm) diam., close to the soil surface. Stem 2–5 mm long
with little or no remains of previous seasons’ growth.
Plants commonly carry over to the next growing season
by seed. Active leaves 20–30 per rosette, sometimes
reduced in number towards the end of anthesis; petiole
± linear, tapering, 4–6 mm long, 0.4–0.8 mm wide near
the base, narrowing to 0.3–0.6 mm wide at the lamina,
very depressed triangular in section, c. 0.2 mm thick,
adaxial surface and abaxial surface as well as the margins
covered with scattered short terete-stalked glands. Lamina
obovate (when viewed from abaxial side), 2.2–3.5 mm
long, 1.5–2.0 mm wide, lamina (when viewed from adax-
ial side) with insect-catching glands not only positioned
around the margins with smaller glands within but also
extending well onto the petiole thus making the lamina
spathulate in outline, 3.5–4.0 mm long, 1.5–2.0 mm wide,
moderately cupped, abaxial surface sparsely glandular.
Stipular bud ovoid, fimbriate, 3.0–3.5 mm long, 2.5–3.0
mm diam. at the base; stipules 4–5 mm long, 3–4 mm
wide, 0.4–0.6 mm wide near the base, 3-lobed; central lobe
lacerated into 3 segments, central one shortly divided into
3 laciniae at the apex, lateral ones divided into 2 longer
laciniae at the apex, the innermost one being the longest,
lateral lobes outer margins irregularly serrate, apex and
inner margin divided into 4–5 laciniae, the innermost
lacinia as long as or exceeding the longest laciniae of the
central lobe. Flowering stems 1 to 4 per basal rosette,
2.5–4.5 cm (mostly 3–4 cm) tall (including the scape),
inflorescence forming a 6–12-flowered helicoid cyme,
scape sparsely glandular in the lower section, moderately
increasing in glandular density towards and throughout
the inflorescence; trichomes translucent-white with
red glandular heads, c. 0.05 mm long; pedicels 2.5–3.0
mm long, later of similar length and semi-erect in fruit,
sparsely covered with translucent-white trichomes with
red glandular heads, c. 0.1 mm long, bracteoles subulate
to filiform, 0.7–1.2 mm long, c. 0.1 mm wide at the base,
sparsely glandular. Sepals (at anthesis) narrowly ovate to
ovate, 2–2.3 mm long, 0.8–1.3 mm wide, margins entire,
apex irregularly dentate, abaxial surface covered with
Fig. 6. Drosera nitidula. A, habit; B, lamina; C, petiole cross
section; D, stipule; E, abaxial view of sepal; F, petal; G,
gynoecium; H, style and stigma, abaxial view; I, style and
stigma, adaxial view. Source Lowrie 502 (PERTH). Scale
ba rs = 1 m m.
542
TA XON 56 (2) • May 2007: 533–544
Lowrie & Conran • The Drosera omissa/D. nitidula complex
scattered translucent-white trichomes bearing red or white
glandular heads, c. 0.12 mm long, sepal disposition in
fruit, 2.0–2.5 mm long, erect, not longitudinally involute.
Petals adaxial surface white or light to dark pink, with
a green base and grey veining, abaxial surface similar
except for pink flowered specimens being a paler pink on
their adaxial surface, obovate to cuneate, margins entire,
apex slightly crenate, 4–6 mm long, 3.5–6.5 mm wide.
Stamens 5, 1.3–2.8 mm long, filaments white, anthers
pale yellow, pollen yellow. Ovary pale green, broadly
obovoid, c. 0.7 mm long, 0.8–0.9 mm diam. Style-stigmas
3 to 4, styles white, curving upwards to erect, 1.5–2.1 mm
long, terete, c. 0.1 diam., glabrous, stigma yellow or light
green, disc-like, adaxial surface facing inward, abaxial
surface centrally peltate and positioned on the outside, c.
0.7 diam., c. 0.4 thick, papillose. Gemmae broadly ovate,
basally 1-lobed, apically depressed with 1 gland, c. 1 mm
long, c. 0.9 mm wide, c. 0.6 mm thick. Seed slate grey,
ellipsoid, 0.30–0.35 mm long, 0.18–0.2 mm diam., with
the addition of a small basal funicle, c. 0.25 mm long, c.
0.03 mm diam., surface sculpture reticulate, longitudinal
ridges deep and irregularly undulate, transverse ridges
shallow. Chromosome number n = 14, fide S.H. James,
voucher A. Lowrie 563 (PERTH, hl ); 2n = 28 f ide J.G.
Conran, voucher JGC1353 (ADU). (Fig. 7)
Selected specimens examined: WESTERN AUS-
TRALIA: Kalbarri, 14 Jun. 1984, A. Lowrie s.n. (PERTH,
MEL); Long Creek Rd, NW of Ravensthorpe, 20 Nov.
1989, A. Lowrie s.n. (PERTH, MEL); Kalbarri, 10 Dec.
1991, A. Lowrie 563 (PERTH, MEL).
Widespread from Kalbarri near the west coast and
Ajana to the east, inland of Perth from Northam to Mer-
redin and south east to Ravensthorpe in the wheatbelt
regions. Grows in deep white sands in and on the margins
of winter wet depressions and watersheds in open areas.
Has been found in laterite soils with similar moisture
conditions.
Flowering mostly in October–December but has been
found in flower in June. Rarely fully dormant unless a
prolonged drought occurs. Commonly carries over to the
next growing season by seed. Remains in a state of slowed
growth well into the dry months provided a little available
moisture is still present deeper in the soil profile of its
habitat. DEC Conservation status: A common species and
currently not under threat. Drosera omissa is distinguished
by its distinctive yellow to light green, disc-like, centrally
peltate, extrorse stigmas. Because D. omissa was catego-
rized previously as belonging to the D. nitidula complex
(Diels, 1906), D. ericksoniae, named after the well known
botanical author Rica Erickson, was described by Mar-
chant & Lowrie (1992). Recent research has shown that D.
ericksoniae is comparable with the D. omissa specimens
on the Berlin type sheet annotated by Diels, so D. ericks-
oniae must now be placed in synonymy.
Drosera patens Lowrie & Conran, sp. nov. – Holotype:
Western Australia: north west shores of Lake Gnan-
garra, 31°46′57″ S, 115°52′21″ E, 17 January 1998,
Allen Lowrie 2033 (holotype: PERTH; isotype MEL)
≡ D. nitidula subsp. omissa sensu Lowrie, Carn. Pl.
Aust. 2: 98. 1989. nom. illeg. non Diels (1906).
Caulis brevis. Folia rosulata 18–25 mm lata; petio-
lus 5–8 mm longus, superne paulum angustatus; lamina
anguste-elliptica vel obovatis, 1.8–3.0 × 1.3–2.5 mm.
Gemmae ovata, acute, valde compressa. Pedunculi 1–4,
scapiformes, erectae, 25–50 mm, parce rubro-glandulosi.
Infloriscentia 6–14 flora; pedicelli patentes, sparse glan-
dulosi, 1.5–2.0 mm longi, ad 6.0 mm in fructi; sepala
ovata, 1.5–2.0 mm longa, angusta-involuta patens ad
2.5–3.0 mm in fructescens; petala spathulata vel angu-
sta-obovata, alba, 3.3–3.8 × 1.8–2.8 mm, costa ad basis
rubescens; stamina circa 1.5 mm longa, anthera rubra;
ovarium parvum, styli 3(–4); stigma reniforma, rubra.
Fig. 7. Drosera omissa. A, habit; B, lamina; C, petiole cross
section; D, stipule; E, abaxial view of sepal; F, petal; G,
gynoecium; H, styles and stigmas, lateral views. Source
Lowrie s.n., Kalbarri Nat. Pk., 14 June 1984 (PERTH). Scale
bars = 1 mm.
543
Lowrie & Conran • The Drosera omissa/D. nitidula complex
TA XON 56 (2) • May 2007: 533–544
A fibrous-rooted perennial herb with a solitary, com-
pact leafy rosette, 1.8–2.5 cm diam., close to or above the
soil surface. Stem 2–5 mm long covered with the remains
of previous seasons’ growth. Active leaves 15–30 per ro-
sette, often reduced in number towards the end of anthesis;
petiole ± linear, tapering, or slightly dilated in the middle,
5–8 mm long, 0.5–0.7 mm wide near the base, narrowing
to 0.2–0.5 mm wide at the lamina, very depressed ovate in
section, c. 0.3 mm thick, covered with numerous scattered
translucent white minute glands on the adaxial and abaxial
surface as well as the margins. Lamina narrowly obovate,
obovate and ± elliptic (when viewed from abaxial side),
1.8–3.0 mm long, 1.3–2.5 mm wide, lamina (when viewed
from adaxial side) with insect-catching glands not only
positioned around the margins and with smaller glands
within but also extending glands well onto the petiole
thus making the lamina spathulate in outline, 3.3–4.5 mm
long, 1.3–2.5 mm wide, moderately cupped, abaxial sur-
face glandular. Stipular bud ovoid, fimbriate, somewhat
buried in the many emerging juvenile leaves, 5.0–6.5 mm
long, 5–5.5 mm diam. at the base; stipules 4.0–4.5 mm
long, 3–4 mm wide, 0.4–0.6 mm wide near the base, 3-
lobed; central lobe lacerated into 3 segments, central one
divided into 1–2 laciniae at the apex, lateral ones divided
into 2–3 laciniae at the apex, lateral lobes outer margins
entire, apex and inner margin divided into 4 laciniae, the
innermost lacinia ± equal to the longest lacinia of the
central lobe. Flowering stems 1 to 4 per basal rosette,
2.5–5.0 cm (mostly 2.5–3.5 cm) tall (including the scape)
often branched, inflorescence forming a 6–14-flowered
helicoid cyme, glandular in the lower section, moderately
increasing in glandular density towards and throughout
the inflorescence; trichomes translucent-white with red
glandular heads, c. 0.05 mm long; pedicels 1.5–2.0 mm
long at anthesis, later up to 6 mm long, semi-erect and
horizontal in fruit, moderately covered with translucent-
white trichomes with red glandular heads, c. 0.15 mm long;
bracteoles subulate, 0.5–1.0 mm long, c. 0.1 mm wide at
the base, sparsely glandular; additionally incompletely
formed stipules similar to those of the stipular bud often
develop along side the bracteoles at scattered locations
throughout the inflorescence. Sepals ovate, 1.5–2.0 mm
long, 0.6–0.8 mm wide at anthesis, margins entire, apex
± irregularly dentate, abaxial surface covered with a few
scattered translucent-white trichomes with red glandular
heads, c. 0.05 mm long, sepal disposition in fruit, 2.5–3.0
mm long, patent, longitudinally involute. Petals white
with reddish basal mid-vein, abaxial surface similar,
cuneate, margins entire, apex slightly crenate, 3.0–3.8
mm long, 1.8–2.8 mm wide. Stamens 5, 1.0–1.2 mm long,
filaments white, anthers red, pollen yellow. Ovary pale
green, obovoid, c. 1.2 mm long, c. 0.7 mm diam. Styles
3–4, white, semi-erect, terete, c. 0.1 mm diam., c. 0.5
mm long; stigmas dark red, reniform, c. 1 mm long, c.
0.5 mm wide, peltate, papillose. Gemmae ovate, acute at
the apex, basally 3-lobed, bearing a solitary apical gland,
c. 1.5 mm long, c. 0.9 mm wide, c. 0.2 mm thick. Seed ±
ovoid, 0.27–0.32 mm long, 0.19–0.2 mm diam. apical pole
bearing a small apical bump; funicle c. 0.02 mm long, c.
0.05 mm diam.; testa shining black coloured, reticulate.
Chromosome number n = 14, fide S.H. James, voucher
AL520 (PERTH, hl ); 2n = 28 f ide J.G. Con ra n, voucher
JGC1411 (ADU). (Fig. 8)
Selected specimens examined. WESTERN AUS-
TRALIA: Pinjar Rd, Wanneroo, 19 Nov. 1991, A. Lowrie
520, (PERTH, MEL); Lake Gnangarra, 31 Mar. 1992, A.
Lowrie 586, (PERTH, MEL); Marshall Rd, Beechboro
(no vouchers taken); southern shores of Lake Jandabup,
Wanneroo (no vouchers taken).
Currently known from four locations spread over a
21.25 km distance in the Perth metropolitan area between
Wanneroo and Beechboro with Lake Gnangarra and Lake
Jandabup locations between. Previously also reported as
Fig. 8. Drosera patens. A, habit; B, lamina; C, petiole cross
section; D, stipule; E, abaxial view of sepal; F, petal; G, gy-
noecium; H, style and stigma, adaxial view. Source Lowrie
2033 (PERTH). Scale bars = 1 mm.
544
TA XON 56 (2) • May 2007: 533–544
Lowrie & Conran • The Drosera omissa/D. nitidula complex
a giant form of D. nitidula from the Canning Vale area
c. 15 km S of Perth (Rose, 1977), but now extinct there
due to land clearance and development. Grows on the
margins of swamps, lakes and winter wet depressions in
sandy soils.
Flowering occurs from December–February. Rarely
fully dormant, remains in a state of slowed growth in
the dry months. Can form a dormant stipular bud under
drought conditions, however, few plants survive through
to the following wet season. DEC Conservation status: A
common species and currently not under threat. Drosera
patens is distinguished from its closest relative D. nitidula
by its larger basal rosette, involute, patent-spreading sepals
in fruit; and ovate, acute, strongly compressed gemmae.
Drosera patens grows in association with D. pulchella
Lehm. at all known locations and hybrids between them
occur at three of these sites.
ACKNOWLEDGEMENTS
We would like to thank the directors of PERTH, MEL,
K and B for access to specimens, as well as DEC WA for
permission to collect from lands under their control. Roberta
Cowan A.B.L.O in 2003 and Alex George, Honorary Research
Associate at the Royal Botanic Gardens Kew are thanked for
providing digital images of Drosera type collections housed
at K, as well as CGE, BM, MPU, and S. The School of Earth
and Environmental Sciences, The University of Adelaide is
thanked for provision of facilities to undertake part of this re-
search. The work done by the late Prof. Sid James (Botany Dept,
The University of Western Australia) on meiotic chromosome
counts for some taxa is gratefully acknowledged. This work
was undertaken as part of an ongoing study into the evolution
of the Pygmy Sundews and funded by the National Geographic
Society, Grant #7242-02.
LITERATURE CITED
Chen, L., James, S.H. & Stace, H.M. 1997. Self-incompat-
ibility, seed abortion and clonality in the breeding systems
of several Western Australian Drosera species (Drosera-
ceae). Austral. J. Bot. 45: 191–201.
Conger, A.D. & Fairchild, L.M. 1953. A quick-freeze method
for making smear slides permanent. Stain Technol. 28:
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