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
bracts

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.