Montag, 23. Dezember 2013

Montag, 16. Dezember 2013

Plant of the Day (Dezember 17th, 2013) - Euphorbia pulcherrima Wild. ex. Klotsch.

Christmas is coming and so, I decided to dedicate the Post of this week one of the most popular Christmas plants. No, I'm not speaking off a Christmas tree (however, you can find my article about Abies nordmannia,the popular Christmas tree, here), but off Euphorbia pulcherrima Willd. ex. Klotsch. from the Euphorbiaceae family. In German, this species is known as “Weihnachtsstern” (Christmas's Star). In English, the species is known as Poinsettia; named after the U. S. diplomat (and later Secretary of Defense) Joel Roberts Poinsett, who introduced the species in North America in 1825.

1) Description

First of all, it's important to differ between the natural Poinsettia and the ornamental plant. The natural form is a perennial plant or evergreen shrub, which can reach heights between 90 centimeters and 3 meters (3.0 to 10.0 feet). It grows very sweeping and is one of the most sweeping Euphorbia species. However, the stalk isn't so richly branched and the internodes are very long. In contrast to this, the internodes of the breedings are shorter and the stalk is richly branched to create a dense foliage. These sorts are also smaller.

E. pulcherrima - habitus (breeding)

In both cases, the leaf bases are lanceolate to oval. They are sitting at the end of a long petiole, which is about 8 centimeters (3 inches) long. Their margin is smooth to slightly serrated. The dorsal site has a dark green color with white leaf-veins as contrast, while the ventral site is more bright green.

E. pulcherrima - leaf

As with the most Euphorbiaceae, the inflorescence of E. pulcherrima is a Cyanthium; a large, fake “flower”, which is composed of many small flowers and bracts. In this case, the actual flowers are very inconspicuous. They are small an have a yellow to yellowish green color. Petals and sepals are missing completely. Flower are either male or female. In the most cases, the flower in the center is female, while the other flowers are male (indicated by the single stamen). There are also some lip-shaped glands at the edge of each Cyanthium. They secrete nectar to attract pollinators.

E. pulcherrima - leaf veins

So, the main attraction is made by the conspicuous bracts, which surround the flowers. Basically, they have the same shape like the normal leaves but the have a bright, red color, which creates a strong contrast towards the rest of the plant. In cultivation, other colors like pink or cream-white are also popular. Blue bracts aren't naturally. In this case, the bracts are over painted with a varnish.

 E. pulcherrima - bract

Flowering time is between November and February. E. pulcherrima is a short-day plant. That means, the bracts only become red, if they aren't exposed to sunlight more than 12 hours. So, it prefers shady places to grow (see distribution).

E. pulcherrima - Cyanthium with  1) stamens, 2) female flowers
and 3) glands

All parts of E. pulcherrima contain a milky, white juice, which is typical for the most (but not for all) Euphorbiaceae. This juice is a little bit toxic and can cause skin irritations and allergic reactions. However, the plant isn't deadly poisonous like some people say.

2) Distribution

E. pulcherrima is native to Mexico and Middle America. However, it can also be found as Neophyte in Africa and the Mediterranean. The plant prefers a warm to hot climate and grows in the undergrowth of the forests with long, warm summers. It likes shady places on a moist but not wet soil. The plant is very sensitive towards light and temperature and will wilt, if it becomes to cold.

Today, the poinsettia is one of the most popular ornamental plants of the world. It was introduced to the United States by Joel Roberts Poinsett in 1825 and in Europe by Alexander von Humboldt in 1804. Since then, many different sorts and breedings were created. The plant is very popular for Christmas-themed floral displays, because the flowering time (more accurate: Dyeing of the bracts) happens during the winter months. In addition, the arrangement of the bracts reminds at the Star of Bethlehem.

Freitag, 6. Dezember 2013

Plant of the Day (December 6th, 2013) - Lepidium latifolium L.

Pfefferkraut” (what is the literally translation of “Pepperwort”). However, there is also another plant, Satureja hortensis from the Lamiaceae, which is also known as “Pfefferkraut”. So, it's always an advantage, if you know the Latin name.

1) Description

Our species is a perennial plant, what is remarkable, because the most species from the genus Lepidium are annual or biennial plants. L. latifolium is also one of the largest plants from the Genus, because it can reach heights between 50 and 130 centimeter. It has also a widely branched rhizome. As a result, our “Pepperwort” grows in dense stocks as shrub.

L. latifolium  - habitus; on the right side,
you can also see a basal leaf with its petiole

The basal leaves are about 25 centimeters long. They are lanceolate to egg-shaped and have a long petiole. In contrast to this the upper leaves and stalks have no petiole, but sit directly on the stem. They are also smaller (between 5 and 10 centimeters in length) and more lanceolate as egg-shaped.

 L. latifolium - habitus; here, you can see flowers an 
the leaves
Another difference to other species from the Genus Lepidium are the inflorescences. While the inflorescences of the most species from this genus are dense racemes, the inflorescence of L. latifolium is a loose, width pancicle, which consists of many, small flowers. Each flower has white to cream-white petals, which are only about 2,5 millimeters long. The pods (Schote) are elliptical to round and about 2 millimeters in diameter.

L. latifolium - leaves (basal and upper leaves)

Like the most Lepidium species, L. latifolium can be used as vegetable and spice. The leaves have a intense, sharp taste, which is even stronger than the taste of the more common “garden cress” (L. sativum).

2) Distribution

L. sativum is native to Eurasia but can also be found in North America as a neophyte. In this regions, the plant is even an invasive species, which threatens Biotopes like salt marches and flood plains by its rapid spreading.
flood plains like this are a good habitus for L. latifolium
beyond the shores.

It's a salt plant, which grows on salty places on sand and clay. So, it can normally been found along the shores at beaches and dunes. In the Inland, it's rare but can also be found at flood plains or other salty places like some ruderal wastelands. We found this exemplar at the shores of the river Rhine in Duisburg-Homberg during a field trip in August 2013.

Freitag, 22. November 2013

Species of the Day (November 22nd, 2013) - Chlorophyllum brunneum (Farlow & Burt) Vellinga

This week, I want to present another mushroom. So, the actual “Species of the day” is Chlorophyllum brunneum (Farlow & Burt) Vellinga from the Agaricaceae family. In German, this species is known as “Garten-Safranschirmling” and in English as “Shaggy Parasol”.

However, the actual taxonomy of the Genus Chlorophyllum (“Safranschirmlinge” in German) was unclear for a long time. Earlier, C. brunneum and Chlorophyllum rachodes (Vittad.) Vellinga were the same species, which was called Macrolepiota rachodes. Because the taxonomy of the Genus Chlorophyllum is still new, you can find three different names for the species in literature: Chlorophyllum brunneum (the newest), Chlorophyllum rachodes (which is another species) and Macrolepiota rachodes. This sounds confusing, but I hope, that my picture will make it clear for you.

Different Systematics of the Genus Chlorophyllum
(please note: this is not a phylogenetic cladogram; it serves only
for illustration)

1) Description

C. brunneum is a large fungus, whose mushroom can reach between 18 and 20 centimeters (7 to 8 inches) in diameter. The surface of the mushroom is covered with loose, white scales, which give the mushroom a tattered habitus. The scales are arranged in concentric circles, but the arrangement isn't so clear as with the real Parasol (Macropiota procera). There is a large cap in the center of the mushroom, which has a more or less intense, maroon color.

C. brunneum - habitus

The stalk reaches an average length of nearly 15 centimeters (6 inches). It's nearly smooth and featureless, but if hurt, the stalk "bleeds" in red or orange, what is also the reason for the German name “Safranschirmling” (“Safran” is German for Saffron, a red to orange colored spice). The base of the stalk is lumpy thickened, what is also the main difference to C. rachodes (another one is the maroon cap; C. rachodes has a small, inconspicuous cap only).

C. brunneum - on this picture, you
can see the lumpy thickened base of the stalk

There's nothing special about the gills. They are cream-white like the rest of the fungus. However, there are also some darker spots at the points of pressure (e. g. at the edge of the mushroom). This phenomenon is also a result of the reddish fluid within the fungus.

C. brunneum - the mushroom with its
maroon cap and the cream white flakes

C. brunneum is a little bit toxic. It isn't deadly, but consumption may lead to some uncomfortable complaints. However, the similar C. rachodes is edible, if cooked. On the other side, there is also another species of this Genus, Chlorophyllum venenatum, which is toxic. In this case, consumption leads to strong gastro-intestinal complaints. C. venenatum looks almost exactly like C. brunneum (there are only microscopic differences between the hyphae). and can be confused easily with it. So, be careful, if you want to collect fungi from this Genus (Though, C. venneatum is rare in Middle Europe and more common in Southern Europe).

2) Distribution

The shaggy parasol is native to Europe. Unlike C. rachodes, which grows in the woods, our species can also be found in parks, roadsides and in gardens, because it prefers a very nutrient-rich soil and such a soil is often man-made. This makes C. brunneum to a typical profiteer of anthropogenic influence.

Mittwoch, 13. November 2013

Species of the Day (November 13th, 2013) - Lepiota aspera Pers. (Fr.) Quel. (also Echinoderma asperum (Pers.) M. Bon.

After a longer break, it's now time for a new Post. However, today's “Plant of the Day” is actually a fungus. This fungus is Lepiota aspera (Pers. Fr.) Quel. from the Agaricaceae family. Other names are Echinoderma aspera or Lepiota frisii. In German, the species is known as “Spitzschuppiger Schirmling”, while the common English name is “Frackled Depperling”.

1) Description

L. aspera is a larger fungi, whose mushroom can reach an average high of nearly 15 centimeters. The cap is conical at the beginning, but folds up later and becomes more umbrella-like. However, the most distinctive feature of this species is the surface of the cap, which is covered with many, maroon scales on a bright ground of ochre. These scales are also responsible for the German name “Spitzschuppig” (literally: “spiky scales”). Because the surface of the cap looks dismembered, the scales are also the reason name for the English name. All in all, L. aspera is easy to recognize, even by laymen.

L. aspera  - cap with scales

The gills (“lamellen” in German”) are close together and are often branched. Otherwise, they are inconspicuous with a pale color and some fine hairs along the edges. The stalk is also pale but the lower regions are covered with some scales like the cap. The annulus (the ring in the middle of the stalk) has a bright brown color with a darker margin; the base of the stalk is thickened.

L. aspera - habitus

L. aspera isn't edible, because the fungus is a little bit toxic. The consumption would lead to some complaints, which aren't deadly but uncomfortable. In the most cases, the consumption is prevented by the sour, unappetizing smell of the flesh.

2) Distribution

L. aspera is a very common fungus, which can be found in the temperate or oceanic regions of the world. It prefers a nutrient-rich soil and is even an indicator for nitrogen. It grows in forests, gardens and even in hedges and parks under shrubs and trees. The species lives often in a community with Urtica dioica (nettle), because the nettle is also a classic indicator for nitrogen within the soil.

Mittwoch, 23. Oktober 2013

Plant of the Day (October 23rd, 2013) - Corydalis lutea (L.) DC. (aka Psuedofumaria lutea (L.) Borkh.)

Today's “Plant of the Day” is Corydalis lutea (L.) DC.; a species from the the Papaverceae, whose namesake is the poppy (Genus: Papaver). The German name for this species is “Gelber Lerchensporn”, while the common English name is “Yellow Corydalis”, what is the literal translation of the species name (“lutea” is the Latin word for “yellow”).

Please note: in some literature, the species is also known as Pseudofurmaria lutea (L.) Borkh. And belongs to the Fumariaceae.

1) Description

C. lutea is a smaller perennial plant, which can reach an average maximum height of nearly 30 centimeters (12 inches). The stalks are very thin. However, there are multiple stalks, which are also richly branched. As a result, the plant can grow in dense stocks. All stalks of the plant are bald.

C. lutea - habitus

The leaves have a complex habitus, because they are double to tripple pinnate. Each leaf consists of of nearly three to five leaflets (however, the actual number may vary from leaf to leaf). To make it even more complicated, the leaflets are digitate with a lobbed margin and have a wedge-shaped ground. The dorsal site of each leaflet is bright green, while the ventral site is greyish-green. Stipules are missing, but the bracts are very narrow and not pinnate, so they might look like stipules.

C. lutea - leave (and leaflets)

The inflorescences of C. lutea are racemes with many flowers. These flowers are cygomorphic and consists of four petals and sepals. Both, sepals and petals, have a golden yellow color (hence the name “lutea”). The sepals are a little bit longer than the petals and form a characteristic extension: the Spur (“Sporn” in German).

C. lutea - flowers with spur (red Circle)

Flowering time is between May and October. The primary pollinators are insects, which land on the flower and open the perianth tube by their weight. The ripe fruits are green silques, which contain many small, black seeds.

2) Distribution

C. lutea is native to the Alpine Regions of southern Europe (like Italy or Switzerland), where it grows between lime rocks. By the time, the plant spread across Europe and was imported to North America as ornamental plant.

C. lutea - silques

As a result, the species can be found in many temperate regions of the world today. C. lutea grows on walls, which are similar to its natural habitat. So, it has become very common in cities

Dienstag, 15. Oktober 2013

Plants of the Day (October 16th, 2013) - Chenopodium album L. and Chenopodium glaucum L. (aka Oxybasis glaucum (L.) S. Fuentes, Uotila & Borsch.)

After a longer break, it's time for a new Posting. Today, I want to show you two species at once, because both plants are very similar for laymen. This species are Chenopodium glaucum L. and Chenopodium album L. Both species are member of the Amaranthaceae.

C. album - habitus

In German, the first species is known as “Graugrüner Gänsefuß” and the second species as “Weißer Gänsefuß” or “Ackermelde”. The common English name of C. glaucum is “Oak-leafed goosefoot” while C. album is known as “White Goosefoot”, “Melde” or “pigweed”.

1) Description

Both species are annual herbs. C. glaucum is highly variable in its length, which can be between 5 and (rarely) 120 centimeters (usually around 40 centimeters). However, the stalk doesn't grow straight upright but creeps over the ground, so the plant isn't very high. C. album grows upright and as a result, the species reaches heights between 15 and 180 centimeters but a maximum height over 250 centimeters is also possible. The stalk is stripped green but becomes red during autumn. The whole plant is covered with a floury white fluff, which gives it a white to greyish color. This is also the reason for the name C. album (“album” means “white”). The stalk of C. glaucum hasn't such distinctive features.

C. album - leaves and the stalk

The leaves of C. glaucum are oak-shaped with a deeply lobbed or serrated margin. Their ventral site is floury white, while the dorsal site is blueish green, what is the reason for the name of the species (“Glaucum” means “blueish”). Another distinctive feature is the white leaf-vein on the dorsal site. The leaves are also a little bit fleshy.

you can see some distinctive features of C. glaucumon this picture
(e. g. the leaf vein, the blueish green dorsal site, the white ventral
site and the creeping habitus)

The leaves of C. glaucum are highly variable in form and shape. They can be egg-shaped, laceolate or even rhomboid. This may vary from plant to plant. The same applies for the margin, which can be lobbed, roughly serrated or even smooth. However, the bracts are more narrow and often has a smooth margin.

C. album - inflorescene; you can also see the narrow

In both cases, the inflorescences are panicles, but the panicles of C. glaucum is larger and more pyramidal. Both species have very inconspicuous flowers with small, green to greyish petals and sepals. Wind is the primary pollinator and distributor, what is also a reason for this small flowers (they don't need large flowers to attract pollinators like bees or flies). Flowering time is between June and October.

2) Distribution

Both species are native to the norther hemisphere and can be found in Eurasia and North America (here as a Neophyte). The true origin of both species is unknown, but botanists believe, that both species are native to Asia, where they spread out to Europe as Archaeophytes in Accident times. From Europe, seeds of both species came to North America with ships.

C. album - stalk; you can see the stripes and the
red color of older parts.

C. glaucum and C. album are typical pioneers on ruderal wastelands and similar places. They aren't very demanding and can grow on many soils, which are unfavorable to other plants. Plant societies with species of the Genus Chenopodium are typical for rough grounds, ruderal wastelands and dumps.

Please note: current researches found out, that C. glaucum doesn't belong to the Genus Chenopodium. Today, it belongs to the Genus Oxbyasis and is known as Oxybasis glaucum (L.) S. Fuentes, Uotila & Borsch. However, I will use the old nomenclature, because it's more widespread in the literature.

Freitag, 4. Oktober 2013

Plant of the Day (October 5th, 2013) - Galium album Mill.

This week, we take a closer look at Galium album Mill.; a species from the Rubiaceae family. In German, this species is known as “Weißes Labkraut”, while the common English names is “White Bedstraw”. The species is closely related with Galium odoratum (L.) Scop. (“woodruff” in English; “Waldmeister” in German)

1) Description

G. album is a perennial plant, which can reach heights between 25 and 80 centimeters. The quadrangular stalk grows from creeping to upright. In the most cases, the whole plant is bald but sometimes, some bristles along the stalk are also possible (see below)

G. album - on a meadow

It's also a Hemikryptophyte. If you remember my Article about life-forms, you know that a Hemikryptophyte is a plant, which growing buds are laying on the ground and are protected by leaves or creeping shoots.

G. album - inflorescence; (f) = Fruit; (p) = petals

The leaves are arranged in whorls with 6 to 8 leaves per node. Both sides are green and all leaves are lanceolate and narrowed to their tips. They have an average width of nearly 3 to 4 centimeters and are at least twice as long as wide (but often much longer).

 G. album - habitus

The inflorescences are loose panicles with small flowers. Each flower is nearly 5 millimeters in diameter and consists of four small, green sepals and four, white petals. Flowering time is between June and September. The ripe fruits are dry and disintegrates into two sub-fruits.

2) Distribution

G. album is native to temperate, oceanic regions of Eurasia. It prefers fresh places on a nutrient-rich soil, but tolerates also dryness. The plant grows on pastures, meadows but also on ruderal wastelands and belong roadsides. As a result, the species is part of many different plant societies on meadows.

such a meadow is an example for a typical 
habitat of G. album

There is also a sub-species of this plant, which is called Gallium album ssp pycnotrichum. It's similar to G. album ssp. album, (the main species, which I've described above) but in this case, the whole plant is covered with hairs. In older literature, this sub-species is still an own species: Gallium pcynotrichum.

Montag, 23. September 2013

Plant of the Day (23rd September, 2013) - Datura stramonium L.

The next “Plant of the Day” is Datura stramonium L.; a species from the Solanaceae family. The common German name of this plant is “Gemeiner Stechapfel”. In English, the plant is known as “Jimson weed” or simply “Datura”.

1) Description

D. stramonium - habitus

D. stramonium is an annual plant, which reaches heights between 30 and 120 centimeters. The bald, strong stalk is hollow and fork-like branched (two branches per node). The leaves are egg-shaped and have a long petiole. Their margin is irregular lobated and the ground of the leaf blade is a little bit wedge-shaped. There are no stipules. 

D. stramonium - leaf
The flowers are in the axils of the branches with one flower per axil. They are trumpet-like shaped and have five sepals and five petals. The bright-green sepals are fused and form a five angular tube. The petals are white and funnel shaped. An interesting feature is the flowering, because the flowers are closed at day and open at night. The reason for this is, that the primary pollinators of D. stramonium are moths, which are nocturnal. Flowering time is between June and October.

D. stramonium - flowers

However, the most distinctive feature of D. stramonium are the fruits. After successful pollination, the flower transforms into a large (between 4 and 6 centimeters), egg-shaped fruit with a spiky surface. This spiky fruit is also the reason for the German name “Stechapfel” (literally: “piercing apple”). Each fruit is a capsule with five flaps and contains over 400 black seeds.

D. stramonium - capsule, you can also see the seam
of the flaps

All parts of the plant, but especially seeds and roots, are very toxic due to the high content of Hyoscyamin and Scopolamin. Both belong to a a special group of Alkaloids: the Tropanes. The tropanes are typical for the nightshades and have a strong hallucinogenic effect. However, even small doses can cause respiratory paralysis and death.

the Tropanes of D. stramonium

Despite this, the seeds of D. stramonium are used as drug. This is however not recommend, because this is very dangerous due the high toxicity.

2) Distribution

Originally, D. stramonium was native to Mexico but today it can be found all other world as a neophyte. It was imported to Middle-Europe during the 16th century. The species grows on disturbed areas like ruderal wastelands, dumps but also in garvel pits and even roadsides. It prefers nutrient-rich places to grow and is also tolerant toward salt.