Montag, 27. Februar 2012

Evergreen Plants, trees and scrubs at the "Südfriedhof" in Herne

Recently, I participated in a new Field Trip; this time to the “Südfriedhof” (literally “southern cemetery”) of Herne, a small town in Western Germany. This field trip was planned and carried out by the “Botanischer Verein Bochum” (Botanical Society of Bochum). For further information, check out their homepage (use google, because I don't know if deeplinking is allowed). The main focus of the field trip was upon the evergreen plants. So, in this Post, I want to present you some evergreen species, which we've found on the area of the cemetery. But first, it's time for a little bit history.

1. The Southern Cemetery of Herne

This cemetery is located in the South of Herne in Western Germany. It was founded in the year of 1905 by the city council, which bought an uncultivated area at the “Wiescherstraße”; a road which connects the small town with the town of Bochum in the south. Before the founding, the dead were buried on smaller cemeteries and, until 1850, in the neighborhood of the town church.

a fountain at the cemetery

Over the centuries, the area was extended multiple times. The first expansion was in the year of 1908 0,5 ha. Other expansions happened in the years of 1920/21 (3,5 and 12 ha), 1930 – 1932 (3,5 ha) or 1990 (20 ha). So today, the whole cemetery hat a total area of 34 ha, which makes it to the biggest cemetery of Herne.

view at the cemetery

The “Südfriedhof” is the final resting places of many people, who have made outstanding contributions to the Town of Herne or play a major role in its history. The most of them were businessmen, who founded major factories or productions plants in Herne, that brought prosperity to the town. Of course, many of this companies have something to do with mining, because Herne is part of the “Ruhrgebiet”, one of the former major areas of mining in Germany. But also many local politicians are buried here.

the left part of the chapel

Beside this, there are also some honorary graves on the cemetery. One of them is dedicated for the dead soldiers of both World Wars, while another is for the civilians, which were killed during allied bombing raids. There is also honorary graves for foreign victims of World War II. The most of them were Soviets and Poles. They were Prisoners of War, who were abducted by the Germans in order to work as forced labors in the factories and mines.

Graves of the forced labors

Other interesting places are the two memorials for the victims of two mining disasters and the memorial of demonstrators, who were killed at at demonstrations against a coup attempt (Kapp-Putsch) in the year of 1920.

Another very touching place is a burial ground “Pusteblume” (dandelion) for preemies and miscarriages.

In the center of the “Südfriedhof” stands the chapel, which was completed in 1909 and is built in the style of Neoclassicism.

2. Evergreen Plants on the Cemetery

Evergreen species are very popular for cemeteries, because in many mythologies evergreen symbolized also eternal life. However, this species are not really “evergreen”, because they also loose their leaves but not in such a big number as abscissional plants and new leaves replace the old ones also over the whole year. A true evergreen plant is Weltwitischia mirabilis Hook. F.; an indigenous plant of Namibia, which produce only two leaves in its long life.

Many of these evergreens on cemeteries have also hanging leaves or branches, because this is a symbol for mourning. Since the cemetery is also a park, the planting should not be too high.

Because of this, cemeteries plants are often small, scrub-like conifers or special breeding of the wild forms.

3. List of Species

Name Familie
Rhododendron catawbiense Michx. Ericaceae
Skimmia reevesiana Fortune Rutaceae
Skimmia japonica Thunb. Rutaceae
Taxus baccata L. Taxaceae
Chamaecyparis lawsoniana (A. Murr.) Parl Cupressaceae
Chamaecyparis obtusa Endl. Cupressaceae
Chamaecyparis pisifera Endl. Cupressaceae
Juniperus chinensis L. Cupressaceae
Abies pocera Rehd. Pinaceae
Thuja occidentalis L. Cupressaceae
Platycladus orientalis (L.) Franco Cupressaceae
Microbiota decussata Kom. Cupressaceae
Tsuga canadensis (L.) Carriere Pinaceae
Picea glauca var. Albertiana (Moench.) Voss. Pinaceae
Aucubua japonica Thunb. Garryaceae
Juniperus squamata D. Don Cupressaceae
Picea pungens Engelm. Pinaceae
Abies koreana E. H. Wilson Pinaceae
Pinus mugo Turra Pinaceae
Pachysandra terminalis Sieb. Et Zucc. Buxaceae
Picea omorika (Pankc.) Purk. Pinaceae
Ilex crenata Thunb. Aquifoliacae
Osmanthus heterophyllus (G. Don) P. S. Green Oleaceae
Pieris japonica (Thunb.) D. Don Ericaceae
Picea parviflora Sieb. & Zucc. Pinaceae
Cedrus atlantica endl- Manetti Pinaceae
Tsuga heterophylla (Raf.) Sarg. Pinaceae
Cupressus macrocarpa Hartw. Cupressaceae
Xanthocyparis nootkatensis D. Don, Farjo et Harder Cupressaceae
Picea wallichiana Jacks. Pinaceae
Metasequoia glyptostroboides Hu & Cheng Cupressaceae
Pinus nigra J. F. Arnold Pinaceae

3. Pictures

Cupressaceae

 Chamaecyparis obtusa - variety "nana gracilis"

Chamaecyparis lawsoninana - white sort

 Chamaecyparis lawsoninana - green sort

 Cupressus macrocarpa - sort "Goldcrest"

Chamaecyparis pisifera - Sub-Clade "Filifera"

 Chamaecyparis pisifera - Sub-Clade "Squarrosa";  "Boulevard" Variety

Juniperus chinensis

Juniperus squamata - "Blue Star" Sort

Platycladus orientalis

Thuja occidentalis 

 Xanthocyparis nootkadensis

Pinaceae

 Abies koreana
 Abies procera

 Cedrus atlantica - "Glauca" Variety

Pinus omorica - a glacial relict

 Picea pungens

 Pinus mugo 

Pinus parviflora

 Pinus wallichiana

Tsuga canadensis

Taxaceae

Taxus baccata - male plant with male cones

Non conifers
 Aucuba japonica

 Ilex crenata

Osmanthus heterophyllus - "Goshiki" Sort

 Pachysandra terminalis

 Pieris japonica
 Rhododendron catawbiense

 Skimmia japonica

Skimmia reevesiana 

Freitag, 24. Februar 2012

Plant of the Day (February 24th, 2012) - Galanthus nivalis L.

Spring is dawning in Middle Europe and the first flowers of the year are appearing these days. One of these “Early flowers” is Galanthus nivalis L., from the Amaryllidaceae family; which is also the family of the Narcissus (Narcissus pseudonarcissus L.) In Germany, this plant is known as “Kleines Schneeglöckchen”, while in the English language, this species is called “Common snowdrop”

G. nivalis - habitus

It's a small herb, which can reach only a height between 8 and 20 centimetres (3.2 to 7.9 feet). The narrow and lineal leaves are blue-green. As a monocotyledon, the leaf-veins are parallel to each other. They have also a small keel in the middle. The stalk grows upright.

Parts of the root are transformed into a thick bulb

The inflorescence is a single, nodding flower at the top of the stalk. These flowers is typical for the monocotyledons. They are not divided into petals and sepals, but tepals. This structure is called Perigone.

G. nivalis - flower

Each Perigone consists of an inner and an outer circle of tepals with three tepals per circle. This is also another typical character of the monocotyledons. The outer tepals are pure white, while the inner ones are also white but with a green spot at the top.

The Gynoeceum is inferior and the ripe fruit a small seed, which is spread by ants. Flowering time is from December to April, but the main time is between January and February.

G. nivalis - habitus

G. nivalis is native to Middle and Southern Europe and can be found as wild form in the mountainous regions of South Germany, Switzerland, Austria, France and the Balkans, where it grows in forests on lime. However over the years, the common snowdrop has become a very popular garden and ornamental plant and can be found today as harbinger of the spring in many other regions of the world (e. g. Northern Europe, North America).

These plants are normally not the wild form, but cultured forms for gardeners.

All parts of G. nivalis contain an alkaloid named Galanthin. It's part of a medicine, which is used to treat the symptoms of Morbus Alzheimer. On the other side, this Galanthin is also poisonous and can caused gastro-intestinal upsets.

Mittwoch, 22. Februar 2012

No Posting?

Perhaps, some of you have noticed, that I haven't posted an Article the last two times, but unfortunately, I have not the time. But don't be afraid, I'm still allive and will post a new article this Friday. :)

Montag, 13. Februar 2012

Fruits of the angiosperms

In this Article, I want to write something about the fruits of the Angiosperms. My goal is to give you some information about the different types of fruits, their anatomy and their creation. This Topic will be divided into two sub-articles. The first one should clarify the basic definition of the term “fruit”, their anatomy and the different fruit-types.

1 Definition of a fruit & Basic anatomy

Fruits exists in many forms and variations. Some are big and beautiful, other ones are small and inconspicuous. They are smooth or hard. However, there is a clear definition of the term “Fruit” in botany; regardless of their shape and seize.

A fruit is a flower at the time of the maturation of its seed”

That means, that a fruit is the metamorphosis o the floral organs of a flower after the pollination. In the most cases, these organs are the female ones: the Carpels. After successful pollination, the carpels will become a new structure, which is called Pericarp. The Pericarp is subdivided in three layer: the Endocarp (central part around the seed), the Mesocarp (the largest part) and last but not least the Exocarp (the outer layer). In some cases, especially the citrus, the Mesokarp is called Albedo, because it has a white color 

 
A good example is the peach: Take one and cut in right through the middle. You will see the hard core (endocarp), the yellow fleshy layer (mesocarp) and a hairy skin (Exokarp). Unfortunately, I've no picture, because you cannot buy peaches in Germany during winter.

The Morphology of these three layers is essential for the type of fruit. There are the following basic types, based on the composition of their layers.

2. Types of fruit

Now, it's time to take a closer view on some types of fruits. First, we start with the simple ones. In this case, the flower had only one carpel.

Table 1: Basic Types of Simple fruits
Type
Endocarp
Mesocarp
Exocarp
Opening mechanism
Example
Follicle
Leathery, dry
Leathery, dry
Leathery dry
Along the ventral side
Genus: Consolida
(larkspur)
Legume
Leathery
Leathery
Leathery
Along the ventral and dorsal side
All Fabaceae (e. g. peas, beans)
Berry
fleshy
fleshy
fleshy
none
Genus: Actaea (baneberry)
Drupe
hard
fleshy
leathery
none
Genus: Prunus (peaches, cherries)

However, many plants have more than one carpel. In this case, the ripe fruit is a compound fruit and we need to divide the fruits into two subtypes: apocarp and coenocarp. Apocarp fruits are fruits with at least two, free carpels, while the carpels of coenocarp fruits are grown together.

Please note, that only the number of carpels is relevant, if a fruit is a compound fruit or not. A flower can have only on seed but two or more carpels.


Table 2: Coenocarp compound fruits
Type
Endocarp
Mesocarp
Exocarp
Opening mechanism
Example
Berry
Fleshy
Fleshy
Fleshy
none
Solanaceae (tomatoes, potatoes)
Nut
Hard (woody)
Hart (Woody)
Hard (Woody)
none
Hazel. walnut
Caryopsis 1)
Hard (woody)
Hart (Woody)
Hard (Woody)
none
All Poaceae (grasses)
Achene 2)
Hard (woody)
Hart (Woody)
Hard (Woody)
none
Asteraceae
Drupe
hard
fleshy
leathery
none
Sambucus
Capsule
dry
dry
dry
Variable
Many different families

1) The Caryopsis is the nut-fruit of the Poaceae (grasses). It's based on three carpels, but two of them are so heavy reduced, that the Caryposis seems to have only one carpel

2) The Achene is the nut-fruit of the Asteraceae (Dandelion, Daisy, Sunflowers). The Pericarp is connect with the embryo (but not fused), what makes it to a special form of the nut.

Table 3: Apocarp compound fruits
Type
Endocarp
Mesocarp
Exocarp
Opening mechanism
Example
Compound Nut
Hard (woody)
Hart (Woody)
Hard (Woody)
none
Genus Geum
(Aven)
Compound Follicle
Leathery, dry
Leathery, dry
Leathery dry
Along the ventral sides
Genus Paeonia
(Peony)
Compound Drupe
hard
fleshy
leathery
none
Genus: Rubus (Blackberry; Strawberry) 1)

1) It's a common mistake to call these fruits “Berries” but they are compound fruits, which consists of many small Drupes

3. Opening Mechanism

After ripening, the main function of a fruit is to spread the seed. There are many strategies of spreading, but this should not be a topic of this posts. For now, yo need to know, that a fruit can be opened or not and that this opening can happen in many different ways.

  • Indehiscent fruits: This type does not open. The ripe fruits remain as whole on the tree or fall down. Nuts, berries, Drupes and so on are indehiscent fruits

  • Dehiscent fruits: The ripe fruit opens along a seam. Examples are Follicle, Legume or pods. Another, special variant are capsules, which opens in many different ways like through a cap, pores or by a burst (e. g. Impatiens)
Another opening mechanism is the disintegration of the fruit (s. 4)

4. Shizocarp fruits

There are also other types of fruits, which don't fit into this scheme. These fruits form fake wall beside the carpels and disintegrate after ripening along these fake walls. This fruits are called Shizocarp. It's a fusion between the morphology of the fruit and it's opening mechanism.

The most important types are:

  • shizocarp fruits: these are compound fruits with two carpels, which disintegrate along their septa into to sub-fruits (Mericarps). Good Examples are the fruits of the Acer or the Apiaceae family. In the later, the fruits remain linked by a stalk, which is called Carpophor
  • Klausenfrucht: this is the special fruit of the Lamiaceae and Boraginaceae families. Unfortunately, I haven't found a English name. Both families have two fused Carpels and four seeds. They form fake septa within the carpels and at ripening, the fruit disintegrates into four mericarps.
  • Articulated legume: This is a special form of the legume. Fake septa separated the legume into smaller mericarps.
That should it be for today. In the next Article, we will take a closer view on the anatomy of a fruit and the structures within it.

5. Pictures and Examples

 Malus domestica as example for
follicle (please rember, that the pulp doesn't belong
to the fruit)

 Rubus laciniatus as example for compund drupe

 The fruits of Sorbus aucuparia are berries

The legumes of Robinia pseudoacacia

The nut of Quercus robur

The fruits of Aesculus hippocastanum are also nuts
(the spiky hull is an extra structure and not a part of the fruit)

 Acer pseudoplatanus with its winged, shizocarp fruits

Montag, 6. Februar 2012

Plant of the Day (February 6th, 2012) - Ilex aquifolium L.

Today's Plant of the Day is Ilex aquifolium L. from the Aquifoliaceae family. In Germany, this species is known as “Europäische Stechpalme” or “Gemeine Stechpalme” and in the English language as “Holly” or “European Holly”.

I. aquifolium - habitus
It's an evergreen shrub or tree, which depends on ecological factors like climate and soil.
As a shrub, I. aquifolium can reach height between 1 and 6 metres, while as tree heights between 10 and 15 metres.
The shiny leaves are dark-green and leathery. In order to protect its fruits, the lower leaves are sharp serrated and very piercing. The upper leaves are simple. So, the lower leaves protect the ripe fruits and buds against herbivores like deer or boars.
On the other hand, the upper regions of I. aquifolium are a very popular nesting site for small bird, because here their nests are protected against predators (e. g. Foxes or bobcats).

I. aquifolium is dioecious, so we have male and female individuals. The small flowers have five petals and five sepals (sometimes six). The petals are white, sometimes reddish. Flowering Time is between May and June.

I. aquifolium - berries & leaves

The ripe fruits are red berries. They are very poisonous and cause vomiting, kidney damage and cardiac arrhythmia. This also applies to the leaves. Fruit Ripening is from October.
 
I. aquifolium is native to the oceanic and temperate regions of Middle Europe like France, England and Western Germany.
So, it's a good indicator for the Atlantic climate. The species prefers fresh places with temperate winters and loamy, acid soils on sand or rock. It can be found as shrub in forests, because it's very tolerant towards shading.
However, many individuals are also planted in Parks or gardens.