Banksia Sphaerocarpa
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''Banksia sphaerocarpa'', commonly known as the fox banksia or round-fruit banksia, is a species of
shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...
or tree in the plant genus ''
Banksia ''Banksia'' is a genus of around 170 species in the plant family Proteaceae. These Australian wildflowers and popular garden plants are easily recognised by their characteristic flower spikes, and fruiting "cones" and heads. ''Banksias'' range i ...
'' (family
Proteaceae The Proteaceae form a family of flowering plants predominantly distributed in the Southern Hemisphere. The family comprises 83 genera with about 1,660 known species. Together with the Platanaceae and Nelumbonaceae, they make up the order Pro ...
). It is generally encountered as a high shrub, and is usually smaller in the north of its range. This species has narrow green leaves, and brownish, orange or yellow round flower
spikes The SPIKES protocol is a method used in clinical medicine to break bad news to patients and families. As receiving bad news can cause distress and anxiety, clinicians need to deliver the news carefully. By using the SPIKES method for introducing a ...
which may be seen from January to July. It is widely distributed across the
southwest The points of the compass are a set of horizontal, radially arrayed compass directions (or azimuths) used in navigation and cartography. A compass rose is primarily composed of four cardinal directions—north, east, south, and west—each sepa ...
of
Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...
, growing exclusively in sandy soils. It is usually the dominant plant in scrubland or low woodland. It is pollinated by, and is a food source for, birds, mammals, and insects. First described in 1810 by botanist Robert Brown, ''B. sphaerocarpa'' has a complicated
taxonomic Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...
history, and several
taxa In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...
once classified as part of a broadly defined ''B. sphaerocarpa'' have since been named as species in their own right. At present, most authorities recognise five
varieties Variety may refer to: Arts and entertainment Entertainment formats * Variety (radio) * Variety show, in theater and television Films * ''Variety'' (1925 film), a German silent film directed by Ewald Andre Dupont * ''Variety'' (1935 film), ...
; the largest variety, ''B. sphaerocarpa'' var. ''dolichostyla'' (ironcap banksia), is sometimes given species rank as ''B. dolichostyla''. ''B. sphaerocarpa'' is classified as Not Threatened under the Wildlife Conservation Act of Western Australia, although two varieties have been placed on the
Declared Rare and Priority Flora List The Declared Rare and Priority Flora List is the system by which Western Australia's conservation flora are given a priority. Developed by the Government of Western Australia's Department of Environment and Conservation, it was used extensively wi ...
—var. ''latifolia '' has been designated a Priority Two – Poorly Known taxon, and var. ''dolichostyla'' falls under Declared Rare Flora. None of the varieties are commonly seen in cultivation.


Description

''Banksia sphaerocarpa'' is a variable
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 ...
that differs in
plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...
size,
flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...
size and
leaf A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, ste ...
size across its range. The variability is marked enough that five
varieties Variety may refer to: Arts and entertainment Entertainment formats * Variety (radio) * Variety show, in theater and television Films * ''Variety'' (1925 film), a German silent film directed by Ewald Andre Dupont * ''Variety'' (1935 film), ...
are recognised. This species is generally a shrub tall. Plants are smaller in northern parts of the range, and grow larger in the southeast, with var. ''dolichostyla'' and rarely var. ''caesia'' reaching in height. All varieties bear a
lignotuber A lignotuber is a woody swelling of the root crown possessed by some plants as a protection against destruction of the plant stem, such as by fire. Other woody plants may develop basal burls as a similar survival strategy, often as a response t ...
, a swollen starchy
root crown A root crown, also known as the root collar or root neck, is that part of a root system from which a stem arises. Since roots and stems have quite different vascular The blood vessels are the components of the circulatory system that transport ...
from which the plant resprouts after
bushfire A wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identif ...
. The new stems are finely hairy but become smooth with maturity. The leaves are stiff, narrow and linear, and measure in length, on a petiole long. Leaves of most varieties are in width, and have a pointed tip, but var. ''latifolia'' has wider leaves, , and a blunter tip. The foliage is green, or a more pale blue-grey in the case of ''caesia'' and ''dolichostyla''. The
inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...
s are generally globular and measure in diameter, although larger forms, such as var. ''dolichostyla'', are more oval in shape. Flowering from January to July, the blooms are yellow, orange or brownish in colour. They take five to eight weeks to develop from bud to the finish of flowering. Anthesis takes place over two weeks, as the individual flowers open in a wave across the inflorescence. Three weeks before the flowers open, the spikes develop a strong musky smell. The flowers produce unusually large quantities of nectar; indeed some flowers produce so much that it drips to the ground. The old flowers fade to brownish and grey hues and remain curled around the flower spike. Up to 60  follicles develop on the globular spikes. The follicles are finely furred at first before becoming smooth and golden brown in colour, measuring long, high, and wide. The follicles are flat with pronounced 'shoulders', giving a rectangular appearance in cross section. Specimens of var. ''sphaerocarpa'' in the
Whicher Range Whicher Range, also known as Whicher Scarp, is a range in the South West region of Western Australia. The range has an average elevation of above sea level. Bounded by the Swan Coastal Plain to the west and the south, the Darling Scarp to th ...
,
Jarrah Forest Jarrah forest is tall open forest in which the dominant overstory tree is ''Eucalyptus marginata'' (jarrah). The ecosystem occurs only in the Southwest Botanical Province of Western Australia. It is most common in the biogeographic region named in ...
and the vicinity of Nannup have larger follicles. The seeds are wedge-shaped (cuneate), and measure in length, containing a smaller cuneate seed body measuring long by wide. Northern specimens can be quite small shrubs and may be hard to distinguish from '' B. micrantha'', which has smaller inflorescences and large flattened follicles.


Taxonomy

The earliest known botanical collection of ''B. sphaerocarpa'' occurred in December 1801, during the visit of HMS ''Investigator'' to
King George Sound King George Sound ( nys , Menang Koort) is a sound on the south coast of Western Australia. Named King George the Third's Sound in 1791, it was referred to as King George's Sound from 1805. The name "King George Sound" gradually came into use ...
. The specimen was collected from "A single plant observed between
Princess Royal Harbour Princess Royal Harbour is a part of King George Sound on the South coast of Western Australia, and harbour to Albany. On its northern shore is the Port of Albany. The name ''Princess Royal'' also appears in Albany in Princess Royal Fortress an ...
&
Oyster Harbour Oyster Harbour is a permanently open estuary, north of King George Sound, which covers an area of near Albany, Western Australia. The harbour is used to shelter a fishing fleet carrying out commercial fishing and the farming of oysters and mus ...
on a heath", and is credited to English botanist Robert Brown, though it is not possible to be certain on this point, as Brown incorporated the collections of junior expedition members into his herbarium without attribution. Neither Brown nor expedition horticulturist
Peter Good Peter Good (date of birth unknown, died 12 June 1803) was the gardener assistant to botanist Robert Brown on the voyage of HMS ''Investigator'' under Matthew Flinders, during which the coast of Australia was charted, and various plants collected. ...
mentions the collection in his diary. Brown published a formal description and name for the species in his 1810 ''
On the Proteaceae of Jussieu ''On the natural order of plants called Proteaceae'', also published as "On the Proteaceae of Jussieu", was a paper written by Robert Brown on the taxonomy of the plant family Proteaceae. It was read to the Linnean Society of London in the firs ...
''. He did not designate a
type specimen In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to a ...
(a specimen to be representative of the species) for the species, but the one specimen in his collection has since been formally declared the
lectotype In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes the ...
for the species. He also did not state the
etymology Etymology ()The New Oxford Dictionary of English (1998) – p. 633 "Etymology /ˌɛtɪˈmɒlədʒi/ the study of the class in words and the way their meanings have changed throughout time". is the study of the history of the Phonological chan ...
of 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 ...
, but it is accepted that the name derives from the
Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...
''sphaera-'' ("round"), and ''carpos'' ("fruit"), in reference to the shape of its infructescences. In Brown's arrangement of the genus, ''B. sphaerocarpa'' was placed between '' B. pulchella'' and '' B. nutans'' in
taxonomic sequence Taxonomic sequence (also known as systematic, phyletic or taxonomic order) is a sequence followed in listing of taxa which aids ease of use and roughly reflects the evolutionary relationships among the taxa. Taxonomic sequences can exist for taxa ...
; that is, an order that places related taxa next to each other. No subdivision of the genus was given, other than to separate a single distinctive species into a
subgenus In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between t ...
of its own. Swiss botanist
Carl Meissner Carl Daniel Friedrich Meissner (1 November 1800 – 2 May 1874) was a Swiss botanist. Biography Born in Bern, Switzerland on 1 November 1800, he was christened Meisner but later changed the spelling of his name to Meissner. For most of his 40 ...
published a more detailed arrangement in 1856, placing ''B. sphaerocarpa'' in
section Section, Sectioning or Sectioned may refer to: Arts, entertainment and media * Section (music), a complete, but not independent, musical idea * Section (typography), a subdivision, especially of a chapter, in books and documents ** Section sign ...
''Eubanksia'' because its inflorescence is a spike rather than a domed
head A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may ...
, and in
series Series may refer to: People with the name * Caroline Series (born 1951), English mathematician, daughter of George Series * George Series (1920–1995), English physicist Arts, entertainment, and media Music * Series, the ordered sets used in ...
''Abietinae'', whose members have inrolled leaf margins with no, or only very fine, serrations. Meissner also published a variety, ''B. sphaerocarpa'' var. ''glabrescens'', based on specimens collected by James Drummond; this is now considered a synonym of '' B. incana''.
George Bentham George Bentham (22 September 1800 – 10 September 1884) was an English botanist, described by the weed botanist Duane Isely as "the premier systematic botanist of the nineteenth century". Born into a distinguished family, he initially studi ...
's revision of ''Banksia'' for his 1870 ''
Flora Australiensis ''Flora Australiensis: a description of the plants of the Australian Territory'', more commonly referred to as ''Flora Australiensis'', and also known by its standard abbreviation ''Fl. Austral.'', is a seven-volume flora of Australia published be ...
'' overturned Meissner's series; instead, ''B. sphaerocarpa'' was placed in a new section, '' Oncostylis'', because of its hooked styles. Two varieties were recognised: Meissner's var. ''glabrescens'' was retained, and var. ''latifolia'' was newly described by Bentham. Bentham noted further variation amongst his specimens not accounted for by his varieties, stating "It is possible therefore that two species may be here confounded, but the specimens are insufficient for their distinction." For many years following Bentham's arrangement, the circumscription of ''B. sphaerocarpa'' was widely recognised as unacceptably broad.
William Blackall William E. Blackall (1876–1941) was a Western Australia medical doctor who made a substantial contribution to that state's botany. Born in Folkestone, Kent, England, he emigrated to Perth in 1905. His occupation was in medicine, but he is now be ...
informally published two varieties, var. ''pinifolia'' and var. ''violacea'' (properly '' Banksia violacea'') in his 1954 '' How to Know Western Australian Wildflowers''; and in 1966 the nurseryman Fred Lullfitz predicted that there were as many as eight taxa within the species. Several of these were recognised in George's revision of the genus for 1981 " The genus ''Banksia'' L.f. (Proteaceae)": '' B. micrantha'', '' B. grossa'', '' B. lanata'', '' B. scabrella'', '' B. telmatiaea'', '' B. leptophylla'' and ''B. incana''. George placed ''B. sphaerocarpa'' in subgenus ''Banksia'' because of its flower spike, section ''Oncostylis'' because its styles are hooked, and the resurrected series ''Abietinae'', which he constrained to contain only round-fruited species. He reduced variety ''latifolia'' to
synonymy A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...
with variety ''sphaerocarpa'', but conceded the species needed further review. Alex George reported that he thought ''Banksia sphaerocarpas closest relatives to be '' Banksia micrantha'' and '' B. grossa''. George's arrangement remained current until 1996, when
Kevin Thiele Kevin R. Thiele is currently an adjunct associate professor at the University of Western Australia and the director of Taxonomy Australia. He was the curator of the Western Australian Herbarium from 2006 to 2015. His research interests include ...
and
Pauline Ladiges Pauline Yvonne Ladiges (born 1948) is a botanist whose contributions have been significant both in building the field of taxonomy, ecology and historical biogeography of Australian plants, particularly Eucalypts and flora, and in science educa ...
published an
arrangement In music, an arrangement is a musical adaptation of an existing composition. Differences from the original composition may include reharmonization, melodic paraphrasing, orchestration, or formal development. Arranging differs from orches ...
informed by a
cladistic Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived char ...
analysis of morphological characteristics. They retained George's subgenera and many of his series, but discarded his sections. ''Banksia'' ser. ''Abietinae'' was found to be very nearly
monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...
, and so retained. It further resolved into four subclades, so Thiele and Ladiges split it into four subseries. ''Banksia sphaerocarpa'' appeared in the second of these, initially called the ' ''grossa'' clade' for its most basal member. As with George's classification, ''B. grossa'' and ''B. micrantha'' emerged as close relatives of ''B. sphaerocarpa''. This clade became the basis for new subseries ''Sphaerocarpae'', which Thiele defined as containing those species with lignotubers, styles loosely curling around the infructescence (although this trait was reversed in ''micrantha''), and "transversely aligned cells of the seed wing inner face". Other than the most basal ''B. grossa'', these species also have shouldered follicles. Having found ''B. micrantha'' to be more closely related than ''B. sphaerocarpa'' var. ''dolichostyla'' to the other varieties of ''B. sphaerocarpa'', they promoted var. ''dolichostyla'' to species rank as ''Banksia dolichostyla''. Morphological support for this was given by the fact that the old styles of var. ''dolichostyla'' are quite different from those of other varieties, being stouter, and tending not to curl around the infructescence as the others do. Questioning the emphasis on cladistics in Thiele and Ladiges' arrangement, George published a slightly modified version of his 1981 arrangement in his 1999 treatment of ''Banksia'' for the ''
Flora of Australia The flora of Australia comprises a vast assemblage of plant species estimated to over 30,000 vascular and 14,000 non-vascular plants, 250,000 species of fungi and over 3,000 lichens. The flora has strong affinities with the flora of Gondwana, ...
'' series of monographs. He added that he did not feel the characters of ''dolichostyla'' alone justified specific rank, being essentially merely larger in all parts than, but otherwise essentially similar to, var. ''caesia''. Therefore, he retained it as a variety of ''B. sphaerocarpa''. To date, George's 1999 arrangement remains the most recent comprehensive classification. The placement of ''B. sphaerocarpa'' in George's 1999 arrangement may be summarised as follows: :''
Banksia ''Banksia'' is a genus of around 170 species in the plant family Proteaceae. These Australian wildflowers and popular garden plants are easily recognised by their characteristic flower spikes, and fruiting "cones" and heads. ''Banksias'' range i ...
'' :: ''B.'' subg. ''Banksia'' ::: ''B.'' sect. ''Banksia'' (9 series, 50 species, 9 subspecies, 3 varieties) ::: ''B.'' sect. ''Coccinea'' (1 species) ::: ''B.'' sect. ''Oncostylis'' :::: ''B.'' ser. ''Spicigerae'' (7 species, 2 subspecies, 4 varieties) :::: ''B.'' ser. ''Tricuspidae'' (1 species) :::: ''B.'' ser. ''Dryandroideae'' (1 species) :::: ''B.'' ser. ''Abietinae'' :::::''B. sphaerocarpa'' :::::: ''B. sphaerocarpa'' var. ''caesia'' :::::: ''B. sphaerocarpa'' var. ''dolichostyla'' :::::: ''B. sphaerocarpa'' var. ''latifolia'' :::::: ''B. sphaerocarpa'' var. ''pumilio'' :::::: ''B. sphaerocarpa'' var. ''sphaerocarpa'' :::::'' B. micrantha'' :::::'' B. grossa'' :::::'' B. telmatiaea'' :::::'' B. leptophylla'' (2 varieties) :::::'' B. lanata'' :::::'' B. scabrella'' :::::'' B. violacea'' :::::'' B. incana'' :::::'' B. laricina'' :::::'' B. pulchella'' :::::'' B. meisneri'' (2 subspecies) :::::'' B. nutans'' (2 varieties) :: ''B.'' subg. ''Isostylis'' (3 species) A 2002 study by American botanists
Austin Mast Austin R. Mast is a research botanist. Born in 1972, he obtained a Ph.D. from the University of Wisconsin–Madison in 2000. He is currently a professor within the Department of Biological Science at Florida State University (FSU), and has been dire ...
and Tom Givnish yielded a surprise when molecular analysis mapped out ''dolichostyla'' as a sister taxon to its geographical neighbour ''B. violacea'', in a clade with ''B. laricina'' and ''B. incana''. ''B. micrantha'' and the other two varieties of ''B. sphaerocarpa'' form a separate clade nearby. Early in 2007, Mast and Thiele initiated a rearrangement of ''Banksia'' by merging ''
Dryandra ''Banksia'' ser. ''Dryandra'' is a series of 94 species of shrub to small tree in the plant genus ''Banksia''. It was considered a separate genus named ''Dryandra'' until early 2007, when it was merged into ''Banksia'' on the basis of extensiv ...
'' into it, and publishing ''B.'' subg. ''Spathulatae'' for the taxa having spoon-shaped
cotyledon A cotyledon (; ; ; , gen. (), ) is a significant part of the embryo within the seed of a plant, and is defined as "the embryonic leaf in seed-bearing plants, one or more of which are the first to appear from a germinating seed." The numb ...
s. They foreshadowed publishing a full arrangement once DNA sampling of ''Dryandra'' was complete; in the meantime, if Mast and Thiele's nomenclatural changes are taken as an interim arrangement, then ''B. sphaerocarpa'' is placed in ''B.'' subg. ''Spathulatae''. In 2008, George reinstated ''B. sphaerocarpa'' var. ''latifolia'', and published the new variety ''B. sphaerocarpa'' var. ''pumilio''.


Varieties

''Banksia sphaerocarpa'' is a widely distributed Western Australian species with four (or five if one includes var. ''dolichostyla'') varieties: * ''B. sphaerocarpa'' var. ''caesia'', first described by Alex George in his 1981 revision of the genus, grows larger than most other varieties, reaching , or occasionally , in height. It has yellow blooms and bluish grey foliage and is found in the central and southern Wheatbelt between the towns of Piawaning, Kojonup, Newdegate and Corrigin. * ''B. sphaerocarpa'' var. ''dolichostyla'' (Ironcap Banksia) was first described by Alex George in his 1981 revision of the genus. It is the largest of the varieties, encountered as a large shrub or small tree to high. It is larger in all parts than the other varieties, and has been considered a separate species. It is restricted to a small area from South Ironcap, east of Hyden, south to Mt Holland in the eastern Wheatbelt. * ''B. sphaerocarpa'' var. ''latifolia'' was originally described in a manuscript by Mueller and published by Bentham in 1870. It grows as a small rounded shrub to in height, and is restricted to the vicinity of the south coast between
Denmark ) , song = ( en, "King Christian stood by the lofty mast") , song_type = National and royal anthem , image_map = EU-Denmark.svg , map_caption = , subdivision_type = Sovereign state , subdivision_name = Danish Realm, Kingdom of Denmark ...
and the Porongorup Range, where it is found in low, open forest of ''
Eucalyptus marginata ''Eucalyptus marginata'', commonly known as jarrah, djarraly in Noongar language and historically as Swan River mahogany, is a plant in the myrtle family, Myrtaceae and is endemic to the south-west of Western Australia. It is a tree with rough ...
'' and '' E. calophylla''. * ''B. sphaerocarpa'' var. ''pumilio'', first described by Alex George in 2008, is a small shrub less than a metre high. It is found from
Tathra National Park Tathra National Park is a national park in Western Australia, located north of Perth between the towns of Eneabba and Carnamah on Winchester-Eneabba Road. The name is derived from a Noongar word meaning "beautiful place". Description The pa ...
east of Eneabba south to the Chittering valley. Its subspecific name is derived from the
Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
''pumilio'' "small", relating to the flowers. * ''B. sphaerocarpa'' var. ''sphaerocarpa'' is widely distributed from the
Darling Plateau Darling is a term of endearment of Old English origin. Darling or Darlin' or Darlings may also refer to: People *Darling (surname) *Darling Jimenez (born 1980), American boxer *Darling Légitimus (1907–1999), French actress Places Australia ...
east of Perth to the
Whicher Range Whicher Range, also known as Whicher Scarp, is a range in the South West region of Western Australia. The range has an average elevation of above sea level. Bounded by the Swan Coastal Plain to the west and the south, the Darling Scarp to th ...
in the southwest, and southeast to the
Stirling Range The Stirling Range or Koikyennuruff is a range of mountains and hills in the Great Southern region of Western Australia, south-east of Perth. It is over wide from west to east, stretching from the highway between Mount Barker and Cranb ...
. Populations north of Perth once referable to it are now classified as var. ''pumilio''.


Distribution and habitat

''Banksia sphaerocarpa'' is distributed widely across southwestern Western Australia—from Eneabba in the north, south to the
Whicher Range Whicher Range, also known as Whicher Scarp, is a range in the South West region of Western Australia. The range has an average elevation of above sea level. Bounded by the Swan Coastal Plain to the west and the south, the Darling Scarp to th ...
, Nannup, Albany and Jerramungup, and eastwards to the vicinity of Hyden. It is mainly found on sandy soils in flat or gently sloped areas in
shrubland Shrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominated by shrubs, often also including grasses, herbs, and geophytes. Shrubland may either occur naturally or be the result of human activity. It m ...
, mallee or open woodland.


Conservation

As a species, ''B. sphaerocarpa'' is not considered to be under threat, but two of the five varieties have been placed on the
Declared Rare and Priority Flora List The Declared Rare and Priority Flora List is the system by which Western Australia's conservation flora are given a priority. Developed by the Government of Western Australia's Department of Environment and Conservation, it was used extensively wi ...
. ''B sphaerocarpa'' var. ''dolichostyla'' has been gazetted as "Declared Rare Flora – Extant" under the
Wildlife Conservation Act 1950 The ''Wildlife Conservation Act 1950'' is an act of the Western Australian Parliament that provides the statute relating to conservation and legal protection of flora and fauna. Text was copied from this source, which is available under Attrib ...
. ''Banksia sphaerocarpa'' var. ''latifolia'', though not afforded legislative protection, has been identified as a "Priority Two – Poorly Known" taxon, because so few populations are known.


Ecology

Various animals, including mammals, birds, and insects such as bees, wasps, ants and beetles, have been recorded visiting ''Banksia sphaerocarpa'' inflorescences, including the
colletid The Colletidae are a family of bees, and are often referred to collectively as plasterer bees or polyester bees, due to the method of smoothing the walls of their nest cells with secretions applied with their mouthparts; these secretions dry int ...
bee species '' Hylaeus sanguinipictus''. Botanist
Stephen Hopper Stephen Donald Hopper AC FLS FTSE (born 18 June 1951) is a Western Australian botanist. He graduated in Biology, specialising in conservation biology and vascular plants. Hopper has written eight books, and has over 200 publications to his n ...
found pollen of ''B. sphaerocarpa'' on New Holland honeyeaters (''Phylidonyris novaehollandiae'') and
honey possum The honey possum or noolbenger (''Tarsipes rostratus''), is a tiny species of marsupial that feeds on the nectar and pollen of a diverse range of flowering plants. Found in southwest Australia, it is an important pollinator for such plants as '' ...
s (''Tarsipes rostratus'') at Cheyne Beach in a
field study Field research, field studies, or fieldwork is the collection of raw data outside a laboratory, library, or workplace setting. The approaches and methods used in field research vary across disciplines. For example, biologists who conduct fi ...
published in 1980. Knowledge of the
breeding system A mating system is a way in which a group is structured in relation to sexual behaviour. The precise meaning depends upon the context. With respect to animals, the term describes which males and females mating, mate under which circumstances. Reco ...
of ''B. sphaerocarpa'' comes from a 2009 study of
genetic structure Genetic structure refers to any pattern in the genetic makeup of individuals within a population. Genetic structure allows for information about an individual to be inferred from other members of the same population. In trivial terms, all popul ...
within and across fragmented plant populations, which made a
case study A case study is an in-depth, detailed examination of a particular case (or cases) within a real-world context. For example, case studies in medicine may focus on an individual patient or ailment; case studies in business might cover a particular fi ...
of ''B. sphaerocarpa'' var. ''caesia'' populations in the vicinity of Dongolocking, where the landscape has been severely fragmented by
land clearing Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated d ...
. Very little
self-pollination Self-pollination is a form of pollination in which pollen from the same plant arrives at the Stigma (botany), stigma of a flower (in flowering plants) or at the ovule (in gymnosperms). There are two types of self-pollination: in autogamy, pollen i ...
was observed. Most mating was between plants in the same population, but inter-population mating accounted for 15–33% of seed, a "very significant contribution... to overall reproductive dynamics". This figure was lowest in the smallest populations, which also exhibited lower rates of germination, smaller plants, and less genetic diversity than larger populations. One possible interpretation of this is that interpopulation mating confers a fitness advantage. There was also evidence of fine-scale genetic structure, with plants tending to be more closely related to nearby plants than to more distant plants. The authors suggest that gene flow was probably always limited in these populations, even before they were fragmented. ''Banksia sphaerocarpa'' is one of five closely related ''Banksia'' species that have highly unusual flower
nectar Nectar is a sugar-rich liquid produced by plants in glands called nectaries or nectarines, either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualists ...
. Whereas other ''Banksia'' species produce nectar that is clear and watery, the nectar of these species is pale yellow initially, but gradually becomes darker and thicker, changing to a thick, olive-green mucilage within one to two days of secretion, and eventually becoming "an almost black, gelatinous lump adhering to the base of the flowers". It was first noted by Byron Lamont in 1980; he attributed it to
cyanobacteria Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blu ...
that feed off the nectar
sugar Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose, fructose, and galactose. Compound sugars, also called disaccharides or double ...
s. Noting that many of these cyanobacteria had
heterocyst Heterocysts or heterocytes are specialized nitrogen-fixing cells formed during nitrogen starvation by some filamentous cyanobacteria, such as '' Nostoc punctiforme'', ''Cylindrospermum stagnale'', and ''Anabaena sphaerica''. They fix nitrogen fr ...
s, he speculated that they aid the plant by fixing atmospheric nitrogen, which is then washed off the flower heads by rain, and absorbed by the proteoid root mat. This purported
symbiosis Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...
was investigated by Barrett and Lamont in 1985, but no evidence of nitrogen fixing was found. Further investigation by Markey and Lamont in 1996 suggested that the discolouration is not caused by cyanobacteria or other microorganisms in the nectar, but is rather "a chemical phenomenon of plant origin". Their analyses indicated that the nectar had unusually high levels of sugar and free
amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha am ...
s, but three of these species, including ''B. sphaerocarpa'', have since been shown to have normal nectar sugar compositions. Like most Western Australian ''Banksia'' species, ''B. sphaerocarpa'' is susceptible to dieback from the soil-borne water mould ''
Phytophthora cinnamomi ''Phytophthora cinnamomi'' is a soil-borne water mould that produces an infection which causes a condition in plants variously called "root rot", "dieback", or (in certain '' Castanea'' species), "ink disease". The plant pathogen is one of the wo ...
''. In one experiment, 43% of plants were dead within three months of inoculation, and the species was therefore rated as "moderately susceptible". In another experiment, 37% of plants were dead within three months, and 85% within a year; yet this study rated the species' susceptibility as "high". In the latter study, it took 35 to 40 days for the death rate to reach its maximum, and thereafter the death rate continued at that level throughout the year, only dipping slightly in the dry summer months.


Cultivation

None of the varieties of ''Banksia sphaerocarpa'' are commonly seen in cultivation. They are difficult to grow in the wetter conditions of Australia's east coast. Trials with
grafting Grafting or graftage is a horticultural technique whereby tissues of plants are joined so as to continue their growth together. The upper part of the combined plant is called the scion () while the lower part is called the rootstock. The succ ...
have been very limited and results have been poor. Otherwise, they adapt well to gardens with good drainage, sandy soils and sunny aspects in drier and Mediterranean (winter moisture) climates, and are also frost tolerant. They are good bird-attracting plants, and flower when not much else is in flower. Seeds do not require any treatment prior to
sowing Sowing is the process of planting seeds. An area or object that has had seeds planted in it will be described as a sowed or sown area. Plants which are usually sown Among the major field crops, oats, wheat, and rye are sown, grasses and leg ...
, and take 20 to 48 days to
germinate Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, fer ...
.


Notes


References


External links

* * * {{featured article sphaerocarpa Eudicots of Western Australia Taxa named by Robert Brown (botanist, born 1773) Plants described in 1810 Endemic flora of Southwest Australia