''Senecio minimus'' (syn. ''Erechtites minumus''), commonly known as toothed fireweed and coastal burnweed, is a species of

plant Plants are predominantly Photosynthesis, photosynthetic eukaryotes of the Kingdom (biology), kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all curr ...

in the sunflower family. It is native to Australia (all 6 states) and

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 List of islands of New Zealand, smaller islands. It is the ...

, and also naturalized on the Pacific Coast of the United States ( Washington,

Oregon Oregon () is a state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idah ...

, and

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the ...

).Atlas of Living Australia, ''Senecio minimus'' Poir., Toothed Fireweed
/ref>Calflora taxon report, University of California, ''Senecio minimus'' Poir., Coastal burnweed
/ref>

Description

''Senecio minimus'' is an

annual Annual may refer to: * Annual publication, periodical publications appearing regularly once per year **Yearbook **Literary annual * Annual plant *Annual report *Annual giving *Annual, Morocco, a settlement in northeastern Morocco *Annuals (band), ...

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

herb up to tall. Leaves are toothed but not

pinnately lobed The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular o ...

. One plant can produce as many as 200 yellow or purple

flower heads A pseudanthium (Greek for "false flower"; ) is an inflorescence that resembles a flower. The word is sometimes used for other structures that are neither a true flower nor a true inflorescence. Examples of pseudanthia include flower heads, compos ...

, each with many small

disc floret The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae we ...

s but no

ray florets The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae we ...

.Flora of North America, ''Erechtites minimus'' (Poir.) DC.
/ref> Its features include taproots with lateral roots that branch out into the soil. ''Senecio minimus'' has a tall upper stem, a mid stem and a basal stem. There is a leaf base from the mid stem which supports the leaves of the plant which are sized around 80-250mm long and are spaced evenly. The upper leaves of this species are narrow and linear shaped. They become widest at the auricles at the base of the leaf. The florets of ''Secenio minimus'' have triangular corolla lobes which become thicker apically. The stems are erect and are a dark green-purple colour. They have very small hairs below the mid stem, but above the stem it becomes more glabrous.

Distribution

''Senecio minimus'' is a species that is found not only in New Zealand and Australia but all over the world. It is naturally occurring in the US in states including California, Oregon and Washington. It is found in coastal parts of England. This species is also found in Australia in South-east Queensland, New South Wales, Tasmania, as well as parts of southwest and southeast Australia. ''Senecio minimus'' is indigenous to New Zealand and is found in the coastal areas around the Chatham Islands and Stewart Island. The species has been found in Malbrough, Nelson, Canterbury, Westland and Southland in the South Island of New Zealand as well as in North and South Auckland, Taranaki, Gisborne, Hawkes Bay and Wellington in the North Island. ''Senecio minimus'' prefers a coastal environment but occasionally extends to more subalpine environments in New Zealand. The species' ideal habitat is usually associated with forest margins. ''Senecio minimus'' is most commonly found in and around coastal habitats with forest or bush cover. It is also found in places where running water is present as well as shade from the sun. It can be seen in pasture land as well as tussock areas.

Lifecycle

''Senecio minimus'' is an angiosperm which is a flowering plant. It flowers throughout the year but is more predominant in the summer months. Angiosperms produce fruit that contains the seeds of the plant. ''Senecio minimus'' fruit throughout the year but most often produce during late summer and early autumn. Seeds will only germinate if conditions are favourable during the summer period. Seeds are dispersed via wind. After this species flowers, it goes to seed. These seeds are found in the capitulum. The capitulum is the head of a stalk, which consists of a flat, dense cluster of small florets. When it goes to seed, seeds are released and dispersed by the wind. Wind carries the seeds to a new destination where, if not dormant, the seeds germinate almost immediately.

Interactions

''Senecio minimus'' grows in coastal areas. Coastal soils are usually a combination of clay, sand and silt, with the dominant soil texture being a clay loam. ''Senecio minimus'' is the host to three endemic herbivores: The magpie moth ('' Nyctemera annulata''), the blue stem borer (''

Patagoniodes farnaria ''Patagoniodes'' is a snout moth genus in the subfamily Phycitinae described by Rolf-Ulrich Roesler in 1969. It currently contains seven species, of which ''Patagoniodes popescugorji'' is the type species Species *'' Patagoniodes farinaria'' ...

''), and the Senecio gall fly (''

Tephritis fascigera ''Tephritis fascigera'' or the Senecio gall fly is a species of fruit fly that is endemic to New Zealand. It is a member of the genus ''Tephritis'' of the family Tephritidae, one of two families that are called "fruit flies". Its grubs gall ...

''). These species use ''Senecio minimus'' for feed and an environment to inhibit. ''Senecio minimus'' influences the abundance of insects on and around it. This is because it is a species that insects commonly use to colonise.

Further information

In Otago, the conservation status of Senecio minimus is threatened. The Otago conservation management strategy classifies it as nationally vulnerable.

References

{{Taxonbar, from1=Q15603295, from2=Q5385394 Senecioneae Flora of Australia Flora of New Zealand Plants described in 1817