Elionurus purpureus E.J.Thomps. (Panicoideae: Andropogoneae: Tripsacinae), a new species for Queensland: circumscription and breeding system

2017·11.5 MB·English

by  E J Thompson

Elionurus purpureus E.J.Thomps. (Panicoideae:
Andropogoneae: Tripsacinae), a new species for
Queensland: circumscription and breeding system
E. J. Thompson
Summary
Thompson, E.J. (2017). Elionurus purpureus E.J.Thomps. (Panicoideae: Andropogoneae.
Tripsacinae), a new species for Queensland: circumscription and breeding system. Austrobaileya
10(1): 139-162. A new species of Elionurus Willd. endemic to northeast Queensland is described and
illustrated. It is distinguishable from E. citreus by the annual growth habit and spikelet morphology.
The leaf anatomy of the two Australian species of Elionurus is illustrated and compared. The
spikelet morphology of the two Australian species is contextualised within Elionurus, Tripsacinae
and Rottboellinae. A new distinguishing morphological character for Elionurus is presented, viz.
the proximal beak on the sessile spikelets, which is shared by the African genus Urelytrum Hackel
(Tripsacinae), and some Australian genera in other subtribes of Andropogoneae. The breeding system
that involves cleistogamy is discussed for the two Australian species of Elionurus.
Key Words: Poaceae, Andropogoneae, Rottboelliinae, Tripsacinae, Elionurus, Elionurus citreus,
Elionurus purpureus, Queensland flora, taxonomy, new species, cleistogamy, morphological
characters, leaf anatomy, stem anatomy, cultivated plants
E.J. Thompson, Queensland Herbarium, Department of Science, Information Technology and
Innovation, Brisbane Botanic Gardens, Mt Coot-tha Road, Toowong, Queensland 4066, Australia.
Email: [email protected]
Introduction
Elionurus Willd. is a genus of 15 species of spikelets (sessile and pedicellate) and a
tropical and subtropical caespitose grasses, rachilla (Stapf 1934; Renvoize 1978; Watson
13 perennial and two annual. Nine (six & Dallwitz 1992). These spikelet pairs have
endemic) species occur in Africa, five (two phylogenetic significance and are considered
endemic) from southern North America, by Zanotti et al. (2010) to be the evolutionary
four (three endemic) from South America, origin of the solitary spikelets in the sister
one from India, and one species recorded for tribe, Paniceae.
Australia and New Guinea (Clayton 1973;
Tripsacinae is currently represented
Clayton & Renvoize 1986; Watson & Dallwitz
worldwide by a further six genera, none of
1992). Elionurus has been placed in the tribe
which are native to Australia and includes the
Andropogoneae subtribe Rottboelliinae
significant food plant maize {Zea L.) (Soreng
on the basis of morphology (Watson &
et al. 2017). In the updated phylogeny of these
Dallwitz 1992) and a molecular phylogeny
grasses, Soreng et al. (2017) transferred five
by Soreng et al. (2015), although Kellogg
genera from Rottboelliinae to Tripsacinae that
(2015) placed it in Andropogoneae, incertae
had previously comprised only Tripsacum
sedis based on earlier molecular phylogenies.
L. and Zea, thus leaving Rottboelliinae
Soreng et al. (2017) in an updated phylogeny
with 16 genera. Species of Tripsacinae and
placed Elionurus in subtribe Triplacinae.
Rottboelliinae have unbranched inflorescences
Members of the tribe typically have racemose
and lack the conspicuous geniculate spiralled
inflorescences composed of disarticulating
awn on the sessile spikelets present in most
segments made up of a pair of differentiated
other subtribes of Andropogoneae (Clayton
1973; Clayton & Renvoize 1986; Watson
& Dallwitz 1992; Kellogg 2015), although
awnless spikelets also occur in subtribes
Chionachninae and Coicinae (Soreng et al.
Accepted for publication 21 July 2017
2017). Clayton (1973) used morphological
140 Austrobaileya 10(1): 139-162(2017)
characters in a numerical analysis of species of male and female inflorescences in different
Andropogoneae with awnless sessile spikelets parts of the same plant (Watson & Dallwitz
covering 22 of the 23 genera from Tripsacinae 1992). All of the species of Tripsacinae and
(except Zed) and Rottboelliinae and presented Rottboelliinae have bisexual flowers and
similarity diagrams for the genera. Clayton most are solely chasmogamous (CH), where
(1973) considered Rottboelliinae to be a anthers and stigmas emerge from florets with
recent evolutionary branch disjunct from the ability to outcross and thereby provide
other members of the tribe. gene flow (Watson & Dallwitz 1992; Simon
& Alfonso 2011). The one known exception
The previous single Australian species,
until now is the presence of cleistogamy (CL)
Elionurus citreus (R.Br.) Munro ex Benth.,
(self-pollination within a closed flower), in
lemon-scented grass, occurs along the
Rottboellia exaltata L.f. reported by Heslop-
northern tropical and eastern subtropical
Harrison (1959). Various types of CL have
coast of Australia and New Guinea (Simon &
been reported for species in other subtribes of
Alfonso 2011). This species is described and
Andropogoneae (Connor 1979; Campbell et
illustrated by Tothill & Hacker (1983) and
al. 1983; Watson & Dallwitz 1992; Culley &
Jacobs et al. (2008).
Klooster 2007).
Lemon-scented foliage also occurs in
This paper provides a taxonomic account
other species of Andropogoneae, where
of a new species of Elionurus with lemon-
fragrance of leaves has been used sometimes
scented foliage from north Queensland. The
as a taxonomic character in keys to genera
breeding systems of the two Australian species
by Stapf (1934) and Simon (2002). Lemon-
of Elionurus are presented and categorised
scented foliage is found in the Australian
according to current CL classifications
grass Cymbopogon ambiguus A.Camus
from the literature (Table 1). Morphological
(Australian lemon-scented grass), several
affinities of Elionurus to other genera of
species and cultivars of Cymbopogon
Rottboelliinae are also discussed.
Spreng. (lemon grass, citronella grass)
from Asia, and Elionurus muticus (Spreng.) Materials and methods
Kunth (lemon grass) from South America
Field survey at the site of the type collection
and Africa. The Asian and South African
of Elionurus purpureus was conducted in
grasses are commercial sources of lemon-
three successive years, April 2015, April 2016
scented essential oils (e.g., citral, citronellol,
and May 2017.
geraniol) (Soenarko 1977; Watson & Dallwitz
1992; Sangwan et al. 2001; Nakaharar et al. A comparative study of gross morphology
2003; Fuller et al. 2014; Kellogg 2015). Other and anatomy was made for E. purpureus
essential oils (predominantly campherenone) and E. citreus. Morphological data for
have been reported in leaves and roots of E. purpureus were obtained from four
Elionurus elegans Kunth, an annual from accessions at BRI which includes the type
Africa (Mevy et al. 2002). (Fig. 1). Spikelets from terminal and axillary
inflorescences were dissected to examine their
The breeding systems in grasses are highly
characters. Six topotypes from Queensland
diverse (Connor 1979) and in Panicoideae this
Herbarium (BRI) collections of E. citreus
is particularly so for the genera comprising
were selected for sampling (Appendix 1).
Tripsacinae as represented by Soreng et al.
These specimens were collected in the vicinity
(2017). Tripsacum L. and Zea provide unusual
of the type and are considered representative
diversity in breeding systems for subtribes
substitutes for the type, a collection by Robert
in Andropogoneae. Tripsacum has male and
Brown {Bennett no. 6176) made in 1802 from
female flowers in separate portions of the same
Northumberland Island, Queensland. Online
inflorescences, as is found in Chionachne
images of the isotype {Andropogon citreus
R.Br. (subtribe Chionachninae) and Zea has
R.Br.) at E, K and W were examined.
Thompson, Elionurus purpureus 141
Table 1. Morphological character differences between the Australian species of Elionurus
Character Elionurus purpureus Elionurus citreus
Growth habit annual perennial
Inflorescence type multiple racemes at nodes at least single racemes at nodes on
on cultivated plants cultivated plant and topotypes
Culms
Transverse section shape broadly concavo-convex narrowly concavo-convex
Anatomy
sclerenchyma along convex edge mostly 3 or 4 cells wide mostly 6-8 cells wide
Leaf blade and sheath
Distribution cauline mostly basal
Margin prickle hairs absent medium (60-70 p)
Abaxial surface
length of stomata (pm) 45-60 41-51
length of silica bodies (pm) 15-20 8-15
Margins and mid-vein indumentum smooth usually scabrid
Mid-vein obtusely keeled acutely keeled
Anatomy of vascular bundles
adaxial sclerenchyma absent present
Sessile spikelet (mid raceme*)
Total length (beak, body and lobes) 8.1-9.2, purple 10.6-13.1, pallid to pale pink.
(mm), colour at maturity rarely purplish
Lower glume
lobe length (mm) 2.6-3.2 5.5-7
body width x length (mm), texture 1.7-2 x 3.5-4.2, chartaceous 1.5-1.7 x 3.6-4.3, cartilaginous
indumentum type, orientation pubescent, appressed glabrous to pilose, ascending
hair length (mm) c. 0.2 c. 2
keeled margin of lower glume not winged narrowly winged
Upper lemma
margin hyaline, pilose, hairs c. 0.3 mm long hyaline, ciliate apically or glabrous
apex acute attenuate
Callus
length (mm) 1-2.3 1.8-2.7
* apical spikelets are smaller and basal larger
Pedicellate spikelet
Lower glume
width x length (mm), colour at 0.8-1.3 x 5.2-57, purple; c. 0.9 x 7.2-8.5, pallid to pale pink.
maturity, body, margins lanceolate, asymmetrical, 5-veined, rarely purplish, linear to narrow
1-keeled, both margins with oil lanceolate, asymmetrically.
streak 3-veined, 1-keeled, one margin with
oil streak
Upper glume subequal to lower glume, 5-veined, unequal to lower glume, 3-veined,
back rounded back laterally compressed
Anther length (mm)
Chasmogamous 0.9-2 1.3-2.7
Cleistogamous c. 0.8 0.7-1.8
Rachilla
Width x length (mm), shape 1.2-1.4 x 4.3-4.4, distinctly clavate 0.9-1.3 x 3.3-5, clavate
distinctly winged, unequally usually narrowly winged and
bilobed unequally bilobed, or not winged
Apex rim
Sub-apical beard
length of longest hairs (mm) 2.8-2.9 3.6-4.9
Pedicel
Width x length (mm), shape c. 0.8 x 2.5-3.5 0.5-0.6 x 2.9-4
142 Austrobaileya 10(1): 139-162(2017)
.
Fig. 1 Holotype specimen of Elionuruspurpureus (McDonaldKRM16860 & Thompson, BRI).
Thompson, Elionurus purpureus 143
Herbarium specimens and/or images scutellum. Germination was at ambient
of type specimens of all the other species temperature on damp tissue paper in a covered
of Elionurus and species in other genera transparent container in November 2016.
of Tripsacinae and Rottboelliinae were
Plants were cultivated in pots in a well-
examined in detail (Appendices 1 & 2).
drained potting medium in full sun in
Leaf and culm transverse sections were Brisbane, Australia (lat. 27° 26’ 37”S). Plants
prepared using a modified freehand sectioning were watered daily, unless there had been
version of the method described by Frohlich sufficient rain, to maintain continuously
(1984). Samples of herbarium material were moist potting medium. Watering rate was at
rehydrated by initial immersion in hot water about 7 mm per day, measured using a rain
and left to soak for up to several days. Leaves gauge, equating to about 1000 mm for the
from upper culms were used and sections wet season (December - March). Plants were
taken from near the middle of each leaf. Leaf occasionally fertilised with a commercial
samples were placed on a glass slide covered pelletised chicken manure.
with a glass slide cover that served as a cutting
Rainfall data from Climate Data Online
guide. Culm sections were cut without the use
(BoM) for weather stations near the collection
of the slide cover. Thin sections were cut using
localities of BRI accessions of E. purpureus
a razor blade while viewing under a binocular
were examined to investigate the potential
microscope at *40 magnification. Several
effect of soil moisture levels on plant growth
sections were made for both E. purpureus
and flowering. Frequency of rainy days of
and E. citreus. Three accessions of E. citreus
more than 5 mm and more than 10 mm are
were examined to capture variation and
recorded in Table 2 as a comparison with the
because some leaf blades retained distorted
watering regime of cultivated plants.
parenchyma following rehydration. Leaf
blades and culms of near equivalent width Spikelets from the cultivated plants were
were used for both species. examined in detail at flowering and fruiting
in April - June 2017. Spikelets from the upper
Leaf, spatheole and culm surface replicas
and lower halves of racemes were harvested on
were prepared using the method described by
a daily basis as they matured. The most distal
Hilu & Randall (1984).
spikelet of racemes disarticulated readily at
Micromorphology was studied from maturity. Ripe spikelets were gathered by
images taken using a compound binocular gently touching. The proportion of CH:CL
microscope at 5x, 10x? 20 x and 40 x for was examined by randomly selecting 20
transverse sections, and at 20x and 40x for spikelets for two batches, each batch from the
surface replicas. upper halves and lower halves of racemes.
Plants of E. citreus and E. purpureus were Botanical terminology follows Beentje
cultivated for three main purposes: to study (2010) and Harris & Harris (1994) for general
any impact of environment on growth habit, usage. An exception is the use of the term
effect of environment on the breeding system, convexo-concave to differentiate the shape of
and provide a supply of viable caryopses for the culm transverse section of E. purpureus.
further studies. Caryopses were taken from Anatomy descriptions and terminology follow
the type of E. purpureus and BRI accession, Metcalfe (1960), Ellis (1976, 1979), Renvoize
McDonald KRM11354 for E. citreus. The (1982) and Watson & Dallwitz (1992).
caryopses were scarified by scraping off
a small portion of pericarp just above the
144 Austrobaileya 10(1): 139-162(2017)
Taxonomy
Key to the Australian species of Elionurus
1 Perennial; spikelets pallid to pale pink; sessile spikelet with lobes longer
than body; body of lower glume pubescent; upper glume glabrous on
margin; NE NSW, EQld,N NT, NWA.E. citreus
1. Annual; spikelets purple at maturity; sessile spikelets with lobes shorter
than body; body of lower glume pilose or glabrous; upper glume pilose
on margin; N Qld.E. purpureus
Elionurus purpureus E.J.Thomps., sp. nov. long. Glumes dissimilar; lower glume 6.1-7.5
similar to E. citreus (R.Br.) Munro ex Benth. mm long; body 1.7-2 x 3.5-4.2 mm, broadest in
differing by the annual growth habit and middle, 9-veined, symmetrical, chartaceous;
purple spikelets 8.1-9.1 mm long with body of back flattened, pubescent with appressed pale
lower glume longer than the lobes and margin hairs c. 0.2 mm long or sometimes glabrous;
of upper glume pilose. Typus: Queensland. margins keeled, keels not winged, with two
Cook District: 0.8 km along Mt Spurgeon rows of pectinate white bristles to 1.3 mm
road from Mulligan Highway, Mt Carbine, long at 45° to margin decreasing in length
10 April 2015, K.R.McDonald KRM16860 & towards apex, sub-margins with broad dark
E.J.Thompson (holo: BRI). purple glabrous oil streak continuous with
lobes; apex 2-lobed, 2.6-3.2 mm long, obtuse,
Erect caespitose annual to 1.3 m high. Culms
lobes fused in lower third to half; upper glume
< 4 mm wide, shortly branched, nodes
4.2-4.5 mm long, symmetrical, lanceolate,
3-9; internodes purplish, smooth, hairless,
membranous, 3-veined, carinate, midvein
furrowed; nodes glabrous often purplish, half
with short erect proximal hairs; margins
to two-thirds of total length exserted from
winged, wing c. 0.3 mm wide, membranous,
sheath. Basal leaf sheaths purplish; culm
pilose; short appressed to ascending hairs
sheaths with scattered white hairs mostly near
on back, glabrous in upper 1/3, apex acute.
apical margins; collar margins with hairs to
Florets 2; lower floret neuter, lemma c. 3.5
3.3 mm. Ligule a fringed membrane, c. 0.9
mm long, lanceolate, hyaline, veins indistinct,
mm. Leaves cauline, blades up to 45 cm long
margin pilose, apex acute. Lower palea absent.
and 0.8-2 mm wide, discolorous, cauline,
Upper floret hermaphrodite, upper lemma,
keeled, pilose adaxially, hairs to 0.2 mm,
2.5-2.8 mm long, elliptic, hyaline, veins
margins smooth, inrolled on drying, lemon-
indistinct, margin pilose, apex obtuse. Upper
scented when crushed. Inflorescences of single
palea absent. Lodicules 2, c. 0.5 mm long.
spatheolate one-sided racemes, 4 to 13 cm
Anthers chasmogamous 3, 0.9-2 mm long,
long. Peduncle absent. Up to 9 nodes with 1-3
cream when fresh, or cleistogamous 3 and c.
one-noded branches each bearing a raceme;
0.8 mm long. Caryopses c. 1 x 0.6 x 2.5-27
axillary racemes exserted, partly exserted
mm, dorsiventrally compressed, broadest in
or enclosed with spatheole; spatheoles c.
the middle, bowed longitudinally, buff to light
4.5 mm wide and up to 13 cm long, pilose;
brown; scutellum c. 1.4 mm long; hilum c. 0.5
culms extending to 15 cm beyond spatheole.
mm long. Pedicellate spikelet neuter; glumes
Spikelets paired (sessile and pedicellate),
dissimilar, subequal, 5-veined, chartaceous,
dimorphic, purple at maturity, closely
lanceolate, lobes orientation parallel to body;
overlapping in two opposing staggered rows
lower glume 0.8-1.3 x 5.2-57 mm, dorsally
along disarticulating jointed axis; diaspore
compressed, back glabrous, asymmetrical,
composed of paired spikelets and rachilla.
broadest at the base, acute apex; 1-lobed,
Callus elliptical, c. 0.4 x 1-2.3 mm. Sessile
lobe orientation horizontal; margin 1-keeled,
spikelet fertile, dor si-ventral ly compressed,
with a single row of pectinate white bristles
1.4-1.6 x 8.1-9.2 mm , gradational (larger
c. 0.6 mm long decreasing in length apically,
from base to apex), proximal beak 2-2.2 mm
submargins with oil streak,; upper glume, c.
Thompson, Elionurus purpureus 145
0.8 x 4.5-5.3 mm, glabrous, symmetrical, key character annual, specimens key to E.
laterally compressed; back convex, carinate hensii K.Schum from the African continent,
in upper half, keel pilose with stiff parallel although examination of the online image
hairs c. 0.2 mm long; apex acute; 1-lobed, of the isosyntype provided confirmation
lobe orientation vertical; margins flat. Pedicel of the dissimilarity with E. hensii. If the
c. 0.8 x 2.5-3.5 mm, free from internode, growth habit is assumed to be perennial then
clavate, hollow, plano-convex in cross- specimens key to E. citreus but do not have
section, adaxial wall membranous and abaxial the lower glume with lobes longer than the
wall chartaceous; abaxial edge pubescent with body. Table 3 lists the character differences
white hairs, short and appressed along most between E. purpureus and E. citreus and Fig.
of length and with a longer sub-apically tuft 4 provides images of the respective spikelet
to 2.4 mm. Rachilla 1.2-1.4 x 4.3-4.4 mm, pairs for comparison.
dissimilar to pedicel, free from internode,
Diaspore dispersal in the Australian
clavate, hollow, plano-convex in cross-
species of Elionurus occurs via two modes.
section, adaxial wall membranous and abaxial
Most of the diaspores readily disarticulate
wall chartaceous, abaxial edge pubescent
from the racemes at maturity and can disperse
with short white appressed hairs; apex c. 1.2 x
by various vectors in similar ways to other
2.3 mm, oblique, adaxially flanged, unequally
grasses. Secondly, the basal spikelet pair
bilobed, subapical ring of white hairs to 2.8-
that is CH or CF of each raceme is resistant
2.9 mm long and longest on abaxial margin;
to disarticulation. This delayed release of
disarticulation scar c. 0.7 mm x 1.5 mm, flat,
the spikelet may have some advantage with
elliptical. Figs. 1, 2, 3 & 4.
dispersal allowing the spikelet to fall further
Additional specimens examined: Queensland. Cook from the mother plant after the culms collapse.
District: 9 km from Koolburra on the track S from
Koolburra to the Kimba road, Jun 1981, Clarkson 3699 Appendix 2 lists spikelet differences
(BRI); Conglomerate Creek, S of the Deighton Road, for all the species of Elionurus. This
on Escort Creek Holding, SE of Laura: Lot/Plan 198/
comparison shows that the Australian species
SP273726, Apr 2017, Forster PIF45151 & McDonald
exhibit morphological similarities between
(BRI, MEL); 0.8 km along Mt Spurgeon road from
Mulligan Highway, Mt Carbine, May 2017, Thompson themselves but are distinct from the other
EJT1083 (BRI). Cultivated. Ashgrove, Apr 2017, species. Only the Australian species have
Thompson MOR804 (BRI). the pedicellate spikelets composed of just the
Distribution and habitat: Elionurus two glumes and they always neuter. The non-
purpureus occurs west of the Great Dividing Australian species have developed pedicellate
Range in the range latitude 15°15’ to 16°45’S spikelets with two lemmas and anthers. This
and longitude 143°30’ to 145°15’E (Map 1). variation in development of the pedicellate
It is found in woodland mostly dominated by spikelet within a genus is uncommon in
eucalypts including Corymbia clarksoniana Andropogoneae but has parallels in Arthraxon
(D.J.Carr & S.G.M.Carr) K.D.Hill & Beauv. (van Welzen 1981). Furthermore, the
L. A. S. Johnson, Eucalyptus leptophleba Australian species have a distinctive character
F.Muell. and E. tetrodonta F.Muell. on sandy of the sessile spikelets that they share with
alluvial soil adjacent to intermittent creeks or most of the other species. The lower glumes
lagoons. have conspicuous submargins that Clayton
& Renvoize (1986) referred as a brown oil
Phenology: Elionurus purpureus flowers in streak and Watson & Dallwitz (1992) called
March to June during the wet season and early
glandular. Three species, Elionurus elegans
dry season.
Kunth, E. hirtifolius Hack, and E. royleanus
Notes: The identification key to Elionurus A.Rich. from Africa to NW India, lack this oil
species of the world provided by Renvoize streak. These species differ by having tufts of
(1978) was used to verify that E. purpureus hairs along the margins of the lower glume
is not an introduced species as specimens of the sessile spikelets instead of the row of
fail to key out satisfactorily. Using the parallel hairs present in the other species
146 Austrobaileya 10(1): 139-162(2017)
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Thompson, Elionurus purpureus 147
(see Fig. 4). However, the three species have have single slender culms to 30 cm high while
similarities to the Australian species by the all cultivated plants had multiple culms, one
lower glume of the pedicellate spikelets being main robust culm to 1.3 m high and up to 4
asymmetrical with the apex lobed or awned subordinate ones to 50 cm high. Cultivated
(Appendix 2). plants had much larger leaves, to 6 mm wide
x 42 cm long, compared to the type with
Harvesting of ripe spikelets from the
leaves 1-2 mm wide x 18 cm long. All of
cultivated plants of E. purpureus to collect
the cultivated plants closely resembled BRI
caryopses revealed a further character
accession Clarkson 3699 (Fig. 2).
uncommonly represented on herbarium
specimens. Spikelets on each raceme ripen There were also differences in the
and disarticulate successively until the basal inflorescences of cultivated plants. The
one that is resistant to detachment from the cultivated plants of E. purpureus had racemes
culm but ultimately falls. The specimens of to 13 cm long in fasciculate inflorescences
the species of Elionurus observed for this comprised of up to three racemes on branches
study frequently had over-mature racemes arising at as many as nine culm nodes. The
preventing observation of this phenomenon, holotype and accession Forster PIF45151
although it was present on one specimen of & McDonald have single racemes to 8 cm
E. citreus at BRI. The herbarium specimens long on short branches at up to three nodes.
usually had complete racemes and sometimes The cultivated plant of E. citreus had single
partially disarticulated ones. Permanent racemes at the nodes as was observed for the
retention of the basal spikelet is uncommon topotypes listed in Appendix 1.
in Australian Andropogoneae but has been
The study of the wet season rainfall data
reported by Veldkamp et al. (1986) and
presented in Table 2 resulted in equivocal
observed on herbarium specimens by the
conclusions. The sample size is too small for
author for Thaumastochloa C.E.Hubb., also
any clear trends but there is some evidence
Rottboelliinae.
to support a hypothesis that December rain
Very few of the caryopses obtained from of c. 100 mm may be responsible for plants
BRI specimen accessions were viable. Several developing the taller growth habit. This
caryopses from the holotype of E. purpureus seems plausible since no intermediate sized
germinated and two plants survived to plants were observed despite the presence of
maturity. One caryopsis of E. citreus from soil moisture gradients at least for some of
McDonald KRM11354 (BRI) germinated and the collection sites (pers. comm. PI. Forster).
the plant survived to maturity. The possibility of dimorphic growth habit
requires further investigation, particularly
Observations from the cultivated progeny
from further field survey.
of E. purpureus revealed striking differences
from the type that initially appeared to be the Breeding system
only collection. This promoted a review of
In order to categorise the CL found in
the 148 accessions of E. citreus at BRI. One
Elionurus, the classification schemes of CL
of the accessions, Clarkson 3699, matched
presented by eight authors were investigated.
the cultivated plants. At the point of nearing
These schemes are of two broad types in
completion of this manuscript another
terms of taxonomy, for flowering plants in
specimen, Forster PIF45151 & McDonald,
general and more specifically for grasses.
was incorporated at BRI. This accession
The classifications by Campbell et al. (1983)
is comprised of plants that are identical to
and Hackel (1906) provide more specific
the type in growth habit and inflorescence
categories relevant to Poaceae. In summary,
composition.
the schemes assess CL by the presence of
The difference in the growth habit of various morphological modifications of
the type from its cultivated progeny was the CH morph or whether CL is induced by
considerable. The plants comprising the type environmental conditions. The categories
148 Austrobaileya 10(1): 139-162(2017)
| QUEENSLAND HERRARIUWli »RlS»AHE~|
flora of QUEENSLAND COOK district M R 1 R 1
15-22S 143.54.E(,i,. l
coll
J.R. Clarkson 3699 25 June 1981
Elionurus citreus (R.Br*) Munro ex Benth,
I Fomily 1 HobHa* |*|»|P-|p|fl lyWi |j I ~
IGRAMI -JbWfrfl BRI “"P** *nlfV only- N°.tob» cited in popart.
9km from Koolburra on the track south from
Koolburra to the Kimba road.
Eucalyptus tetrodonta woodland*
An erect grass,
Common along the track.
QRS, NSW, CANB, PERTH, NT, K, US, PRE
dUtENSi.ANb
HER BARIUM
294155
brisbTnF
Fig. 2. Paratype of Elionurus purpureus (Clarkson 3699, BRI).