Donnerstag, 29. September 2011

September 29th, 2009 - Supplement to Fallopia japonica (Houtt.) Ronse Decr.

Hi everybody,

in my posting about Fallopia japonica (Houtt.) Ronse Decr. (Japanes knotweed) from July 19th, 2011, I didn't show you any pictures of the inflorescences, because the flowering time of this plant starts within August. Meanwhile I've found many individuals with flowers, so I've some pictures of the panicles, but don't ask me, if these are male or female flowers.

F. japonica - inflorescenes

If you remember, I also mentioned, that F. japonica is a very problematic plant, because it's an aggressive invasor, which can overgrown places very fast. I showed you a picture of a stock, but this was not very impressive. But now, I've a very imposing picture for you.

F. japonica - stock

Yo, this is all F. japonica. This stock grows next to a train station in Solingen, Western Germany. Now you can see, how fast this plant can spread; just compare the size of the stock with the platform of the station.

Freitag, 23. September 2011

Plant of the Day /(September 23th, 2011) - Melissa officinalis L. (ssp. officinalis)

Today's “Plant of the Day” is Melissa officinalis L., known as “Lemon balm” in English and as “Zitronenmelisse” in German. It's a species from the Lamiaceae family; the family with the characteristic lip-shaped flowers, of which I've shown some species before.

M. officinalis - habitus

It's a herb, which can reach heights between 20 and 80 centimetres. The stem is square (as with all Lamiaceae), richly branched but only slightly hairy. Many of these hairs are glands. As with all plants of the Lamiaceae, the leaves are decussate. They've a stalk, which is between 1 and 3,5 centimetres long and have an egg-shaped to rhomboidal leaf-blade with rough sawn edges. Each plant has also short, underground stolons.

M. officinalis  - leaf

Both, leaves and stem, smell like lemon, if you crush them between your fingers.

The inflorescences are small whorls with normally four to six (sometimes twelve) flowers per inflorescence. Theses flowers are very small (only 1 to 1,5 centimetres long), with green sepals and cream petals. As with all Lamiaceae, the petals are fused to an upper lip and a lower lip.

M. officinalis - flowers & leaves

Originally, this plant is native to the Eastern Mediterranean Areas like Turkey, Iraq, Iran or Pakistan, but as very popular spice plant, you can find it also in many other regions of the world like Middle Europe in e. g. gardens but also clearings and forests. It prefers warm, dry places with humus- and nutrient-rich soils on sand or clay.

M. officinalis - flowers & leaves

Because of its lemon fragrance, M. officinalis is a very popular spice plant, which is used for salad dressings, teas or liqueurs but also as drug in some cases.

Montag, 19. September 2011

Plant of the Day (September 19th, 2011) - Acer pseudoplatanus L.

This time I've a new tree for you. It's Acer pseudoplatanus L. from the Sapindaceae family. In English, this plant is known as “Sycamore” or “Sycamore Maple”, while in German it's called “Berg-Ahorn (Mountain Acer). The Latin name “pseudoplatanus” refers to the similarity of the leaves towards the leaves of the American plane (Platanus occidentalis L.).
A. pseudoplatanus - habitus

It a big tree, which can reach heights between 8 and 30 metres (26.2 feet to 98.4 feet). The bark is smooth, but individual pieces fall from the tree like scales. The leaves are the typical five-lobed, digitate maple leaves, with an irregularly notched or serreated edge. They've a dark green dorsal site and a bright green ventral site. The leaves follows the opposite leaf-pattern with two leaves per node. They also have a long stalk, which is green or sometimes red.

A. pseudplatanus - leaves

A. pseudoplatanus - leaf

The inflorescences are hanging panicles. The monoicous flowers are yellow or yellowish green. Typical for this tree are its winged, ripe fruits, which fly with the wind like a helicopter. This kind of dispersal is called Pterometeorochory

A. pseudoplatanus - fruits

A. pseudoplatanus is native to Europe and Asia. It's the most common species of the Genus Acer in Europe. It's a fast growing, undemanding tree, that can grow on slopes, ruderal wasteland or regosols. This makes A. pseudoplatanus an important pioneer plant. Its fallen leaves rot quickly and produce a good humus, which can be used by other plants. Its deep, straight root loosens also hard soils. This species benefits also from human influence. The man spreads the kind on places, where it can grow without the pressure of higher competitive species (e. g. in cities, parks or forests).

A. pseudoplatanus - bark

Freitag, 16. September 2011

Plant of the Day (September 16th, 2011) - Aegopodium podagraria L.

Today's “Plant of the Day” is probably one of the most unpopular herbs for gardeners. It's Aegopodium podagraria L. from the Apiacae (or Umbelliferaceae) family. In English, this plant is best known as “Ground elder”, while in Germany it has many names like “Geißfuß” “Ziegenfuß (goat foot)” or “Dreiblatt (three leaves)” but the most common name for this plant in my homeland is “Giersch”.
A. podagraria - habitus

It's a herb, that can reach heights until 1 metre (or 3,3 feet). The stalk is bald and furrowed, while the leaves are pinnate and divided into 2 or 3 small leaflets. Each leaflet is oval to egg-shaped with a fine serrated leaf-edge. The plant is known for its underground stolons, that makes the plant to a persistent weed, which is very difficult to control.

A. podagraria - leaf

The inflorescence is an umbel, which is typical for the Apiaceae (remember, that each “umbel” is in fact a double-umbel). Each umbel consists of 15 to 25 small umbels. As with most Apiacae, the flowers of A. podagraria has white petals, while the ripe fruits are egg-shaped.

A. podagraria - umbel

A. podagraria is the only species of the genus Aegopodium, that is native to Middle Europe, but you can also find it in North America as neophyte. It likes nutrient-rich soils and shady places. As already mentioned, it's a very persistent weed, because of its stolons. Through this, the plant is able to cover large areas. On the other side, A. podagraria is also used as spice plant in the kitchen and even as medicinal plant against gout and rheumatism.

 A. podagraria - umbels

 A. podagraria - leaves

Montag, 12. September 2011

Plant of the Day (September 12th, 2011) - Linaria vulgaris Mill.

This time, I want to show you Linaria vulgaris Mill. In German this plant is known as “Gewöhnliches Leinkraut”, “Frauenflachs” or “Kleines Löwenmaul”, while in English, you may known it as “Common Toadflax”. The membership of this plant is a little bit unclear. Previously, it belongs to the Scrophulariaceae, but today, many author put it into the Plantaginaceae family. Anyway, in many books, L. vulgaris still belongs to the Scrophulariaceae. Therefore, I'll accept both versions to avoid confusion.

L. vulgaris - habitus

This plant is a herb, which can reach heights between 20 and 40 centimetres. It has a simple, round shoot-axis, which is covered with glands in its upper section, while the lower area is bare. The thin leaves are narrow and laneceolate with three leaf-veins per leaf. They are between 2 and 5 centimetres long and are sitting directly on the shoot-axis.

L. vulgaris - leaf

The flowers are cygomorph with five free sepals and five fused petals with a stirking bulge on the anterior petal. The sense of the bulge is in then nature of pollination. L. vulgaris is specialized in large pollinators like bumblebees. Only this pollinators are strong enough to push down the bulge to reach the nectar. The petals are yellowish, while the bulge is deep yellow or orange. The sepals are green. Furthermore, each flower has a long, yellow spur, which is an outgrowth of the petals.
The fruit is a capsule, which matures between July and September.

L. vulgaris - flowers

The species is native to Europe and Asia, but also a neophyte in North America. It's also a so called Apophyte. An Apophyte is a plant, which has become completely dependent on the anthropogenic influence. It grows on warm, rocky soils and open, bright places. So, it benefits from human influence, because man creates exactly the right habitats in the form of embankments, slopes or industrial wasteland.

Sonntag, 4. September 2011

Plant of the Day (September 4th, 2011) - Juncus compressus Jacq.

Today's plant is a small grass from the Junaceae (rush) family. Its name is Juncus compressus Jacq.; in English known as “Round-fruited Rush” and in German as “Platthalm-Binse”.

J. compressus - habitus

It's small plant with heights between 15 and 30 centimetres. The upright growing stalk is compressed, what gave the plant also its name. Each plant has one or two foliage leaves. These leaves are grey-green, ply and have a shiny leaf-blade. They've also auricles at the base.

The flowers are small, inconspicuous perigones with six, brown or reddish tepals. They are between 2 or 3 millimetres long and have a blunt end. Each flower is topped by a very long bract.

J. compressus - flowers
b = bract; f = fruit; p = perigone
s = shoot

This small plant is native to Europe and Asia but can also found as neophyte in North America. J. compressus grow primary on crushed, dense soils, so you can find it e. g. on trails, sidewalks or trampled meadows. I found this one on a pavement in the middle of my hometown. It grows on sandy or loamy soils but also on lime.