Samstag, 27. Oktober 2012

Plant of the Day (October 27th, 2012) - Lythrum salicaria L.

Today's “Plant of the Day” is Lythrum salicaria L. from the family with the same name: the Lythraceae. In English, this species is known as “Purple loosestrife” and in German, it's called “Gewöhnlicher Blutweiderich”.

L. salicaria - habitus

L. salicaria is a perennial plant, which can reach heights between 50 and 100 centimetres (19.7 to 39.4 inches) but larger individuals with 200 centimetres (78.7 inches) are also possible. The stalk grows upright and is only branched in its lower regions. In this region, there are also some hairs, but the rest is bald.

The leaves are narrow to lanceolate. They sit directly at the stalk and have heart-shaped leaf-bases. Leaves of lower regions follow the decussate leaf-pattern, while the leaves of the upper regions follows the alternating leaf-pattern. Another feature are the protruding leaf-veins.

L. salicaria - leaf and leaf-vein

L. salicaria is a hemi-cryptophyte with a creeping rhizome.

The inflorescences are fake ears (actually a Dichasium), with many small flowers. Flowering time is between July and September. Each flower has six long and narrow petals, which have a deep purple colour.

L. salicaria - inflorescence

It's also interesting, that the stamen and the stylus of each plant may vary in their length. The three main types are
  • long stylus and short stamens
  • medium long stylus and short stamens
  • short stylus and long stamen
The function of these different lengths was unknown for a long time, but Charles Darwin found, that the pollination of individuals with the same lenght was much more successful than in species of different one.

The ripe fruits are capsules with a lot of seeds within it. The seeds are covered with small hairs, which allows them to hold on ducks and other waterbirds for spreeding.

 L. salicaria - flowers ("short stylus" type)

L. salicaria is native to Eurasia, North Africa and Europa but can also be found as neophyte in North America as neophyte. It grows on warm and wet places. Such places are wetlands, riverbanks or flood area. However, the species is also very common on ruderal wastelands and roadsides. It's rare in the highlands.

The species was also used as medicinal plant. All parts of the plant, especially the Rhizome and the stalk, contains Salicarin and other ingredients, which have a haemostatic effect. Because of this, L. salicarium was used to stop bleeding.

Mittwoch, 24. Oktober 2012

Excursus: Erinaceus europaeus L.

Today's Article isn't about a plant but about an animal. This species is Erinaceus europaeus L.. In Germany, this animal is known as “Braunbrustigel” and in English as “European Hedgehog”. It belongs to the Erinacaeideae (Hedgehogs).

E. europaeus - the animal is tens and erects its bristles,
ready to roll up

The European Hedgehog can reach a maximum length between 20 and 30 centimetres. The most distinctive feature are the long, spiky bristles, which are used by the hedgehog for self-defence. In danger, the Hedgehog curls up and forms a stinging ball with its bristles. These bristles are normally brown, but there are also blonde variants.

It is a loner, but has no strong territorial behaviour, so territories of individual animals can overlap. Each territorial includes an area of nearly 100 hectare. In this area, the hedgehog builds some small nests, which are used for resting. In between, it wanders through its territory in search of food. Hedgehogs are nocturnal and eat insects, snails and worms.

E. europaeus (circle) - the animal feels unobserved, the bristles
are applied while it wanders thorugh undergrowth 

Natural enemies of E. europaeus are the Golden Eagle (Aquila chrysaetos; “Steindadler” in German), the Eurasian Eagle-owl (Bubo bubo; Uhu in German) and the badger (Meles meles = Dachs). The badger is strong enough to open a curled up hedgehog and while the Eagle-Owl and the Golden Eagle can kill even a protected hedgehog with its claws. Because of this, you can find remains of hedgehogs (like spikes and skin) near the location of nests of B. bubo (e. g. quarries) *). Other enemies are foxes and weasels.

E. europaeus - even after a few minutes, the tense animal
remains motionless and observes possible dangers

Mating time is between April and May; gestation lasts 35 days. Litter size is normally ten youngs. The hedgehog holds hibernation, which lasts from October to April.

The species is native to Europe .Its natural habitat are fields which are punctuated by small forests, hedges and wild grasses. However, these habitats have become very rare in Europe, and so it can also be found in gardens, parks or the outskirts.

*) Thanks to Christopher Schwerdt for this supplement 

Montag, 22. Oktober 2012

Plant of the Day (October 22nd, 2012) - Epilobium hirsutum L.

Today's “Plant of the Day” is Epilobium hirsutum L. from the Onagraceae family. In English, this species is known as “Great hairy willowherb” and in German as “Zottiges Weidenröschen”.

E. hirsutum  in its natural habitat

Its a large perennial plant, which can reach heights between 50 and 150 centimetres (19.7 to 59.1 inches). The name hirsutum (Latin for “hairy”) refers to the stalk, which is very hairy. While the lower parts are covered with long hairs, the upper regions contrast with short glandular hairs. The stalk is nearly round.

E. hirsutum - Stalk with hairs

The leaves are long and lanceolate. The upper leaves follow the decussate leaf-pattern; the lower leaves are alternating. They have a serrated margin, wherein the teeth are directed towards the tip. Their leaf-bases encircle the stem completely. The leaves are also covered with hairs. This covering ranges from almost bald over fleecy to felty.

 E. hirsutum - leaves

The inflorescences are simple cymes with large, radial flowers (4 to 8 centimetres in diameter). There are four sepals and four petals. The petals are heart-shaped and have a bright, purple colour. Flowering time is between June and September. The young fruits are long capsules, which are also hairy but they become bald with age. The seeds are very light and are able to swim. This is also the main mechanism of spreading.

E. hirsutum - flower (here you can also see the stamens
and the fourd divided stigma in the centre)

The plant also have a rhizome, which is used for vegetative spreading. This Rhizomes are uneatable for the cattle. Therefore, E. hirsutum grows very quick on meadows.

E. hirsutum is native to the “Old World” (Europe, Asia and North Africa) but can also be found in North America and Australia as Neophyte. The species prefers wet and warm places and can be found at the shores of lakes, swamps and even ditches. It grows also on fresh meadows. It's a very common plant.

Mittwoch, 17. Oktober 2012

Plant of the Day (October 17th, 2012) - Dipsacus fullonum L.

The last two weeks, I was a little bit busy so there were only one Article per week. But now, I will return to the old rhytm with two new Postings per week. So, today's “Plant of the Day” is Dipsacus fullonum L. from the Caprifoliaceae *). In English, this species is known as “wild teasel” and in German as “Wilde Karde”.

D. fullonum - habitus

Wilde Karde” is a large, herbaceous and biennial plant, which can reach heights between 70 and 200 centimetres (27.6 to 78.7 inches). The stalk grows upright and is very spiky, because it is covered with upright sharp bristles.
The basal leafs are arranged in a rosette, while the foliage leaves follow the decussate leaf pattern. They are lanceolate and have a slightly notched margin (but this doesn't have to be pronounced). The leaf-bases of two opposite leafs are grown together; forming a bag-like structure, which is used to collect rainwater (the name “dipsacus” comes from the word “Dipsa”, which means “thirst” in English. The reason for this that the collected rainwater was drunk by thirsty wanderers and animals).
The bracts are very long and protrudes above the inflorescence significantly.

D. fullosum - on this picture, you can see
the fused leaf-bases

The distinctive inflorescences are terminal heads, which have a cylindrical or conical shaped. Each head consists of many, small flowers with four sepals and petals. The petals are fused to a corolla tube. They have a violet colour.
Flowering time is between July and August. The running of the flowering is pretty interesting, because the flowers in the middle of an inflorescence are the first one, which opens.

D. fullosum - old inflorescence

The ripe fruits are Archenes; similar to the fruits of the Asteraceae. The mechanism of spreading is also nearly the same. The plant throws away its fruits, which remain on fur hanging. Ripening time is between September and October.

D. fullosum - closer look at the same old inflorescence

 D. fullonum is native to Eurasia and North Africa but can also be found as neophyte in North America. It grows on warm and wet places. Such places are wetlands, riverbanks or flood area. However, the species is also very common on ruderal wastelands and roadsides.

D. fullosum - habitus

In ancient time, D. fullonum was used as medicinal plant. Especially the roots were used to cure jaundice and stomach diseases but also to cure stye and warts. However, the more common used of this plant was in weaving. Weavers used the cylindrical inflorescences of D. fullonum in order to roughen wool. 

*) In some literature, the Genus Dipsacus belongs to an own family: the Dipsacaceae. But in other literature, the Dipsacaceae are only a subfamily of the Caprifoliacae called Dipsacoioideae). 

Donnerstag, 11. Oktober 2012

The Caryophyllaceae - an introduction

In today's article, I want to show you the Caryophyllaceae („Nelkengewächse“ in German), which are one of the major plant families in Middle Europe. The goal of this article is to give you a general overview about this family, its systematic and the characteristic features.

1) Systematic & General Information

The family includes 86 genera with 2200 different species. Most of them are herbaceous or perennial plants, but there are also shrubs, sub-shrubs or even liana. However, the “typical” plant from the Caryophyllaceae is a herbaceous plant, which reaches heights between 50 and 100 centimeters in average.

Caryphyllaceae - flower diagram with apparent breach
of the "Rule of Alternation"

In the most cases, the leaves are narrow to lanceolate with a smooth margin. They are sitting directly at the stalk or have only a very short petiole. Usually, they are arranged in a decussate leaf-pattern. Moreover, the nodes are swollen.

However, the most distinctive feature of the Caryophyllaceae are their flowers and the inflorescences. The inflorescences are often panicles with cymes in the axillary (instead of single flowers). In Botany, such a composed inflorescence called Thyrse

Shematic construction of a thyrse

The formula of the most flowers is *K(5) C5 A5+5 G(5): five fused sepals, five free petals, two circles of stamen with five stamens per circle and five fused and epigynous carpels. But this is only the basic formula, which may very significantly (see point 2)). The Calyx is also much larger then the crown.

The stamens are also arranged in a unique way. The outer circle is inwardly offset. Thus it seems as if the stamens are breaking the Rule of Alternation, because the stamens of “outer” circle, which are in fact the stamens of the inner circle, are not alternating to the petals.

the kinked flower is typical for the Silenoideae
(here: Dianthus agg.

Primary pollinators are insects, most of them butterflies (Entomophily). For this reason, the flowers of the Caryophyllaceae are adapted to their pollinators and are designed as a large landing area. Such a flower is also called plate flower.

The ripe fruits are capsules but also berries and nuts.

All plants from the Caryophyllaceae contain Anthocyanids. This is a little bit curious, because the Caryophyllaceae belong to the order of the Caryophyllales (along with the Chenopodiaceae, Portulacaceae. Armaranthaceae) and the unique feature of this order is the content of Betalains within the plants.

betalains are characteristic for the Caryophyllales
.... but not for the Caryphyllaceae

Betalains are natural dyes (along the Anthocyanides and the Carotenoids), which are also responsible for the red color of Beetroot (Beta vulgaris). The Caryophyllaceae are one of only two families of the order without Betalains (the other family are Molluginaceae, which are native to South Africa).

2) Subfamilies and their differences

In most literature, the Caryophyllaceae are subdivided into three large subfamilies: the Silenoideae (which are the largest one), the Alsinoideae and the Paronychioideae.

  • Silenoideaa: This is the largest subfamily, which includes genera like Silene, Saponaria or Dianthus. Typical for the Silenoideae are the fused sepals of the Calyx and the kinked petals. Flower formula: *K(5) C5 A5+5 G(5)

    Silene latifolia Mill.

    Dianthus agg.

    Saponaria officinalis L.

  • Alsinoideae: The sepals of species from this subfamily are free. The petals are not kinked but deeply lobed. Thus it appears as if the flower has ten petals. Typical genera are Stellaria, Minuartia and Arenaria. Flower formula: K5 C5 A3+5 G(3)
Stellaria holostea L. - here, you can see
the depply lobed petals

Cerastium tomentosum L.
  • Paronychioideae: This is a very small subfamily with only a few genera and species (like Spergula or Hemiaria). In the most cases, the petals are missing. Another distinctive feature are stipule. Species from the Paronychioideae are the only Caryophyllaceae with stipules. Flower Formula: * K5 A5+5 G(5)

So, I hope that I was able to give you a general overview about the Caryophyllaceae. Maybe, they are not the largest or the most complex family within the vegetable kingdom, but they have some interesting features and are easy to recognize.

Dienstag, 2. Oktober 2012

Plant of the Day (October 2nd, 2012) - Saponaria officinalis L.

Today's “Plant of the Day” is Saponaria officinalis L. from the Caryophllaceae family (sub-family: Silenoideae). This species is known as “Gewöhnliches Seifenkraut” in German, while common English names are “Soapwort”, “Bouncing Bet” and “Sweet William”.

 S. officinalis. - habitus

It's a perennial plant (Hemicryptophyte), which can reach heights between 40 and 80 centimetres (15.8 to 31.5 inches). The stalk grows upright from a well branched rhizome. In the most cases, the stalk is bald but a few hairs are also possible. The leaves are lanceolate to egg-shaped and have three, distinctive leaf-veins. They are arranged in a decussate leaf-pattern.

The inflorescences are fake umbels (stalked and very dense arranged flowers; also called Dichasium in Botany). However, non-flowering stalks are also possible. The sepals are green with a red tip. The petals are red but sometimes also white (like in my pictures) and have a lobed margin. In some cases, there are also some black spots on the petals. This is a parsitic fungus, which infests the flower. Flowering time is between June and September (October). The ripe fruit is a capsule with many, black seed and opens in October.

S. officinalis - inflorescence

S, officinalis is native to Europe and Eurasia but can also be found as Neophyte in North America. It prefers fresh, nutrient-rich soils on sand or gravel, which are not to acidic and not to calcareous. So, it can be found e. g. at riverbanks, on ruderal wastelands or rocky slopes. It's a very common species in Europe but very rare in mountainous regions.

All parts of the plant (especially the rhizome) contain Saponins, which are the raw material of soap. Dissolving these plant parts in water leads to foam. So, S. officinalis was used as natural replacement for soap, what is also the reason for the name “Soapwort”. But this species is also a medicinal plant. The Sarponins also have a expectorant effect and were used to cure bronchitis and cough. However, an overdose of Sarponins leads to vomitting