Dienstag, 4. September 2012

Plant of the Day (September 4th, 2012) - Senecio inaequidens DC.

The “Week of the Asteraceae” continues with Senecio inaequidens DC. from the Sub-family “Asteroideae”. In German, this plant is known as “Schmallblättriges Greißkraut” and in English as “Small-leafed groundsel” or “South African ragwort”. In Afrikaans, this species is known as “Bezemkruiskruid” (the home of this plant are the former Dutch colonies in South Africa).

S. inaequidens - Habitus

It's a herbaceous plant, which can reach heights between 20 and 60 centimetres (7.9 and 26.6 inches). Despite being a herb, the stalk can be woody at the base. It's well branched from basic. The leaves are very narrow, which is also the reason for the German name (“Schmalblättrig” is German for “narrow-leafed”). They are 6 and 7 centimetres long and only 1 to 3 millimetres broad. There is no petiole but the leaves are embracing the stalk with their leaf-base. Their margin is serrated finely.

S. inaequidens - inflorescences

As member of the Asteroideae, the heads of S. inaequidens consist of cygomorphic ray flowers in the periphery and disc flowers in the center. In both cases, the petals are golden yellow. Flowering time is between August and October. The ripe fruits are the typical, winged nuts of the Asteraceae, which I will explain at the end of the week in an extra article.

S. inaequidens -this is a typical, narrow leaf

As I said it before, S. inaqeuidens is native to the South Africa but the species is a Neophyte and can be found all other the world today. The plant owes this rapid spread to humans, which brought seeds of S. inaquidens to Europe with imported cotton at the end of the 19th century. First, S. inaequidens only grew near to harbours but with the construction of highways and railroads during the 20th century, the species also reached the inland.

S. inaequidens - inflorescence with ray flowers 
and disc flowers; typical for the Asteroideae

The natural habitat of S. inaequidens are rocky or grassy slopes on sand or gravel in a height between 1440 and 2850 metres. Outside of South Africa, this plant can be found at roadsides, railroad tracks, ruderal wastelands and rubble tips. It prefers warm places. In some regions, this species is considered as dangerous, but it's also a characteristic species of plant societies on renaturated, former industrial areas.

S. inaequidens - leaf (here you can see, how the
leaf-base embrace the stalk

S. inaequidens - as you can see, the stalk is well
branchend from the basic; the lower regions of
the stalk are also woody.

 Please note: Unfortunatly I've no good Photos of Senecio inaequidens DC. So, I've decided to post the article without any Photos first. I try to make some Photos during the Next day and will insert them here

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