Mittwoch, 26. Dezember 2012

Animal of the Day (December 26th, 2012) - Oryctolagus curiculus


This time, I don't want to show you a plant but an animal. This animal is a "chinchilla rabbit" a sort of the domestic rabbit. (Oryctolagus curiculus). Yeah, this isn't very spectacular, but this little friend appeared a few weeks ago in my parents' garden and is now a regular visitor since then. It's probably somewhere bushed, but feels apparently also in the field very well.


O. curiculus "chinchilla" - habitus


The domestic rabbit comes from the wild rabbit (Oryctolagus curiculus) and was bred probably over 2000 years ago on the Iberian peninsula by farmers. Since these animals reproduce quickly and in large numbers, they were a cheap source of meat. Later, the rabbit also became a popular pet and many new sorts were created.




O. curiculus - beneath a bush


All domestic rabbits descended from the wild rabbit (Oryctolagus curiculus) which is native in Europe. These are small rodents, which are between 35 and 45 centimeters long and have a yellow-brown fur. The most characteristic feature of the rabbit are of course its long ears, which are about 8 centimeters long. they are usually crepuscular, but can also be seen during the day. Their natural habitat are pastures, meadows and other open fields but they can also be found in parks within cities. They live in underground burrows


O. curiculus - on the search for foot


The sort “chinchilla” was bred 1913 in France for the first time (France is the origin of the modern rabbit breeding). In contrast to the wild rabbit, the fur of the Chinchilla is brighter (blue-gray or ash gray). The reason for this is the shutdown of a gene, which is responsible for the yellow-brown color of the wild rabbit. Later, the sort became popular in England and was also imported to other part of the world like Germany.


O. curiculus - the animal is used to humans
and dares to approach them


Like other rabbits, O. curiculus is a herbivore, which eats clover, grass and other small plants. During the harsh seasons (autuumn & winter), the species also eats roots, buds and bark. Rabbits are social animals and live in pairs or small groups. Individual ranking fights within these groups are possible but normal. Life expectancy is about 7 to 11 years. The gestation period of females is about one month with four to eleven pups per litter

Samstag, 22. Dezember 2012

Plants of the Day (December 22nd, 2012) - Tortula ruralis (Hedw.) Gaertn., Meyer, & Scherb. & Grimmia pulvinata Hedw. & Sn.

Today's “Plants of the day” aren't a real plants but a mosses. I'm speaking of Tortula ruralis (Hedw.) Gaertn., Meyer, & Scherb from the Pottiaceae family and Grimmia pulvinata Hedw. & Sn. from the Grimmiaceae. In German, T. muralis is known as “Dach-Drehzahnmoos” and in English as “star moss”. G. pulvinata is known as “Polster-Kissenmoos” in German and in English as “gray-cushioned grimmia”.

Grimmia pulvinata Hedw. & Sn.

G. pulvinata belongs to the Bryophyta, so it's a classic moss and no hornwort or liverwort. The Gametophyte grows in round, blue-green to dark-green (moist) or gray (dry) cushions, which are between 1 or 2 millimeters high.


G. pulvinata - habitus; you can see the silver hairs as
white fluff in the periphery. also on this picture are young
Sporophytes with the bent seta (centre)

The narrow leaflets are between 2 and 3 millimeters long and arranged in an spiral leaf-pattern. They have a distinctive leaf-vein on their back and short, silver-gray hair at the tip, which is almost as long as the leaf-blade. In the dry state, the leaflets lie flat on the stem and unfold when become wet.

G. pulvinata - here, you see older sporophytes (brown); 
the seta has erected.

The Sporophyte has a short seta, which is about 3 to 5 millimeters long, so it protrudes beyond the Gametophyte. However, the young seta is bent and erects only when ripening. During this process, the colour also change from a bright green to a darker brown. The oval capsule have a long beak. Young capsules are bright-green but become brown during ripening.

G. pulvinata - on a bollard in the city

G. pulvinata is a very common moss and can be found in cities on walls, gravestones and roofs. It's also very endurable and has no problem with dryness. Sometimes, it can also be found at the bark of trees but never on the ground.

Tortula ruralis (Hedw.) Gaertn., Meyer, & Scherb.

T. ruralis also belongs to the Bryophyta and is a classic moss (no liverwort or hornwort). The golden-green Gametophyte grows in loose turfs, which have an average height between 2 and 4 centimeters.

T. ruralis - habitus

The narrow leaflets are about 5 millimeters long and are curved what gives the whole foliage a star-shaped look (this is also the reason for the name “Star moss”). Their blunt tips also have long, silver-gray hairs, which are about 1 millimeter long (such hairs at the tip are very common at Bryophyta and protects the leaflets against sun-radiation). In the dry state, the leaflets become twisted.

T. ruralis - here, you can see the sta-shaped foliage

The seta of the sporophyte has a red color. The brown capsules are cylindrical to egg-shaped and sometimes a little bit bent. In contrast to G. pulvinata, the seta of T. ruralis is erected right from the beginning. Another interesting feature of the sporophyte are the left handed teeth of the peristome (the rim at the end of the capsule).

T. ruralis - on a wall

The natural habitat of T. ruralis are calcareous rocks but it has become also very common in cities. So, it can be found on walls, gravestones and sidewalks. Next to G. pulvinata, Tortula muralis Hedw. and Hypnum cupressiforme Hedw., it is one of the most common mosses in our cities.

At first glance, T. rutalis looks very similar to Tortula muralis Hedw. from the same genus and a confusion is possible. The main differences between these two species are the seta, which is much longer at T. muralis, and the star shaped foliage of T. ruralis. Another difference is the serrated silver-hair of T. ruralis but this is only visible with a microscope.

Pleas note: in some literature, T. ruralis is called Syntrichia ruralis (Hedw.) F.Weber & D.Mohr

Dienstag, 18. Dezember 2012

Different models of plant-classification

If you go out and look at the plants around you, you may notice, that they can vary greatly in their form and shape. Some of them are large trees, while other species are small, inconspicuous herbs. In Botany, the kind of growing is a very important, morphological attribute of plants and many models were developed to characterize them. Two of the most popular models are the classification by the growing form of the trunk (“Wuchsform” in German) and the “Raunkiaer Life-Form System”, which was developed by the Danish Botanist C. C. Raunkiaer (1860 -1938).

a Riparian Forests with many perennials and small trees

It's important to say, that a growing form or life form isn't specific to a plant family or genus. A species from a genus can grow as a tree, while another from the same genus can grow as shrub.

1) The characterization of plants by the growing form

As I mentioned before plants can grow in very different shapes. Some of them are small and filigree, while others are large and robust. The morphology is also the starting point of this system. Here, the form of the stem, the maximum height and the degree of lignification are crucial for the category, in which a plant is classified. The classic system distinguish between the following categories.

  • Tree: This is the first growing form, which includes the largest plants on earth. In Botany, a tree is defined as a plant whose main stem axis grows straight and upright. It must also be lignified. The average height is between 1,50 to 40 metres. Within this category, there are also some sub-category; based by the different morphology of the stem.
  • Tropical trees: These are the large trees of the tropical rainforests. They have long stems and sweeping canopy.
  • Broad leafed trees: This common trees are characterized by their wide leaves. Many trees like acer, birch, beech and oak belong to this category. This trees can be seasonal-green or evergreen.

    Acer pseudoplatanus - a seasonal-green tree
  • Conifers: conifers have slim, needle-like leaves (often simply referred as needles). Typical conifers are e. g. pine, fir, yew or cypress. In the most cases, conifers are evergreen but there are also some seasonal-green trees (like larch).

    Cryptomeria japonica - a large conifer
  • Mangrove: Mangroves are trees, which grows in the tropical tidal range. They often have special roots, which serve as stilts. In addition, the cavities within their stems are often filled with air (Aerenchym).
  • Bottle Tree: This trees have a very thick and broad stem, whose tissue serves as a kind of cistern. This trees can be found in the dry regions of Africa like the Savanna. An example for this category is the Baobab.
  • Tuft tree: Tuft trees are a very special form of a tree. They can be found in the mountainous regions of the tropics. Here, the climate is very extreme and we have dry, hot days and cold nights with snowfall. Basically,. a tuft tree is a rosette with a woody stem. The leaves of the canopy are arranged in a rosette, which protects the bud from cold

  • Shrub: The term “Shrub” refers to a plant with multiple, woody stems. Unlike a tree, a shrub hasn't a straight trunk, but several strains of the same order, branching from the same base. However, the boundary between these two definitions is fluent and partly dependent on environmental influences. For example, a beech can grow as a shrub with multiple stems, if it grows in an unfavorable environment (like mountains). 
     
    As for the trees, there are also different subtypes of the shrub. The most important ones are
  • Evergreen shrubs As the name suggest, these shrubs are evergreen and never lost all of its leaves at the same time. Common species from this type are Prunus lauraceus, Skimmia japonica or Rhododendron catawbiense.

    Skimmia japonica - a evergreen shrub
  • Seasonal-green Shrubs: These shrubs lost most of their leaves during a season or a dry period. An example for such plants are the shrub-like species from the large genus Hibiscus, which are very popular as ornamental plants in gardens.
  • Marquis: This are sub-tropical shrubs, which are very common in the Mediterranean regions. They have leathery leaves with a thick cuticula. This is an adaption to drought; caused by the hot summers in this region.

    H. canariense is an example for a marquis
     
  • Stem succulent: This type includes all of the large cacti, which you may known from classic western movies. They are as large as a small tree, but have multiple stems with a thick skin, which protects them dehydration.
Other plants, which are wooden but not trees are grass tree like bamboo and liana. However, these aren't real shrubs but an own, unique type of growing form, which should not be considered any further now.
  • Perennial plants: perennial plants are evergreen, non-wooden plants with a maximum height of 1,60 meters. Although not wooden, their stems are very sturdy and often thick. In the most cases, the stems die after a growing season but return the next year, what is also the major difference between annual or grasses (s. below). Perennial plants haven't to be large. For example, Taraxacum officinale L. (Dandelion) is also a perennial plant. There are also some subtypes within the perennial plants. The most important one are
  • evergreen perennial plants: green over the whole year. Typical species are Phlox panniculata L., Canna indica Ker-Grawl. or the Banana (Musa spec.)
  • Seasonal-green perennial plants: These plants are green only during a certain time of the year. Many common perennial plants belong to this category, e. g. Fallopia japonica (Houtt.) Ronse Decr., or Heracleum mategazzianum Somm. & Lev.

     Fallopia japonica- a seasonal-green perennial plant
  • Succulent perennial plants: Many succulent plants (small cacti) are perennial plants, which have adapted to extreme dryness. Examples are species from the Genus Agave or Bromelia.
     
  • Creeping perennial plants: These perennials creep other the floor. Typical plants are the species from the Genera Saxifraga, Geranium or the Common Ivy Hedera helix L. Creeping plants are very popular in gardens, because they are often evergreen and can be use as turf. 

 Potentilla reptans - a small, creeping plant
  • Grasses, annual and biannual plants: These plants have also no wooden stem. Unlike the perennial plants, they wilt after one (Grasses, annual plants) or two (biannual plants) growing seasons. In the most cases, such plants creates a lot of seeds to ensure their reproduction. These seeds are very resistant and can endure in the soil for other years. This is very common in desert plants, which must withstand for years sometimes.

    Verbascum speciosum - a biannual plant
It's important to say, that these growing types and sub-categories aren't the only one within the vegetable kingdom but only the (in my opinion) most important ones.

2) The characterization of plants by their Life-Form

The model of life-forms was developed by the Danish Botanist Cristen Christian Raunkiaer in 1905 and is one of the most common and popular models to describe the different growing types of plants. One reason for this is, that the model is very simple (much more simple than the system of growing forms).

a slope with many Therophytes, Chamaephytes and Hemikryptophytes

Raunkiaer took as a reference the location of the growing buds on a plant. The growing buds are important for the re-sprouting of a plant after an unfavorable period (like Winter or drying time).Over time, plants have therefore developed various ways to protect their buds, what resulted in a different morphology. These ways are also called life-forms. The classic life-forms after Raunkiaer are

  • Phanerophyte: Phanerophytes are plants, whose growing buds are located high over the ground level at the end of their shoot axis. Here, the buds are exposed to the elements, so they are often covered by sheds or other structures. The most trees and shrubs are Phanerophytes. Tropical trees are an exception because their buds aren't exposed to the elements, so they're also not protected (because it's simply unnecessary). This life-form is also divided in Macro-Phanerophytes (5 meters and higher) and Nano-Phanerophytes. (0,5 to 5 meters).
Planatuns x hispanicus - a Phanerophyte
  • Chamaephytes: Chamaephytes are small shrubs or perennials, whose buds are located a few meters about the soil. They are very common in regions with a harsh, cold winter (like the Tundra), because the snowfall acts as a insulating snow cover, which protects the buds. 

     Vaccinium vitaes-ideaea is a Chamaephyt
  • Hemikryptophytes: The growing buds of the Hemikryptophytes are located on the ground and are often protected by the leaves of a rosette. Many small, evergreen perennials are Hemikryptophytes. The low position of the buds has two advantages. Like the Chamaephytes, the Hemikryptophytes benefits from the insulating effect of the snow cover. In addition, the buds are better protected from wind. For this reason, Hemikryptophytes are very common in the arctic and sub-arctic regions, where the cold wind is a permanent threat for plants
Taraxacum officinale - a Hemikryptophyte
  • Geopyhtes: These plants survive the unfavorable period underground. The majority dies, while the growing bud survives in the soil as a bulb, a tuber or a rhizome. Geophytes are very common in Europe and belong to the first flowering plants of the year, because they sprout in late winter or spring in order to avoid the competition with the large Phanerophytes.
Allium schoenoprasum is a Geophyte
  • Helophytes: Helopyhtes (swamp plants) are similar to the Geophyte. However, their growing buds don't survive within the soil but in the mud. The Helophytes aren't part of the classic model of Raunkiaer and were added later.
  • Hydrophytes: The Hydrophytes are aquatic plants and the growing buds are located beneath water surface. The effect is the same as with the Geophytes and Helophytes. The Hydrophyte were also added later. Together with the Helophytes and Geophytes, the Hydrophytes are described as Kryptophytes, what means “hidden plants” because the buds are hidden beneath surface.
  • Therophytes: These are annual or biannual plants, which “survive” the unfavorable period as seeds while the mother plant dies completely. Therophytes are very common in the desert regions, where the tough seeds often wait years for rain.

    Impatiens glandulifera - an annual plant and a
     Therophyte

The model of Raunkiaer not only helps in the classification of plants, but also for the characterization of vegetation zones. All major vegetation zones (Tropical subtropical, desert, temperate broad and arctic) have their own characteristic composition of life forms, what is an adaption to the climatic conditions of the different zones. Such a composition is called “Life-Form” spectrum. Here are some examples for different spectra after Raunkiaer.

Tropical
P
CH
H
K
T
61
6
12
5
16

Sub-Tropical
P
CH
H
K
T
12
6
29
11
42

Desert
P
CH
H
K
T
12
21
20
5
42

Temperate broad
P
CH
H
K
T
10
5
50
15
20

Arctic
P
CH
H
K
T
1
22
60
15
2

All figures in percent;
P = Phanerophyte, CH = Chamaephyte, H = Hemicryptophyte, K = Cryptophyte, T = Therophyte.

As you can see, the spectra are a good way to characterize the different vegetation zones, because it's very logical. For example, the Arctic (and Antarctic) regions are well-known for a harsh, cold wind. So, here are not so many Phanerophytes because their buds are exposed to the wind.

a broad temperated forest

The Hemikryptophytes on the other side are well protected against the wind and so, Hemikryptophytes are characteristic for the flora of the arctic regions. If you go online and look for some pics about Spitzbergen, Tasmania or Iceland, you will see, that there are many Hemikryptophytes.

Thus, I arrived at the end of the article. I hope to give you an overview of the growing forms and life forms of plants and these have occurred not by chance. Of course, the article includes not all forms (there are also parasites and epiphytes). For reasons of simplicity, however, the basic shapes are sufficient.

Please note: The picture of Vaccinium vitis-ideae were taken by Christopher Schwerdt. I have his permission to use these pictures in my blog. Please also visit his homepage www.schwerdtfisch.net


Montag, 17. Dezember 2012

Important message

Hi,

as you maybe noticed, there were no new posts in this Blog for nearly two weeks. I'm sorry, but i was very busy and didn't find the time to wrote something. However, this blog isn't dead. In this moment, I'm writing an article about the different life forms and growing forms of the higher land plats, which will go online at Tuesday or Wednesday. So stay on and thanks for you patience. ;-)

mfg
Sebastian

Dienstag, 4. Dezember 2012

Plant of Day (Dezember 4th, 2012) - Hypericum canariense L.

Today's “Plant of the Day” is Hypericum canariense L. from the Hypericaceae family (St. John's Worth). In English, the species is known as “Canary St. John's Worth” and in German as “Kanarisches Johanniskraut”. In Spanish, the species is called “Grenadillo”.



H. canariense - inflorescence & leaves


Unlike the more common Hpericum perforatum L. (St. John's Worth), this species is a medium high shrub, which can reach a maximum height of nearly 3 meters (9.8 feet). A total height of 7 meters (22.9 feet) is also possible. It grows multi-stemmed and the smooth bark has a medium brown color. There is also a richly branched rhizome, which is used to anchor the plant in the soil.

H. canariense - stems

The narrow leaves are lanceolate and between 2 and 7 centimeters long. They have a prominent, white leaf-vein on their dorsal site and are arranged in an opposite leaf-pattern. Another prominent feature is the thick, waxy cuticula. However, H. canariense isn't evergreen. The foliage is green during winter but change its color later to an orange during summer. At the end of the summer, the leaves are dropped.

H. canariense - leaves; on this picture, you can see
the white leaf-vein and the opposie leaf-pattern

The inflorescence are cymes, while the flowers are similar to the flowers of H. perforatum. There are five sepals and five petals. The small sepals are ovate and have a cilliated margin. The petals have a orange to yellow color. Like the most species from the Genus Hypericum species has numerous of anthers. There are also three stigmas. The ripe fruits are black, leathery capsules, which open in late summer (between June and August) after ripening.

H. canariense - inflorescence; the three styli per are encircled 
also on this picture, you can see the anthers (a), petals (p) and sepals (s)

As the name suggest, H. canariense is native to the Canary Island, which are located before the shores of West Africa. More precisely, the species grows only on the five western islands (El Hierro, La Palma, La Gomera, Tenerife and Gran Canaria) of this group of islands. It grows on the slopes of former volcanoes between 150 and 2000 metres and is part of the laurel forests. These are forests of xeromorphical shrubs and small trees, which have adapted to the high temperatures during spring and summer (the waxy leaves are an example for such an adaption).

However, H. canariense can also be found in North America and Western Australia as Neophyte. For example, the species is very common in the counties of Los Angeles in California (USA) and Victoria (Australia). Probably, this individuals are former ornamental plants, which started to grow wilde, because the environmental conditions are the same like on the Canary Islands (hot summers, laurel forests and rocky slopes)