Donnerstag, 30. Juni 2011

Plant of the Day (June 30th, 2011) - Mentha aquatica L.

Today's “Plant of the Day” is another swamp and quiet water plant from Lake Uemmingen in Bochum, Western Germany: Mentha aquatica L. (known as “Water Mint” in English and as “Wasserminze” or “Bachminze” in German) from the Lamiaceae family.

M. aquatica - habitus

It's a small herb (between 20 and 50 centimetres high) with an upright growing stalk and underground stolons. The leaves are egg-shaped or elliptical-shaped and have a long stalk. They're a bit of rough and polished. As with all Lamiaceae, the leaf-pattern is decussate.

As a Lamiaceae, the single parts of M. aquatica contain fragrant, essential oils. Crushed leaves of this species smell like mint with a touch of coconut.

M. aquatica - habitus

The inflorescences are whorls, but they are combined to fake-heads. Each “head” consists of many small, cygopmorphic flowers with with five white to flesh pink petals. The sepals are forming a tube with pointed ends and 13 leaf-nerves.

M. aquatica is native to Europe but can also be found in Iran, North Africa and the Caucasus. It's a swamp plant, so it grows in areas with slow flowing or quiet water, the same habitat like P. australis. Such habitats are Lakes, brooks and reeds. It prefers wet, muddy and acid soils and is part of the Phragmition australis, a typical plant society of the wetland with Phragmites australis (Cav.) Trin. ex. Steud. var. australis as characteristic species.

Dienstag, 28. Juni 2011

Plant of the Day (June 28th, 2011) - Phragmites australis (Cav.) Trin. ex. Steud. var. australis

This “Plant of the Day” comes from the Poaceae family, so it is a grass again. It's Phragmites australis (Cav.) Trin. ex. Steud. var. australis In English, this plant is known as “Common Reed” and in German as “Schilfrohr”.

P. australis - habitus

It's a very large herb; between 1 and 4 Metres (or 3,3 to 13,1 feet) high. It has many creeping stolons and a upright growing stalk. The leaf-sheath has no small cuticle (ligula), but a small tuft of hairs.

P. australis is a panicle grass, that means, its inflorescence is a panicle, which consists of many small long-stalked inflorescences, which are panicles by themself. The floral-axis of this small panicles is covered with many, long, auburn hairs. Each small panicle consists of 3 – 5 (sometimes 8) small flowers. Their lemmas has a long, knelt awn, while the upper glume is lanceolate. The whole inflorescence is very large, with a length of 60 centimetres.

The species P. australis is divided into many subspecies. One of them is Phragmites australis (Rabenh.) Conert var. pseudodonax, which is very similar to Phragmites australis (Cav.) Trin. ex. Steud. var. australis, but until 10 Metres (32,8 feet) high.

 P. australis - inflorescence

The exact origin of P. australis still unclear. Today, it is a Cosmopolit, so you can find it all over the world. It's natural habitat are the shores of very slow flowing or quiet waters like Lakes, brooks or old Bayous. It grows to one meter of water deepness, does not tolerate flooding and is also an Indicator of flowing groundwater. The Common Reed prefers muddy, fresh soils without many oxygen but with many nitrogen (eutrophic soils; typical for swamps or quiet waters).

Sonntag, 26. Juni 2011

Article of the Week - Taxonomy, Systematic and Cladistic

When you read the articles of my blog, you maybe have noticed, that Botany use many Latin names to describe species, families or genera.

So, in this “Article of the Week”, I want to talk about the basic principles of Systematic and Taxonomy. As former student, I know how difficult and confusing this topic can be, because it requires a degree of abstraction. So, let us begin with one of the basic terms: Taxon

I. The definition of the word Taxon

If you read something about systematic work, you'll certainly have heard this word before. But what is a Taxon exactly? Simply put, this word describes a position within a hierarchical system. The most important thing you have to know is, that the term of Taxon is complete free of any rank. Everything can be a Taxon, regardless of where it stands in a pedigree. So the species Sorbus aucuparia L. is a Taxon within the Rosacae, but the Rosaceae are a Taxon within the Mangnoliopsida. An elephant is a Taxon of the mammals, while the mammals are a Taxon of the vertebrates.

After the term “Taxon” is now clarified, we continue with Pedigrees.

II. Pedigree and Cladistic

A Taxon is always part of a pedigree. A pedigree is a simply method to display affinities. In the most cases, the length of its branches presents the degree of relatedness. The longer the branches, the lower is usually the relationship. Pedigrees can be generated in many different ways. In past, the main method was the comparison of morphological characters, this method was later replaced by molecular genetic methods like PCR (polymerase chain reaction) and DNA-Sequencing. But molecular genetics isn't free of making mistakes, so today a combination of classic and modern science is applied. The following picture shows a schematic pedigree.



In this simple pedigree, Taxon “C” is the least related Taxon to “D”, while B and D are the most closely related species. The Taxa “A”, “B” and “D” form a subgroup, which differs by one or more characteristics from Tacon C. Such a subgroup is also called a clade. Within cladistics (the science of pedigrees and relatives), there are different kinds of relationships. The most important ones are the following.

a) Monophyly


At the Monophyly, all Taxa originate from one common ancestor and share its features. In our example, Taxa A, B and D are a monophyletic, because all have a common stem form (arrow). Taxon C doesn't belong to this clade, because it doesn't originate from this stem form. However, if we would add a new, more basal Taxon E in our pedigree, Taxon C could be a part of this clade in relation to E. It all depends on the angle, you are looking at the pedigree.

b) Paraphyly


The paraphyly is similar to the Monophyly, but in this case, the clade includes not all Taxa. In our example, the Taxa B and D are polyphyletic towards Taxon A, because they have the same ancestor but they have grown a part. Paraphyly can be confusing, but there is a good example from Wikipedia to remember the different: The Birds and today's reptiles descend both from the dinosaurs (they are monophyletic) but today, bird are a calde by their own and the reptiles are now paraphyletic towards them.

c) Polyphyly


In a polyphletic group the single Taxa has no common ancestor but they were summarized, because they share a common character or morphological feature. In our example Taxon D and C are no related, but maybe both are able to fly, so they are summarized to a paraphyletic clade. An example for a Paraphylum are the grasses: Cyperaceae, Juncaceae and Poaceae are complete different Taxa, but they are all called grasses.

The characters, which makes a clade to a Monophylum, are called Synapomorphy, while original features are called Plesiomorphy. If a character is unique to only one Taxon, it's called Autapomorphy.


In our graphic, the Plesiomorphy is a feature, which is common to all Taxa from A to C. Maybe all of this Taxa have four legs or a spine. Now, the clade of Taxa A, D and B has milk glands, which are the Synapomorphy of this Monophylum. Finally, the Taxon B is the only Taxon with Wings, which are its unique Autapomorphy, which differs Taxon B from Taxon D.

III. Systematic


So, after I give you a overview about pedigrees and cladisitc, it's now time to take a look on the hierarchical system of Systematic. Depending on which level the Taxon stands currently, it has a different ending syllable. As an example, we consider the systematic of Sorbus aucuparia L. agg. aucuparia

Kingdom (-tae): Plantae (plants)
-Division (-phyta): Tracheophyta (vascular plants
--Subdivision (-phytina): Spermatophytina
---Class: (-opsida at plants): Mangoliopsida (Angiosperms)
---(-phyceae at alga)
---(-mycetes at fungi)
---(-lichenes at lichens)
---- Subclass (-idae): Rosidae (Rosids)
------ Order (- ales): Rosales
--------Family (-ceae): Rosaceae (Roses)
------- Subfamily (-oideae): Spiraeoideae
-------- Tribus: (-eae): Pyrae
---------- Genus: Sorbus
----------- Species: Sorbus aucparia L
------------ Sub-species: Sorbus aucuparia L. agg. aucuparia

(don't forget, that the term “Taxon” is free from any hierarchy, so Rosales is also a Taxon)

This are not all ranks, but the most important ones. Other ranks are Sub-genus, Sub-tribe or Variety. The zoological systematic follows nearby the same scheme, but has other syllables. From the stage of Genus on, all Names are written inverse (don't ask me why ;-)). In botany, the shortcut of the first-determiner is always Part of the species name. In the most cases, this Shortcut is L. and refers to the Swedish botanist Carl Linnaeus, who created this hierarchical system and the basics of Taxonomy.

Freitag, 24. Juni 2011

Plant of the Day (June 24th, 2011) - Atriplex prostrata C. D. Bouche ex. DC

Today's “Plant of the Day” is Atriplex prostrata C. D. Bouche ex. DC. or “Spear-leaved orache” in English and “Spieß-Melde in German. It belongs to the Amaranthaceae family. In past, the plant belongs to the Chenopodiacae, but recent molecular studies have shown, that this family is closely related to the Amaranthaceae, so today, the Chenopodiaceae are a sub-family of the Armanthaceae and called Chenopodioideae (in some literature, the Chenopodiaceae are still a own family).
A. prostrata is a small to medium high herb, which can reach heights between 20 and 60 centimetres. The leaves are long stalked and until 10 centimetres long. The leaf-blade is spear-shaped with a pointed end and backward curved tips. This special morphology also gave the species the name “Spear Orache”. Sometimes, the shoot axis and the leaf-stalks are covered by a mealy fluff or red overflowed.

A. prostrata - habitus

Flowers and Inflorescences are very inconspicuous and reduced, because this plant uses the wind for spreading (Anemochorie). A. prostrata is monoicous, that means, one individual has only female or male flowers. Male flowers have a small perigon (perigons also exists at the Dicotyledons); female flowers haven't any kind of a perianth but conspicuous bracts, which are 1 centimetre long and rhomboidal shaped. After pollination, this bracts are used by the ripe fruit to fly with the wind.

A. prostrata - habitus

A. prostrata is native to Europe and Western Asia. Like the most species from the genus Atriplex, this species is very tolerant toward salt, so it can be found at shorelines and even into the drift line. In the inland, A. protrata grows for example on fresh ruderal wastelands and also lake sides. It is also an indicator for the density of the soil. So places with A. prostrata are very salty or have a very dense soil.

Mittwoch, 22. Juni 2011

Plant of the Day (June 22nd, 2011) - Quercus palustris Muenchh.

Quercus palustris Münchh. is an species from the Fagaceae family. In English, this plant is known as “Spanish Swamp Oak” and in German as “Sumpfeiche”.
Q. palustris - Habitus

Like all oaks, Q. palustris is a tree, which can reach heights between 4 and 25 metres (or 13 and 82 feet). The leaves are lobed deeply. They are dark green and have a long, bald stalk, which is between 20 and 60 centimetres long. The leaves follow the alternate leaf-pattern. The bark is grey, thin and with vertical furrows.

Q. palustris - leaf

The plant is monoicous, that means, it has male and female flowers. Male flowers are located in catkin inflorescences. Female flowers are also located in catkins. They have a red stylus. The ripe fruit is a nut (acorn), which is hold by a hairy cupule.

Q. palustris - foliage

Q. palustris is native to the East of North America and can been found from Connecticut to Kansas (east → west) and Ontario to Georgia (North → South). This species prefers dry to fresh soils and grow for example in river valleys or floodplain. Despite it's name, Q. palustris is not a swamp plant. It can grow on places, which are flooded sometimes, but doesn't tolerate permanent wetness. In Europe, this plant is planted as tree in parks or lake sides sometimes. I found this individual at the shore of Lake Uemmingen in Bochum, Western Germany.

Montag, 20. Juni 2011

Article of the Week - Morphology of the grass flowers

In this “Article of the Week” (the first since two weeks) I want to give you an overview about the flower-morphology of the three great families of grasses: the Poaceae (true grasses), the Cyperaceae (sedges) and the Juncaceae (rushes). This has became necessary, after I introduced two species from the Poacae and with them, I also used some new terms, which I want to explain now.

I. Basic informations

All members of these three families belong to the Monocotyledons. The Monocotyledons are one of the two big subgroups of the Angiosperms (the other ones are the Dicotyledons). Many well known species and genera belongs to this sub-group, e. g. the Orchids (Orchidaceae), the lilies (Lilaceae) and also the grasses.

All Monocotyledons share some similarities between each other:

  • The embryos of all Monocotyledons have only one cotyledon (name)
  • (Almost) all Monocotyledons have parallel leaf-veins
  • The perianth of the Monocotyledons isn' t morphological divided into petals and sepals; there are only two circles of leaves. This type of a perianth is called Perigon and its single leaves Tepals
  • All Monocotyledons have threefold flowers (3+3 tepals, 3+3 stamen, 3 Carpels)

While the most Monocotyledons make beautiful flowers, the grasses have adapted themselves towards wind pollination and wind dispersal (Aerochorie). This leads to some changes within the morphology of their flowers and their inflorescences

II. The flowers of the Poacae

Basically, the structure of the flowers of the Poaceae corresponds to the structure of all Monocotyledons with three outer tepals, three inner tepals, three outer stamens, three inner stamens and three carpels.


However, by the time they've undergone a drastic change in their morphology. One of the outer tepals has vanished completely, the other ones has fused and became a complete new structure, which is called palea (“Vorspelze” in German). The inner tepals are reduced to small leaflets, which are called Lodiculae (Lodicula in Singular). The bract of each flower is very narrow and called lemma ("Deckspelze"). Sometimes a lemma has a long extension on their ventral side, which is known as awn ("Granne"). The bract of the whole inflorescence is called glume ("Hüllspelze").

The inner stamens have been reduced completely, and two of the three carpels are stunted.

The inflorescences is a simple raceme, but with very, very short internodes, so you think, that each of them is just a single flower. Many people often call the inflorescence of the grasses “ear” but botanically this ear is in fact a double-raceme. There are three different types of double-racemes at the Poaceae.

  • Panicle grasses: The inflorescence are sitting at the end of a long stalk. Typical Genera of this type are oat-grass (Arrhenatherum P. Beauv.), bluegrass (Poa L) or the reed canary grass (Phalaris arundinaceae L.)
  • ear grasses: At the ear grasses, the racemes are not stalked. Morphologically, this type is a double-raceme, not a real ear. Ear grasses are Barley (Hordum vulgare L.), rye (Secale cerale L.) and wheat (Triticium aestivum L)
  • Panicle-ear grasses: The inflorescences are very short stalked, so on the first sight, they may look like an ear. Grasses from this type are e. g. the foxtail (Alopecurus pratensis L.) or Timothy-grass (Phleum pratense L.)
III. The flowers of the Cyperaceae

The flowers can be the divided into two types: the flowers of the genus Carex L. and the flowers of the rest (Eriophorum L., Scirpus L., Schoenoplectus (Rchb.) Falla. and so on). While the flowers of the most genera correspond to the basic scheme of the Monocotyledons, the genus of Carex have a very unique type of flower.

At the genus of Carex, we have always pure male and female flowers, no hermaphrodites. The perigon has vanished completely, so we have no tepals. The male flowers only consists of three stamens (one circle), which is sitting in the armpit of a bract. Thereby, the male inflorescences are real ears.

The female flowers are double-ears. The fused carpels are located in the armpit of a branch, which grows from the armpit of a bract (a rudiment of this branch still exists). The bract of the flower has transformed into a tube like structure: the utriculus. Each utriculus has a small opening, where the styli of the carpels are looking out.

IV. The flowers of the Juncaceae

The flowers of the Juncaceae follows the basic scheme of the Monocotyledons overall, but their flowers are often very small and inconspicuous compared to the beautiful flowers of the lilies and orchids. In the most cases, the inflorescences are panicles or a drepanium.

V. Final Comparsion

The morphology of the flowers is not the only difference between these three families. The following chart gives you an overview about the main differences.


Poaceae
Cyperaceae
Juncaceae
shoot-axis
Round, with nodes, always hollow (except the nodes)
Triangular, without nodes, not hollow
Round, without nodes and not hollow
flower formula
P(2)+2 A3 G(3)
Male: A3; Female: G3
P3+3 A3+3 G(3) or
P3+3 A3 G(3)
fruit
One seeded nut (Karyopse)
One seeded nut
3 to many seeded capsule
inflorescences
double-racemes
double-ears
Panicle or drepanium
leaf-pattern
Alternate, in two
Alternate, in three
Alternate, in two or three
leaf-shape
Flat or rolled
Flat or rolled
Flat and ciliated

Samstag, 18. Juni 2011

Plant of the Day (June 18th, 2011) . Armoracia rusticana G. Gaertn., B. Mey & Scherb.

Armoracia rusticana G. Gaertn, B. Mey & Scherb. is a well-known plant from the Brassicaceae (aka Cruciferaceae) family. Its English name is “Horseradish” and the German name is “Meerrettich”. It's a very popular spice.

A. rusticana - Habitus

The plant is a herb, which can reach heights between 60 and 150 centimetres. The upright, bald shoot-axis is edged and hollow inside. The base leaves are very big (until 100 centimetres) and egg or lanceolate-shaped. Their edges are irregularly notched. The lower bracts are pinnate, the upper ones simple, lanceolate and have a serrated edge.

The inflorescence is an umbel-shaped raceme with four, white petals per flower. The ripe, smooth fruits (pods) are egg-shaped and between 4 and 6 millimetres long. They are located at the end of stalks, which are until 20 millimetres long.

 A. rusticana - flowers

As popular spice, Horseradish can be found all over the world (e. g. Europe, North America or even South Africa), but its true origin lays in Eastern Europe, where it was brought by the Slavic people to Middle Europe during the age of antiquity. Later it was brought from Europe to the New world.

Its natural habitats are moist or wet meadows, so you can find it for example at shore sides, lake sides or also alluvial meadows.

A. rusticana - flowers

Before the arrival of pepper, Horseradish was one of the most popular, hot spices. It contains Allylisocyanates (AITC), which give the species its pungent, sharp taste.

It was also used as medicinal plant. Because of its high content of Vitamin C, Horseradish was used against scurvy. Horseradish was also reputed to have an antibacterial effect. It was also administered in cases of poisoning, because in high doses, its sharp taste can also lead to vomiting and detoxification.

Donnerstag, 16. Juni 2011

Plants of the Day (June 16th, 2011) - Alopecurus pratensis L. & Phalaris arundinacea

Now it's time for a double-article, that means, today I will introduce two species in my “Plant of the Day” Article. The reason is simple: this two plants grow so close together, that I've made many pictures where you can see both of them, so it's easier ;)

So, today's “Plants of the Day” are Alopecurus pratensis L. and Phalaris arudinacea L. Both are grasses from the Poaceae family. A. pratensis is called “Meadow Foxtail” in English and “Wiesenfuchsschwanz” in German, while P. arundinacea is known as “Reed canary grass” in English and as “Rohrglanzgras” in German.

 A. pratensis (right) & P. arundinacea (middle)

First, I'll start with A. pratensis. This grass reaches heights until 100 centimetres and has underground stolons. The bald leaves have a rough dorsal site and a shiny ventral side. They are tapering and have a long, deeply divided Ligula.

A. pratensis - habitus

The inflorescence is a raceme. Yeah, I know, that they look like ears, but believe in me, when I say, it's a raceme. A raceme with very short inter-nodes and stalks, of course. Each flower consists of two fused glumes and two lemmas. The lemmas are much shorter then the glumes and have a short awn on their back *)

P. arundinacea reach heights until 200 centimetres. From distance, this grass looks like a reed The leaves are rough, bald and have distinct, white cross-veins. The Ligula is milky-white and a little bit ripped.

P. arundinaceae - habitus (younger plant)

Like A. pratensis, P. arundinaceae has a raceme as inflorescence, which looks like an ear. Each flower has four keeled lammas; the two outer ones are boat-shaped and and very narrow.

Both species are native to Europe and Asia, P. arundinaceae also in North America, and prefer fresh, wet and nutrient-rich places to grow (though both species can also grow on acid soils). So you can find them for example at riversides or alluvial meadows, but also on fields, where they benefit from the high fertilization.

Both types are good crops. A. pratensis is a palatable forage grass, while P. arundinacea has a energy-rich biomass so that it can be processed into pellets.

*) I know, the anatomy of grasses can be a little bit difficult, but this will be the topic of my next “Article of the week”, that I'll post Monday.. So for now don't care about words like “Ligula, awn or lemma).

Dienstag, 14. Juni 2011

Plant of the Day (June 14th, 2011) - Sorbus sorbifolia (L.) A. Braun

Hi everybody. Today's “Plant of the Day” is another neophyte. Sorbaria sorbifolia (L.) A. Braun belongs to the Rosacae. In English, this plant is called “False Spirae” and in German “Sibirische Fiederspiere”

S. sorbifolia - (faded) inflorescence

At the first sight, this plant looks very similar to Sorbus aucuparia L, which I've shown you a few days ago (in fact, this similarity has given the species its Latin Name "sorbifolia", which means "Leaves like Sorbus").

It's a medium-high shrub, which can reach heights until 2 metres (or 6,6 feet). The leaves (25 centimetres long) are unpairy-pinnate and consists of 9 to 25 small leaflets. Each leaflet is lanceolate or egg-lanceolate and has a strongly serrated edge. In contrast to S. aucuparia the leaflets are not asymmetrical at their base and end in a sharp, narrow peak. In addition, their ventral side is green and bald.

The inflorescence is a simple raceme, which is between10 to 25 centimetres long . The flowers have white petals.

S. sorbifolia - leaves

Originally, this plant is home towards Siberia, North China and Korea. It is not very demanding toward its growing places. It prefers dry, well aerated soils and dislikes wet soils with too much waterlogging. So today, you can find this species also in Europe at ruderal wastelands or in bushes, where it has escaped from gardens. 

 S. sorbifolia - here you can see the similarity but
also the differences to the leaves of S. aucuparia
(s. picture below)
 S. aucuparia - leaf

Sonntag, 12. Juni 2011

Plant of the Day (June, 12th, 2011) - Allium schoenoprasum L.

Happy Pentecost everybody. Today, I present you Allium schoenoprasum L. as today's “Plant of the Day”. This plant belongs to Amaryllidaceae. I'm sure, most of you will know this plant, because it's a very popular spice. In German, it's called “Schnittlauch” and in English “Chives”.

A. schoenoprasum - habitus

It's a small herb, with heights between 20 and 20 centimetres. The leaves are very narrow and stalk-like shaped with a hollow interior. Without its inflorescences, the plant looks like a grass.

The inflorescences follow the “head 2” pattern. Each head consists of 30 – 50 small flowers with six pink or purple tepals per flower. The ripe fruits are black capsules.

 A. schoenoprasum - inflorescences

The true origin of A. schoenoprasum is unkown. Some Scientists think, that it came from Central Asia or the Mediterranean Basin. Others say, that it was native to the Alps. Anyway, today you can find this species all over the World, especially in Europe, Asia and Northern America. Natural populations grow in the mountainous regions on rocky slopes but also at river sides. It prefers loose, wet and nutrient-rich soils.

A. schoenoprasum - single inflorescence
(here you can see a single flower from above)

Because of its tangy taste, A. schoenoprasum, has become a very popular spice, especially as part of the French and Mediterranean “Fines Herbes” cuisine. Anthropologists believe, that chives was grown as spice since the middle age. So today, you can find this species also outside of their natural habitat in gardens and so on. Sometimes, some individuals also grow wild.

Freitag, 10. Juni 2011

Plant of the Day (June 10th, 2011) - Matteuccia struthiopteris (L.) Tod.

After a long time, I want to present you a fern again. This fern is Matteuccia struthiopteris (L.) Tod. from the Onocleaceae. It one of only two species of the Genus Matteuccia. In English, the fern is called “Ostrich fern” or “shuttlecock fern”, while in German, we called it “Straußenfarn”.

 M. struthiopteris - habitus (sterile fronds)

Normally this fern reaches heights between 50 and 170 centimetres. It's sterile fronds grow in a funnel-shaped rosette. They are bright-green and wide laceolate. Each frond is strongly narrowed to the base. The lower leaflets are curved around the Rachys.

 M. struthiopteris - habitus (sterile fronds)

The fertile fronds are located in the centre of the rosette; surrounded by the sterile fronds. They are brown, smaller and look like the feathers of an ostrich, what gave the species also it's name. The sporangia (Sori) are sitting in two rows on the ventral side of the fronds.

M. struthiopteris - sterile frond. Here, you can see
the curved leaflets (arrows)

M. struthiopteris is widespread all over the northern hemisphere (circumpolar distribution). It prefers wet, sandy soils, which are rich of nutrients. So, you can find it for example at lakesides, floodplains or small rivers. I found this one at the lakeside of Lake “Ümmingen” in Bochum, Western Germay.

 M. struthiopteris - sterile frond

Mittwoch, 8. Juni 2011

Plant of the Day (June 8th, 2011) - Digitalis purpurea L.

So, today's “Plant of the Day” is Digitalis purpurea L; the “Purple Foxglove” or in German “Roter Fingerhut. This species is from the genus Digitalis of the Plantaginaceae family. In old literature, this plant still belongs to the Scrophulariaceae.

D. pupurea - habitus

It's a tall plant with heights between 50 and 120 centimetres. The leaves are located into a rosette. Each leaf is laceolate with a simple edge. The ventral side is felty and grey, the upper side is bright-green with raised field. The shoot-axis is also felty.

 D. pupurea - leaves (garden breed)

D. purpurea - leaves (wild form)

However, the most distinctive character of Digitalis purpurea L. is its inflorescence. It's a simple raceme, which consists of many cygomorphic flowers. Each flower has five purple petals, which are fused together to a long tube. The green sepals are free and form a small goblet. Another conspicuous character of this species are the white spots with a black core on the inside of the bottom petals. Some individuals have white petals (especially breeds).

Originally, D. purpurea is native to Europe but also to Morocco. It can also be found in North- and South America as Neophyte. The species prefers acid soils and sunny to semi-bright places to grow. So you can find it for example at woodcutting areas, clearings or waysides, which are its natural habitats. But because of its beautiful flowers, it's also a very popular garden plant. I've found also some indivudals at ruderal places.

D. purpurea - flowers

Digitalis purpurea L. is a very toxic plant. This species has its name from the chemicals Digitoxin and Digoxin. Both are very effective cardiac glycosides, which can cause both a acceleration or a slowdown of the heart rate. So, the ingredients of Digitalis may cause a deadly heart attack, if you eat flowers or leaves. On the other Hand, the ingredients are also used to make medicaments against heart failure.

D. purpurea - inflorescense

D. purpurea is also a mythological significance, especially in Ireland. Celtic people believes, that the tubular flowers were used as hat by elves. They also believed, that evil elves gave the flowers to foxes for their feet, so they could plunder the chicken coops silently. This legend gave the species also its English name.

Montag, 6. Juni 2011

Plant of the Day (June 6th, 2011) - Sorbus aucuparia L. ssp. aucuparia

Sorry folks, but this week, there' ll be no “Article of the Week”, because I was out and have no time for a “big” article (and it was also too hot for me -.-). So today, I only want to show you a new and very interesting plant: Sorbus aucuparia L. ssp. aucuparia from the Rosaceae family. In English, this species is known as “European Mountain Ash” or “Rowan”, in German as “Eberesche” or “Vogelbeere”

 S. aucpuaria - habitus

It's a tall shrub with heights between 3 and 15 metres (9,8 to 49,2 feet). The leaves are unpaired-pinnate. The leaflets are lanceolate to elliptical shaped and has a furrowed edge. They are asymmetrical at the base, which is a good character to identify this species. Their dorsal side is dark-green; the ventral side grey-green. In autumn, the leaflets change their colour into a very beautiful deep-red or golden-yellow. All leaves also have stipules.

The inflorescences are umbel-shaped racemes (it's not a real umbel!). Each raceme consists of many small, single flowers (sometimes 200 or 300 flowers per raceme!). A single flowers is radial and has five green sepals and five white petals. Like the most Rosaceae, S. aucuparia has many stamens.

S. aucuparia - leaf (note the asymmetrical base
of the leaflets)

The ripe fruits are distinctive red. The may look like berries, but in fact, it's same fruit type as in Malus domesticus Borkh. (a hard core, which is enclosed by the fleshy bottom of the flower). They are eaten by birds, which spread out the seed by their excrements. This type of spreading is called Ornithochorie. They are not toxic, but uneatable, very sour and can cause a laxative effect, because of the high content of sorbic acid. Anyway, the fruits of some garden forms are edible and used to make jam.

S. aucuparia - inflorescences (unfortunately faded)

S. aucuparia is native to Europe and Western Asia. It is a very popular garden and park tree but grows also for example on ruderal wastelands (I found this at the same old, abandoned train tracks, I've found Robinia pseudoacacia L) It's a very flexible plant, that can grow on almost every soil (acid, alkaline, nitrogen-rich, nitrogen-poor and so on).

The Rowan plays also a big role in mythology. For example, this species was the holy tree of the god Thor.

Hmm, this “Plant of the Day” Article has become very extensive, hasn't it? So I think, it was a good excuse for the failed “Article of the Week” :D

Samstag, 4. Juni 2011

Plant of the Day (June 4th, 2011) - Anthriscus sylvestris (L.) Hoffm. ssp. sylvestris

Anthriscus sylvestris (L.) Hoffm. ssp. sylvestris belongs to the Apiaceae family (also known as Umbeliferaceae in some literature). In English, the plant is called “Keck”, “Wild Chervil” or “Wild Beaked Parsley” and in German “Wiesenkerbel”.

 A. sylvestris - inflorescences

It's a medium high herb, which can reach heights between 60 and 150 centimetres. The shoot-axis is sharp-furrowed with protruding rips. The foliage-leaves are double or triple pinnate. Interestingly, the bottom pair of leaflets is shorter than the rest of the leaflets. Each leaflet is lanceolate to egg-lanceolate and in turn strongly pinnate. 

A. sylvestris - here you can see, that the bottom
pair of leaflets is smaller than remaining leaflets

The inflorescence of A. sylvestris is a double-umbel. (Umbels or double umbels are a key character of the Apiaceae). Each double umbel consists of about five small umbels. Each umbel in turn consists of between 8 and 15 flowers. The flowers have five white petals; the sepals are reduced and are not often seen. The central flowers are radial, the marginal flowers are cygomorph.

A. sylvestris - here you can see the
furrowed shoot.axis with its rips

A. sylvestis is native to the Old World, especially to Middle Europe, Western Asia and North Africa. It prefers nitrogen-rich soil and sunny to semi-shadowed places. So you can find it e. g. at pastures, meadows or bushes. It isn't toxic but nevertheless unpopular with farmers, because the hard, sharp stems are inedible for the cattle.