Sonntag, 22. Juni 2014

Portrait: Ornithogalum umbellatum L.

In this article, we want to take a closer look on Ornithogalum umbellatum L. from the Asparagaceae family. In German, this species is known as “Dolden-Milchstern”, while common English names are “Stare-of-Bethlehem”, “grass lilly” or “11'o clock flower”. Please note: in older literature, the plant still belongs to the Lilliace

1) Description

As with many members of the Asparagaceae family, O. umbellatum is a perennial plant and can reach average heights between 10 and 30 centimeters. Each plant has between six or nine leaves, which arise from the base (so the stalk is completely leafless). This leaves are very long and tower over the inflorescences clearly. They are also very fleshy and between five and six millimeters width. Another, distinctive feature of the leaves is the milky-white gutter, which goes until the leaf-tip. 

O. umbellatum - habitus

As I said it before, O. umbellatum is a perennial plant, so it has to outlast harsh times (like winter). For this purpose, the plant uses an underground bulb, which consists of a main bulb and some smaller side-bulbs.

 O. umbellatum - the pictures were made on a cloudy day;
so the flower is nearly closed

The inflorescences are umbel-like racemes, which consist of ten to fifteen flowers. As with all monocotyledons, the flowers of O. umbellatum has two circles of identical tepals with three tepals per circle. Each tepal has a snow-white color and a distinctive green stripe on their dorsal site. Flowering time is between April and May. The ripe fruit is an oval capsule with many seed within. 

 O. umbellatum - another look at the flower

Some of the most interesting features of this species is its phototropism. It reacts on sunlight and open the flowers only at sunshine. During bad weather of at night, the flower is closed.

2) Distribution

O. umbellatum is native to the Mediterranean, but can also been found in Middle Europe, northern Africa and Western Asia. It grows also in some areas in North America, where it was imported as an ornamental plant.

 O. umbellatum - typical habitat

The species prefers a nutrient-rich soil on clay and grows on fresh meadows, vineyards, parks and even roadsides.

Montag, 2. Juni 2014

Portrait: Orobanche caryophyllacea Sm. (and Orobanche caryophyllacea f. citrina A. Dietr.)

This time, we want to take a closer look on a species from the Ororbranchaceae family („broomrape“ in English and „Sommerwurzgewächse“ in German). This species is Orobanche caryophyllacea Sm. (German: „Nelken-Sommerwurz“). We will also take a short look on Orobanche caryophyllacea f. citrina A. Dietr.; a subspecies of O. caryophyllacea

1) Description

The Orobanchaeceae are a family, which is strongly related to the Lamiaceae and Scrophulariaceae families. Actually, the Orobanchaeae were part of the Scrophulariaceae but today, their 12 Genera form an own family. Their leaves have no chlorophyll and as a result, they are not able to make photosynthesis. So, nearly all of them are parasites, which leech on other plants (mostly other Dicotyledones).

1.1) Orobanche caryophyllacea Sm.

O. charyophyllacea (Genus: Orobanche) is probably one of the best-known species from the Orobanchaceae. In Germany, the species is known as “Nelken-Sommerwurz” but other common names are “Gewöhnliche Sommerwurz”. 

O. charyophyllacea- habitus

It's a annual or perennial plant, which can reach a maximum height between 20 and 50 centimeters. Due the lack of any chlorophyll, the stalk has a purple to brownish-purple color and isn't green. The leaves are small an scale like. This morphology is a result of evolution: the plant doesn't need large leaves, because it makes no photosynthesis. So, they were reduced during the time.

O. charyophyllacea- flower (note the glands and the
purple stylus)

The root is a thick bulb. From here, small projections (Hausteria) penetrate into the root of the host plants. This happens right after the germination of the seeds.

The cygomorphic flowers are arranged in a single, loose pannicle. All petals are grown together at their base and form a tubular structure. At the apex of the flower, the two upper petals form a large lip, while the other three petals form three, small tips. Such flowers are mostly pollinated by larger insects or even small bird, which have to crawl into the flower for nectar and as a result, they take many pollen with them.

O. charyophyllacea- habitus


The calyx is small and consists of five, free sepals. The flowers have the same color like the rest of the plant. Another interesting detail: the flowers smells like cloves, what is also the reason for the suffix “caryophyllacea”.

In addition, the whole flowers are covered with glands.

 O. caryophyllacea f. citrina  -
habitus

Flowering time is between Mai and July, which makes O. caryophllacea to one of the earliest blooming members of the Orobanchaceae in Europe. The seeds are very small and only about half a centimeter in diameter. 

O. caryophyllacea f. citrina - flowers
(in contrast to the main species, the stylus is yellow and
not purple)
 
The specific host of O. caryophyllacea are plants from the Genus Galium from the Rubiaceae. By its Hausteria, the parasite robs water from the host and reduces its quality of live. So, O. caryophyllacea is also known as “galium-strangler”.

1.2) Orobanche caryophyllacea f. citrina A. Dietr.

This is a more rare subspecies of O. caryophyllacea, but it's anatomically the same plant. However, the most distinctive difference between the main species and O. caryophyllacea f. citrina A. Dietr. is the color. As you can see on my picture, the flowers and the stalk of the subspecies has a golden yellow color. So, it looks more spectacular than O. caryophyllacea.

O. caryophyllacea f. citrina -
inflorescences 

The exact reason for this contrasting color isn't clear. In my opinion, it's a mutation of the Genes, which are responsible for the pigmentation. This is the most obvious solution for me.

2) Distribution & Ecology

Members of the Orobanchaceae can be found all over the world. However, the most genera are native to the temperate regions of the old world (Europe and Asia). Due the high specification towards their hosts, the distribution also depends a little bit on the distribution of the host.

such a meadow is a typical habitat for
O. caryophyllacea

O. caryophyllacea (and Orobanche caryophyllacea f. citrina A. Dietr.) are native to Europe and Western Asia. It prefers warm places on lime and a nutrient-rich soil. The species can be found on warm, dry meadows (this is a special kind of biotop, which is called “Trockenrasen” in German) and sunny shrubberies along paths.

Freitag, 21. März 2014

Species of the Day (March 21st; 2014) - Stereocaulon vesuvianum (Sm.) Ach.

Today's “Plant of the Day” isn't a real plant but a lichen. This lichen is Stereocaulon vesuvianum (Sm.) Ach. from the Stereocaulaceae Family. The species has no common name but the literally translation of the species' name means “Mount Vesuvius Stereocaulon” in English (“Vesuv-Stereocaulon” or “Vesuvflechte” in German).

1) Description

S. vesuvianum is a flat lichen. The greyish-green to green Thallus grows flat on the substrate at the beginning but erects later with many branches, which are about 4 centimeters high. These branches are irregularly shaped and grows in any direction. As a result, the habitus of S. vesuvianum reminds to the smoke clouds from an erupting volcano like Mount Vesuvius. This is also the reason for the name “vesuvianum”. 

 S. vesuvianum - on a stone

These “branches” are more long protrusions of the cells of the Thallus and not a real ramification. In Lichenology, such a structure is called a Pseudopodium. In the case of S. vesuvianum these branches have a greyish color with a small touch of orange (what reinforce the impression of a volcano).

S. vesuvianum - habitus

Soredia (small, clustered fragments of the Thallus) are located at the end of the Pseudopodia. They serve for asexual reproduction by breaking off from the lichen in order to form a new Thallus. Many lichens prefer this way of reproduction over the sexual reproduction by spores. Especially under tough conditions, an asexual reproduction is much easier than a sexual.


S. vesuvianum - you can see the pseudopodia

Apothecia are rare. However, if they are present, they are also located at the apices of the pseudopodia, where they create spores for the sexual reproduction. The measurements of these spores are about 40 X 3,5 µm, so they are much longer than hight. The spores are also septated in 3 to 5 sub-sections.

2) Distribution and Ecology

Despite the name, S. vesuvianum isn't endemic to the regions around Mount Vesuvianus. The species is a cosmopolitan and very common in both hemispheres. So, it can be found in Europe, but also in Asia or Australia. S. vesuvianum prefers siliceous and acid substrate and grows on rocks, walls or gravel.

Freitag, 14. März 2014

Plant of the Day (March 14th, 2013) - Bryum barnesii J. B. Wood.

In my last post, I presented you Bryum argenteum; a very common moss. This time, I want to show you another moss, which is also very common in cities and everywhere else. This species is Bryum barnesii J. B. Wood., which is also a member of the Bryaceae, of course. In German, the species is known as “Zweifarbiges Birnmoos” and in English as “Bicolored Bryum”.

Please Note: the exact status of B. barnessii as species is still unclear. In many books and publications, the species is threatened as a variety of Bryum bicolor and part of a larger Bryum bicolor complex. As a result, the information in this article also apply for B. bicolor.

1) Description

B. barnesii is a small moss, which can reach heights between 1 and 1.5 centimeters. The species grows in loos turfs or cushions. The small leaflets are only about 2 millimeter long. A clearly protruding leaf-rip originates from the base over the entire leaflet to the tip. Unlike B. argentum, there are no different kind of leaflets and also no chlorophyll-free, glassy tip.

B. barnesii - between two concrete slabs

The Sporophyte of B. barnesii is inconspicuous. The brown seta is only about 15 millimeters long. The egg-shaped capsules with the spores are pendulous and pass abruptly into the seta. Normally, the sprophyte is created during autumn

B. barnesii - habitus

However, the distinctive character of B. barnesii are the Gemmae. In Bryology, a gemma is a instrument of asexual reproduction. Normally, a Gemma consists of a single cell or is a tissue, which is splitted off the plant and grows up as a new individual plant. This kind of reproduction is very useful, if the plant has no sexual partner but has to reproduce in order to survive harsh times.

 B. barnesii - closer look on the shoots

In the case of B. barnesii, the Gemmae are small bulbs, which are located in the axil of the leaflets. A single shoot of B. barnessi has 5 of the Gemmae, which are all located at the top of the shoot. However, 11 Gemmeae are also possible. In contrast to this, B. bicolor has often not a single Gemmae or only one on some shoots. For some scientists, this high number of Gemmea is enough to declare B. barnessi as a new species. Other researchers think that the high number of Gemmae is only a variation of B. bicolor but not an own species.

2) Distribution

B. barnesii is a cosmopolitan and very common in the most parts of the world. It prefers fresh but also bright places and a chalky surface to grow. The species is weak in competition with other plants. As a result, it avoids competition and grows on ruderal wastelands, concrete slabs or even wall cracks.

 as with many other mosses an urban area
is the typical habitus of B. barnesii

In many cases, the species grows together with B. bicolor of B. argenteum


Freitag, 28. Februar 2014

Plant of the Day (February 28th, 2014) - Bryum argenteum Hedw.

Today's “Plant of the Day” is Bryum argenteum Hedw. from the Bryaceae family. In English, the species is known as “Silver moss”. The German name is “Silbermoos” but “Silber-Birnmoos” is also very common.

1) Description

B. argenteum grows in dense and compact turfs. The cylindrical shoots of the Gametophyte are mostly around 1 centimeter long, so it isn't a very tall moss. However, these shoots are densely covered with small “leaves” (we call them leaves but in fact, mosses have no real leaves like the higher plants). These leaves are tiny and only between 0.5 and 1.25 millimeters long.

B. argenteum -between to concrete plates

However, the leaves are a distinctive character of identification for this species. There are two kinds of them: the basal leaves of the shoot and the leaves, which are located at the top of each shoot. The basal leaves are more spade-shaped, while the other leaves are more round but with a significantly narrowed tip. This tip has no chlorophyll and as a result a silver to white color, when dry. 

B. argenteum - habitus; you can see the silver tips
 
In both cases, the leaves are concave curved and have a leaf rib on their dorsal site. However, these rib goes not to the tip but ends in the middle of the leave blade. Both kind of leaves lie directly on the shoot like scales. However, protruding leaves are also possible; especially in the dry state.

 B. argenteum - the distinctive, silver shimmer

By the white color of the leaf tip, which I've described above, the stocks of B. argenteum shimmer silver, when dry. This is also the reason for the name of the species (“Argentum” is Latin and means “silver”).

The Sporphyte of B. argenteum is kept simple with a Seta and a capsule, which contains the spores. The Seta is about 1 centimeter long. The capsules at the end are pendulous or nearly horizontally. They are produced between autumn and spring.

2) Distribution

B. argenteum is a cosmopolitan and widely distributed. It benefits largely by the anthropogenic influence, because it prefers nutrient rich places to grow. Thereby, the species can be found nearly everywhere like ruderal wastelands, railway line or even in the cracks between concrete slabs. 

B. argenteum - is widey distributed in urban areas
 
As with the most species, B. argenteum can grow even under the most adverse circumstances and has also the ability to endure longer periods of dryness.

Mittwoch, 19. Februar 2014

Cryptogams of the Ruhr-University Bochum 2014

As in the years 2012 and 2013, I participated in a Field Trip to the Ruhr-University, which looks for Moses, Lichens and Fungi, which grow in the urban surrounding of the campus. So, it's also time for a new report about this field trip. Unfortunately, I didn't made a report in 2013, because there was to many snow and so I hadn't enough lichens or mosses for an interesting report. So, the temperate winter, which we have in Germany this year, may not be good enough for winter sports but it's ideal for some kind of hobby Lichenology. The Field Trip was organized by the “Botanischer Verein Bochum e. V.”, of which I'm a member.

1) The areal

The field trip is part of a series of field trips, which examine the population and diversity of lichens and mosses at the Campus of the Ruhr-University in Bochum, Northrhine-Wesphalia. It started three years ago in 2011 and each year, another part of the Campus was examined. This year, the field trip takes a closer look at a small area in the south west of the University. It starts at the “Kulturcafe”, a meeting point for students, and leads along the facades and over the rooftops of the buildings, which host the faculty of medicine. 

Campus of the Ruhr-University; the concrete plates
are ideal for liches

As with many urban areas, the Campus of the Ruhr-University is a good place to find many different lichens and mosses. The buildings are made of concrete, whose rough ground is ideal for these organisms to adhere. In addition, the different composition of concrete, which is often made of many various kinds of rocks, provides a potent high diversity of species in a small areal. For example, on a piece of a wall, which is made of very calcareous concrete, you can find lichens, which prefers lime. On the other side, you may find more acid preferring lichens on a concrete wall, which is made of gravel.

Another impression of the areal

Another advantage of such places is the missing of dense vegetation. As a result, Mosses and Lichens are easier to detect and also not in competition with higher plants for light, nutrients and water.

2) About Lichens & Mosses

In past articles, I've already written about the basic attributes and the biology of Mosses & Lichens, so a repeat at this place wouldn't make sense. So, if you want to know more about these very interesting organisms in detail, just look at my other Articles about the the last field trip and the basics about lichens.

3) List of Species


4) Pictures

Lichens

C. citrina

 C. concolor (yellow)

Cladonia chlorophaea

Cladonia subulata

  Cladonia furcata

 Evernia prunastri - here on a wall and not on a tree

 Flavoparmelia caperata

 Hypogymnia tubulosa

Hypogymnia physodes

Lecanora dispersa

 Lecanora muralis

Stereocaulon vesuvianum

Physcia caesia
 

Mosses

 Grimmia pulvinata

 Bryum caespiticium

Polytrichium juniperinum

Bryum argentum

 Bryum barnesii

Ceratodon purpureus

 Funaria hygrometrica

Tortula ruralis

Other species

 Dacrymyces stillatus (orange spots on wood)
 
 Paranectria oropensis (orange spots on the lichen)

Geastrum triplex

Montag, 3. Februar 2014

Species of the Day (February 3rd, 2014) - Geastrum triplex Jungh.

This time, I have a special kind of fungus for you. This species is Geastrum triplex Jungh. from the Geastraceae Family. In German, this species is known as “Halskrausen-Erdstern”. The common English name of this fungus is “Collared Earthstar”, what is also the literally translation of the German name.

1) Description

G. triplex is a larger fungus, whose mushrooms (the fruit bodies, which carry the spores) reach 6 to 10 centimeters in diameter. The above-ground mushrooms grow in stocks of two or three fruit bodies per stock.

G. triplex - habitus

The most distinctive feature of G. triplex (and the most other species from the Genus Geastrum) is the habitus of the mushrooms, which remind of tuber, which grow in a star-shaped rosette. These habitus is a result of the ripening. Young mushrooms are tuber-shaped, when they sprout from the ground. Basically, a mushroom of G. triplex consists of two different layers: the Exoperidium and the Endoperidium with the spores. During the ripening, the Exoperidium breaks up and forms a saucer-like pedestal for the smaller Endoperidium. Later, the Exoperidium tears up into star-shaped rays, which surround the Exoperidium. A stem is missing.

Ripening of a G. triplex mushroom: 1) intial phase; 2) medium phase
3) final phase (with spore erruption)
(exp =  Exoperidium; end = Endoperidium (in 2) with cracks; in 3) star shaped;
s = spores; h = hyphae; o = ostiole; c = collar)


This process is typically for all fungi from the Genus Geastrum. In addition, the Endoperidium of G. triplex also flakes off at the base and form a kind of collar around the Endoperidium. This is also the reason for the name “Collard Earthstar”. However, this collar may be missing or be only very inconspicuous. This leads to confusion with other species of the same Genus. In the most cases, G. triplex is confused with the similar Geastrum sessile (Sow.) Pouz., which is much smaller and never has a kind of collar.


G. triplex - younger mushroom in phase 2

As I said it before, the spores are inside the Endoperidium and leave it after ripening by the large pore at the the top of the mushroom (in Mycology: Ostiole). This eject often happens by an abrupt eruption. The spores are spherical and between 3 and 4 micrometers in diameter. They are also covered with some warts.

G. triplex - two mushrooms in phase three; the
ostiole and the collar are visible

G. triplex isn't poisonous. However, the whole fungus is completely uneatable, because the tissue is tough and has no taste.

2) Distribution

G. triplex is a cosmopolitan and can be found all over the world (e. g. in Europe, North America South Africa etc.). It's a saprobe and thrives on dead, organic matter, from which it gets its nutrients by decomposing. Normally, this species can be found in deciduous forests on lime in the undergrowth or along rotten trunks and tree stumps. However, it can also be found sometimes in parks or bushes with a high entry of organic matter. I found this fungi on the campus of the Ruhr-University in Bochum, Western Germany.