''Bossiaea walkeri'', commonly known as cactus bossiaea, cactus pea,
or Walker's stick bush
is a
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of
flowering plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...
in the pea family (
) and is
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...
to southern mainland Australia. It is a rigid, much-branched shrub with flattened, winged
cladodes and red, pea-like flowers between July and November in the species' native range.
Description
''Bossiaea walkeri'' is a rigid, much-branched shrub that grows up to high and wide and is more or less
glabrous
Glabrousness (from the Latin ''glaber'' meaning "bald", "hairless", "shaved", "smooth") is the technical term for a lack of hair, down, setae, trichomes or other such covering. A glabrous surface may be a natural characteristic of all or part of ...
. The stems and branches are flattened and winged, ending in cladodes wide. The leaves, when present, are reduced to scales about long, occasionally more or less round and up to long near the base or on young plants. The flowers are long and are borne singly at nodes on the cladodes on a pendent
pedicel
Pedicle or pedicel may refer to:
Human anatomy
*Pedicle of vertebral arch, the segment between the transverse process and the vertebral body, and is often used as a radiographic marker and entry point in vertebroplasty and kyphoplasty procedures
...
up to long with overlapping, broadly egg-shaped
bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...
s up to long at the base. There are egg-shaped
bracteoles
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...
long on the pedicel, but that fall off as the flower opens. The five
sepal
A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...
s are about long and joined at the base, forming a tube long, the two upper lobes long and much longer than the lower three. The
standard Standard may refer to:
Symbols
* Colours, standards and guidons, kinds of military signs
* Standard (emblem), a type of a large symbol or emblem used for identification
Norms, conventions or requirements
* Standard (metrology), an object th ...
petal is usually red, long and shorter than the
wings
A wing is a type of fin that produces lift while moving through air or some other fluid. Accordingly, wings have streamlined cross-sections that are subject to aerodynamic forces and act as airfoils. A wing's aerodynamic efficiency is expresse ...
and
keel
The keel is the bottom-most longitudinal structural element on a vessel. On some sailboats, it may have a hydrodynamic and counterbalancing purpose, as well. As the laying down of the keel is the initial step in the construction of a ship, in Br ...
that are each about long. The wings are salmon pink and the keel is deep red. Flowering occurs between July and November and the fruit is an oblong
pod about long.
Taxonomy
''Bossiaea walkeri'' was first formally described in 1861 by
Ferdinand von Mueller
Baron Sir Ferdinand Jacob Heinrich von Mueller, (german: Müller; 30 June 1825 – 10 October 1896) was a German-Australian physician, geographer, and most notably, a botanist. He was appointed government botanist for the then colony of Vict ...
in ''
Fragmenta Phytographiae Australiae'' from specimens collected by Alexander Walker on hills between the
Lachlan and
Murrumbidgee River
The Murrumbidgee River () is a major tributary of the Murray River within the Murray–Darling basin and the second longest river in Australia. It flows through the Australian state of New South Wales and the Australian Capital Territory, desce ...
s.
The
specific epithet
In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...
(''walkeri'') honours the collector of the
type specimens.
Distribution and habitat
Cactus bossiaea grows in
mallee, low open woodland, creek beds and rocky outcrops and occurs in Western Australia, South Australia, Victoria and New South Wales. It is found from near
Shark Bay
Shark Bay (Malgana: ''Gathaagudu'', "two waters") is a World Heritage Site in the Gascoyne region of Western Australia. The http://www.environment.gov.au/heritage/places/world/shark-bay area is located approximately north of Perth, on the ...
in Western Australia, through the south-west of the state to southern South Australia, the
Murray River
The Murray River (in South Australia: River Murray) (Ngarrindjeri: ''Millewa'', Yorta Yorta: ''Tongala'') is a river in Southeastern Australia. It is Australia's longest river at extent. Its tributaries include five of the next six longest r ...
and
Wyperfeld National Park
The Wyperfeld National Park is the third largest national park in Victoria, Australia, located in the Mallee district, approximately northwest of Melbourne, The national park was declared in 1921 and expanded significantly to protect of malle ...
in Victoria, and to inland New South Wales.
The species is rare in Victoria, where it is listed as "endangered" under the Victorian Government ''
Flora and Fauna Guarantee Act 1988
The ''Flora and Fauna Guarantee Act 1988'', also known as the ''FFG Act'', is an act of the Victorian Government designed to protect species, genetic material and habitats, to prevent extinction and allow maximum genetic diversity within the Au ...
''.
Ecology
The pendent flowers and the unusual shape of the flower parts of ''B. walkeri'' suggest that it is bird-pollinated. Honeyeaters and blue wrens have been observed visiting the flowers.
Reproduction
The 2cm flowers are produced between July and November. They will often flower after seed has set to take full advantage of additional rainfall after a dry period.
The fruit is a hairless, flattened 6cm by 1cm pod that contains brown seeds. The pods begin green but mature to brown, the seeds become ripe usually 2 to 3 months after flowering has finished.
Then on a hot day the pods will explode to disperse the seed several metres. Birds are the primary pollinators, but small animals and insects also contribute.
Uses
Use in horticulture
This species is described as "decorative" and can be propagated from seed or from cuttings. It can be grown in full sun or part shade, is drought and frost tolerant but needs relatively dry, well-drained soil.
Other uses
''Bossiaea walkeri'' produces a very distinct honey, although it appears to have no pastoral value.
References
{{Taxonbar, from=Q10740874
walkeri
Mirbelioids
Flora of New South Wales
Flora of Victoria (Australia)
Rosids of Western Australia
Flora of South Australia
Taxa named by Ferdinand von Mueller