Botany

Micrasterias
fimbriata

BA410

PlanFluar 10x

Moticam 10
Botany

Crystals in
Larix decidua

BA410E

PlanApo 40x
pol. lam.

Moticam 10 stack
Zoology

Parnassius apollo
part of wing

BA310E

PlanApo 20x

Moticam 10 stack
Histology

Femur cross
section

BA310E

PlanApo 20x

Moticam 10
Pathology

Haemolysis
streptococcus
sepsis

BA410

PlanAchro 100x o.i.

Moticam 5
Microbiology

Onion mitosis

BA410 

PlanAchro 60x

Moticam 5
Zoology

Barnacle on
mussel

SMZ-171

Stereo

Moticam 10 stack
General

Tumbled gems

SMZ-171

Stereo

Moticam 10 stack
Pathology

Eimeria stiedae
in liver

BA410 
PlanFluar 20x

Moticam 10
Microbiology

Penicillium with
conidiophores

BA310E

PlanApo

Moticam 10
Histology

Artery

BA410

PlanAchro 10X

Moticam 5
General

Urea crystals

BA410

PlanFluar 20x
pol lam

Moticam 10

When leaves are falling

  • 1 Premature defoliation SMZ-171 Moticam 10
  • 2 Premature defoliation detail BA410E PlanApo20X Moticam 10

Premature defoliation at the base of the leafstalk or petiole. Damage from road salt (ions)

The images show the prepairation of the cleavage of tissue at the base of the petiole. During the perspiration, ions, which are introduced via the roots, constantly remain behind in the leave tissue, which accumulate over time to such an extent, that they slow down the photosynthesis. In addition, the water supply in freezing weather becomes so difficult, that the perspiration has to be greatly reduced. Therefore, our deciduous trees shed their leaves in autumn or sooner, also depending on the amount of accumulated ions. This is an active, hormonally controlled process, which takes place in a separating layer consisting of multiple layers of parenchyma cells, at the base of the petiole. There, several enzymes dissolve either the middle lamellae alone, or together with the primary walls or the entire cells. Then the vascular bundles tear off, and the leaf can drop. As the images show, the point of attachment of the petiole is protected from dehydration and infection, by a layer of cork, which has already been laid out before the leaf falls.


Tar spot (Rhytisma acerinum)

  • Tar spot ba410eplap20Xmot10

The microscopic image shows an infected leaf with sclerotia. A consequence of monoculture.

Just like buildup of mold on pine needles and on the leaves of the willow, an ascomycete (Rhytisma) is the cause of tar spot. From late summer to autumn, round black mold deposits are growing on the leaves of several species of maple, which overwinter on the ground after the falling of the leaves. In spring distribution follows via the light and far away floating mold spores. If  maples are standing close together in species-poor mixed forests, the fungus can spread excessively. The photosynthesis of infected leaves is severely hampered by the non-translucent mold deposits. The consequences are that the formation of wood will slow down and that the tree will weaken. The parasitic ascomycete gets its energy from the vascular bundles of the leaf, via its string-like hyphae, which can be recognized in the cross section of an affected leaf.

f161
Formation of black spots on maple leaves in autumn.

Mold class: Ascomycetes
Sclerotia: Hardened form of tissue


A bio-indicator for air pollution

  • healthy lichen BA410EPlanApo20X
  • Damaged lichen BA410EPLanApo20X

Growth of lichens on trees: Bio-indicator for clean and contaminated air. Lichens are dual beings, developed from a symbiosis of algae and tiny fungi. Fungi and algae alone are dependent on moisture. As a community, however, they prefer dry places. Because of the slow growth and the great loyalty to their habitat, no other group of plants is so suitable to display properties of permanent locations. Lichens are highly sensitive biological indicators of changes in conditions of a habitat. By aggressive air constituents such as nitrogen oxides and heavy metals, lichens stock is destroyed gradually.

The community life of fungi and algae in need of moisture, protects itself against evaporation and radiation of sunlight by special provisions of the supporting tissue. By aggressive air constituents such as nitrogen oxides and heavy metals, this protective features of lichens are destroyed. Photosynthesis in the symbiotic algae is significantly impeded. The result is a slow dehydration and destruction of the lichen. Although many species of lichens can live under extreme conditions (well below -20 °C and at temperatures above +70 °C), some species react particularly sensitively to pollutants in the air. Therefore they are considered as so-called bio-indicators of contaminated air. As long as these kinds of lichens occur frequently on trees or woodland, this indicates no or little contaminated air. Some lichens would be able to reach an age of more than 100 years. Lichens are characterized by a very wide variety of shapes and colors.



A cactus takes breath at night

  • Crystals in cactus

A cactus takes breath at night Most plants have their pores (stomata’s) open during the day to take in carbon dioxide, and usesunlight as a catalyst for the photosynthesis. But in thedesert, plants with pores open during thehot days, lose much water through evapotranspiration. So, succulents use a modified version ofphotosynthesis called CAM (Crassulacean Acid Metabolism). CAM plants open their stomata’sonly at night when it is cooler so there is less evapotranspiration. Because there is no sunlight toact as a catalyst, carbon dioxide is stored as an organicacid, principally Malic Acid (C4H6O5).

Carbon dioxide is gradually released from the acid during the next day. CAM plants use aboutone-tenth the water to produce each unit of carbohydrate compared to standard photosynthesis.The price: a much slower growth rate. Many plants contain malic acid, but usually in lesserquantities than found in cacti. Besides malic acid, succulents produce oxalic acid(C2H2O4),which is toxic, as another product of photosynthesis.“Its chief function seems to besequestering metals, principally calcium. Calcium oxalatesoften occur as crystalline mineralswithin the cactus pulp. Their function seems to be aiding structural integrity and enzymaticprocesses.

In fact two crystalline calcium oxalate mineralshave been identified in all cactitested: CaC2O4.2H2O (weddellite) and CaC2O4.H2O (whewellite).”Oxalates are also formedwith heavy metals such as copper, perhaps to reduce toxicity to the plant.


Pollen give honey its fingerprint

  • Pollen of Lilium sp BA410EPlanApo20XMot10stk

Bees collect pollen from flowers and trees. They carry them along as yellow balls at their  legs. The  granules  (also  known  as  pollen)  are  not  only  of  vital  importance  for  the  bees,  the  unique mixture also contains very useful substances for man.

An  important  element  of  honey  research  is  pollen  analysis.  Under  the  microscope it  can  be determined  precisely,  which  are  the carrying  plants  of  the  pollen  and  from  which  region  they originate. Both the botanical and the geographical origin of the honey is  determined. The work of the beekeeper can also be reviewed and monitored on manipulation of honey, such as honey filtration or addition of pollen.

Due to the too low concentration of pollen in honey, the first step is concentration in order to be able  to  examine  it  under  the  microscope.  Pollen  can  be isolated  from  honey  by  centrifuging  a dilute  solution  of  honey  in  water.  A  small  amount  of  the  pollen  residue  is  transferred  with  a pipette  to  a  microscope  slide  and  then  carefully  dried  at  40  degrees  Celsius.  After  drying,  the pollen  residue  is  embedded in  glycerin  gelatin  to  which,  if  necessary,  basic  fuchsin  can  be added  as  a  coloring  agent.  This  makes  structures  come  out  more  clearly.  After  placing  the coverslip, the kind of pollen can be determined with the aid of a microscope, by comparing the microscopic image with illustrations, descriptions or preferably with a reference collection.

The annual rings of a tree trunk tell us a lot

  • wood wide planapo 4x mot10
  • Wood narrow planapo 4x mot10

The  wood  of  deciduous  trees  contains  numerous  tracheae  with  large  lumens, present  in  the annual  rings.  They  are  there  for  the  water  and  fluid transport  which  is  increasing  during  the growing  season,  because  leaves,  having  a  larger  surface area,  evaporate  considerably  more water  than  for  example  the  needles  of  conifers. In  the  microscopic  image,  the  regular arrangement of the early wood with wide  lumina and that of the late wood with small lumina is striking.

Cambium is formed by the layer of cells in the stem that are capable of cell division. The ability to    grow of  the  cambium  is  stopped  in  late  summer.  This  creates  growth  rings  as  boundaries between the dark late wood of the previous year and the bright newly formed early wood. The
early  wood  is  growing  faster  than  the  late  wood  and  it  therefore  forms  a  broader  zone  of relatively large cells. The late wood, however, forms a narrow zone of smaller, thick-walled fiber cells. These two differently colored and unequally wide zones, form the increase of wood in the
stem, within a year; the so called annual ring. On the basis of the annual rings, the age of a tree can thus be read out.

The  cross  section  in  the  first  image  shows  wide  annual  rings  created  by  normal  growth.  The cross section in the second image shows narrow annual rings caused by drought.

Note: Cambium:  in  plants, a layer  of  actively  dividing  cells  between  the  xylem  (wood)  and  phloem  (bast)  tissues,  that  is responsible for the secondary growth of stems and roots (secondary growth occurs after the first season and results in increase in thickness)

Rheinberg illumination

  • Diatom BA310E BF 40X Moticam 10 Rheinberg green blue
An interesting variance of darkfield is Rheinberg illumination, discovered in 1896 in London by Julius Rheinberg. The major difference between darkfield and Rheinberg illumination is color. Whereas in darkfield, the background is black and the subject is white, Rheinberg goes a step further and creates a colored background and a colored subject.

The condenser in a brightfield microscope illuminates the specimen with a solid cone of light. There are some simple additions that can be made to even inexpensive microscopes that dramatically enhance the image by manipulating the way light hits the specimen. These methods are best accomplished using low power objectives (4X to 20X)

Darkfield illumination involves the use of a special darkfield condenser or the use of a patch stop of black paper centered on a round, clear acetate disk placed in the filter holder of an Abbe condenser. The latter, of course, is the cheapest way to achieve darkfield conditions, especially with 4X to 20X objectives. High-power objectives, such as 40X, 60X and 100X oil immersion, really require the use of special darkfield condensers to be fully effective.

The simplest form of Rheinberg illumination involves a central stop which is made of a colored translucent material, the image background becomes the color of that material. By adding other colors to the outer cone, different objects refract those different colors. The condenser diaphragm should be wide open and the unit racked all the way up. But the condenser can be slightly raised or lowered for the best effect.

The colored filter materials are readily available from craft and art stores and can produce impressive effects as illustrated with this image of a diatom. This technique also gives the impression of depth in the image.


Glittering crystals in the wood of larix decidua

  • Crystals BA410E PlanApo
Linearly polarized light or planar polarized light, is polarized light that consists of light waves that vibrate only in one direction (or in other words, only in one plane) In nature it is the most common kind of polarized light. Linearly polarized light occurs, for example, by scattering of light in the atmosphere or by reflection of light on a water surface. Linearly polarized light is used in the optics in polarization microscopes.

A polarizing microscope is a microscope wherein the object is located in the optical path between two polarizing filters. It is thus illuminated, or irradiated with polarized light. In the optical system of the microscope also a rotatable polarizing filter is included. If the object itself rotates the polarization direction of the light, this can be detected by the microscopist. If he puts the two polarization filters in a crossed state with each other, then normally no more light will be transmitted from the light source to the eye, except when the object itself is optically active, then it will light up clearly, sometimes in striking rainbow colors. This is of particular importance in distinguishing different crystals and minerals.


A japanese woodblock print?

  • Antithamnion plumula Hgld BA410E planapo 40x stk
  • Antithamnion Plumula Helgoland BA410 BFF10X Moticam10

Red algae such as Antithamnion plumula are considered primitive algae. The red algae are classified in the division Rhodophyta, which consists of predominantly marine algae that are often found attached to coastal rocks. This sample has been obtained during an environmental study near the island of Helgoland in the North Sea in June 1995.


Who eats banana stems?

  • Banana stem BA410 BFF obj 10X Moticam 10

The banana tree is one of those few species where each part is used in some way or the other, be it the leaves which are used for eating food, the fruit which is eaten in the raw or ripe form, or the flower or stem which is also consumed.

Banana stem can be cooked or consumed raw in juice form. The stem is cooked in various ways in South Indian cuisine and in some parts of West Bengal. Banana stem is a rich source of fiber and helps in weight loss. Its high fiber content creates a feeling of satisfation and hence, reduces the intake of food. It also helps ease constipation. Banana stem is rich in potassium and vitamin B6 just like the fruit. Vitamin B6 helps in production of hemoglobin and insulin. Again, it improves the ability of the body to fight infection. Potassium helps in the proper functioning of muscles, including the cardiac muscles. It also helps prevent high blood pressure, and maintain fluid balance within the body. Banana stem is said to be a diuretic and helps detoxify the body. It is used prevent and treat kidney stones.
Source: The Hindu


 

Living apart together

  • Volvox BA410BFF20Xstack

Volvox Aureus is a Chlorophyte, or green alga. It exists as a grand spherical colony. Each little alga within the colony bears two flagella, whip-like hairs. The individual algae are connected to each other by thin strands of cytoplasm that enable the whole colony to swim in a coordinated fashion. The individual algae also have small red eye spots.

The colonies even have what we could call a front and rear end. Or, since Volvox resembles a little planet, a 'north and south pole'. In the northern region the eyespots are more developed. This helps the colony to swim towards the light. This differentiation of cells makes Volvox quite unique. It is a colony that comes really close to being a multi-celled organism.

Watching groups of colonies under the light microscope is a breathtaking sight. If you leave enough space under the cover slip (with the aid of spots of Vaseline under the corners) the spheres will swim slowly towards the light of the microscope, (use dark field illumination!).
Source: Microscopy.UK


 

DoddDodder, a spiraling parasite

  • Cuscuta dodder on host BF10xMot5
Dodder (Cuscuta and Grammica), is a twining yellow or orange plant sometimes tinged with purple or red. Occasionally it is almost white. Dodder can be identified by its thin stems appearing leafless, with the leaves reduced to minute scales.
Dodder is classified as a member of the Morning-Glory Family (Convolvulaceae) in older references, and as a member of the Dodder Family (Cuscutaceae) in the more recent publications. Dodder parasitizes various kinds of wild and cultivated plants, and is especially destructive to alfalfa, lespedeza, flax, clover and potatoes. Ornamentals attacked included chrysanthemum, dahlia, helenium, Virginia-creeper, trumpet-vine, English ivy and petunias.
The seedlings must attach to a suitable host within a few days of germinating or they die. Once the Dodder seedling finds a host plant, it quickly twines itself around the plant's stem. Dodder always twines in a counter-clockwise direction. Next, Dodder will lose its connection to the ground. It now totally depends upon its host. The basal part of the parasite soon shrivels away so that no soil connection exists.  Its water, minerals and carbohydrates are absorbed from the host through haustoria that press up against the stem of the host plant and penetrate the tissue. In dodder the haustoria are modified adventitious roots. Dodder rarely kills its host plant, although it will stunt its growth.
The flowers are numerous, white, pink or yellowish, small (2 to 4 mm long depending on species), and can be borne in tight balls or in a loose cluster (again depending on species). Flowers normally appear from early June to the end of the growing season. The fruit is about 3 mm in diameter, with thin papery walls and contain 1 to 4 seeds. The seeds are yellow to brown or black, nearly round and have a fine rough surface with one round and two flat sides. These seeds drop to the ground and germinate the next growing season if a suitable host is present. If no suitable host is present, the seed may remain dormant for five years.


 

Fragilaria, a fragile kind of diatom

  • Fragilaria spBF 40X stack

Fragilaria is a genus of diatoms (Bacillariophyta) with about 100 species found in freshwater and seawater. It is often abundant in the plankton of lakes. Fragilaria crotonensis (like Astrionellla Formosa) is a species that is considered to have a worldwide distribution and is also considered to be introduced by human activities. The cells in Fragilaria are arranged in flat, linear tapes which are often rotated in its longitudinal axis. The individual cells have the typical diatom shell of two covers. This is rectangular in side view, in shell view it is rod-shaped. The cells have a central nucleus and two plastids that are under the shell surface, and are colored golden brown by fucoxanthin. The plastids contain several pyrenoids. Some species have more than one disc-shaped plastid. Since the cells in the tapes are always connected to each other by the shell surfaces, the side view will be seen almost always. Asexual reproduction occurs by the typical dichotomy of diatoms, which leads to the extension of the tape. The tape can also break. The formation of spores is known, whether they are formed through sexual reproduction is not known. The variability of the species results from different cell sizes, different length to width ratios of the cells in side view and the shape of the cells in the shell view.


 

Desmids, beauties in microscopy

  • Micrasterias fimbriata BA410BFF10XMot10
This photomicrograph shows Micrasterias fimbriata, a type of green alga called a desmid. Micrasterias  fimbriata  belongs  to  one  of  the  rare  desmids  of  the  Lowlands.  This  one  was recently found in a fen in the north of Belgium. Micrasterias is named from the Greek mikros,"small" plus aster, "star".

Desmids  usually  inhabit  the  acidic  waters  associated  with  sphagnum  (peat)  bogs.  These particular  desmids are flat,  plate-like  single cells  made  up  of  two  halves  (semicells),  which are mirror images of each other with highly ornamented edges. The two semicells are joined by a narrow central bridge, or isthmus, containing the nucleus where the organism's genetic material is held. 

Micrasterias  sp.  can  reproduce  asexually  by  binary fission  (resulting  in  two  separate  cells, each of which has one of the parent's semi cells and one new semicell). During this process, genetic material is duplicated and two new semi cells grow between the original semi cells. Micrasterias  can  also  reproduce  sexually  through  a process  known  as  conjugation,  which involves the transfer of genetic material between two cells.


 

Iris germanica, leaf of a monocotyledon plant, cross section

  • Iris leaf c.s. BA410BFF10XMot10
The leaf of the Iris Germanica is unifacial in its upper part, this means that both sides are equal.  Its  lower part however  becomes  increasingly bifacial;  the  opposite  sides  resemble each other increasingly less. Both sides of the leaf have the same number of stomata, being an  indicator  for  unifacial  leaves.  A  "cap"  of  sclerenchyma  fibers  closes  in  to  the  phloem vessels at the outside. It protects and gives the leave tensile and tear strength at the same time. Vascular bundles are leaf veins. The Iris germanica can be recognized as a monocot by their parallel veined leaves.

Iris is a genus of 260–300 species of flowering plants with showy flowers. It takes its name from  the  Greek  word  for  a  rainbow,  referring  to  the  wide  variety  of  flower  colours  found among the many species. As well as being the scientific name, iris is also very widely used as a common name for all Iris species, as well as some belonging to other closely related genera.  A  common  name  for  some  species  is  'flags', while  the  plants  of  the  subgenus Scorpiris are widely known as 'junos', particularly in horticulture. It is a popular garden flower.

Iris leaves are inwardly folded along the edges serving as sheaths helping to keep the leaves firmly together. Most plants belonging to the Iris genus usually produce flat, lance-like leaves.


Too many mouths?

  • Stomata Vicia Faba Leaf
Stomata,  are  the  mouths  of  plants.  Plants  breathe  through them,  just  as  we  do  with  our lungs. They are not visible to the naked eye, and a plant therefore needs quite a lot of them. However, there must be some space between the stomata, otherwise they  cannot open and close  properly.  How  many  stomata  a  plant  makes  is  dependent  on  the  presence  of  the protein  Too  Many  Mouths  (TMM,  'Too  Many  Mouths’)  This  protein  is  so  named  because  a plant is going to make too many stomata in the absence thereof.

Stomata are not only the "lung"  of plants, they also play  an important role in the evaporation of  moisture.  When  stomata  are  open,  a  plant  evaporates  lots  of  water.  Plants  have  to  be careful that they  do not make too little, but also not too  many stomata. If they make too little then  they  cannot  bring  in  enough  carbon  dioxide  for  photosynthesis.  And  if  they  have  too much of them, they run the risk that they will dry out quickly when opening up their mouths.


Workhorse Aspergillus Niger

  • Aspergillus Niger BA410 BF obj. 40X Moticam 2500
Aspergillus  Niger  is  a  fungus  and  one  of  the  most  common  species  of the  genus Aspergillus. It causes a disease called black mold on certain fruits and vegetables such as grapes, onions, and peanuts, and is a common contaminant of food. It is ubiquitous in soil and  is  commonly  reported  from  indoor  environments, where  its  black  colonies  can  be confused with those of Stachybotrys (species of which have also been called "black mold")

Aspergillus Niger represents the most efficient, highest yielding bioprocess for the production of citric acid in practice. This process is a model for other filamentous fungal fermentation processes for the production of multiple products such as organic acids and ethanol, from renewable biomass. These products can be further refined for use as plastic monomers, solvents, or fuels, thereby decreasing dependence on petroleum, the traditional source of these products.

As a common member of the microbial communities found in soils, A. Niger also plays a significant role in the global carbon cycle. It is a soil saprobe with a wide array of hydrolytic and  oxidative  enzymes  involved  in  the  breakdown  of plant  lignocellulose.  An  increased understanding of the molecular mechanisms controlling carbon flux in fungi will be gained from study of the A. Niger genome. Finally, A. niger is an important model fungus for the study of eukaryotic protein secretion in general, the effects of various environmental factors on suppressing or triggering the export of various biomass degrading enzymes, molecular mechanisms critical to fermentation process development, and mechanisms involved in the control of fungal morphology.

Sources: Wikipedia, JGI Joint Genome Institute


Algae have sex too!

  • Spirogyra vegetativ BA410 BF obj. 20X Moticam 2500
  • Spirogyra conjugatiion BA410 BF obj. 20X Moticam 2500
Algae have sex too! (at least some of them, though who knows if they enjoy it?) Amongst the Zygnemaceae, the process of conjugation consists of the joining together of the contents of two haploid cells from (usually) different filaments.

Conjugation in Spirogyra: the filaments show the typical results of scalariform ('ladderlike') conjugation. Two filaments lie parallel, and outgrowths from each filament grow towards each other, and then fuse to form a conjugation tube. The conjugation tubes allow the contents of one cell to transfer to the other. The dark oval shapes are diploid zygospores, formed after nuclear  fusion  between  the  two  haploid  cells.  They form  in  only  one  of  the  two  filaments. Sometimes more than two filaments take part in conjugation like a 'menage a trois'.

Spirogyra  is  a  filamentous  green  alga  in  which  the  chloroplast  has  a  characteristic  spiral shape. In one of the photographs, you can see the chloroplast coiling against the outer edge of  the  cells.  The  numerous  small  round  blobs  along the  edges  of  the  chloroplast  are  the pyrenoids. The larger, faint blobs (they look like out-of-focus regions) that take up most of the volume of the cells in the filaments on the right are the nuclei, which are suspended in the interior of the cells.

Pyrenoids  occur  in  many  of  the  algae  and  are  associated  with  the  chloroplasts.  Some  of them are known to contain Rubisco, the enzyme that catalyzes the incorporation of inorganic CO2  into  carbohydrate  (Graham  and  Wilcox,  2000).  In  these  algae,  pyrenoids  probably function  to  fix  carbon.  In  other  algae,  pyrenoids  are  the  sites  of  carbohydrate  (typically starch) storage. Starch and iodine  react to produce  a  deep  blue- black color, so  staining  a thin algal prep with iodine will indicate the presence of pyrenoids.

Sources: Algalweb, MadSci Network


Small is beautiful

  • Rosette BA410 BFF obj. 40X Moticam 10 stack
  • Rosette BA410 BFF obj.10X Moticam 10

Diatoms, exhibition mount by Klaus Kemp (UK) The fine glassy details of diatoms are admired already for hundreds of years, ever since the invention  of  the  microscope.  During  Victorian  times,  manipulation  and  studying  of  diatoms was considered an art and a pastime, and slides with different species of diatoms were used to thoroughly evaluate the latest microscope objectives for performance.

The diatoms are one of the largest and ecologically most significant groups of organisms on earth.   They   are   also   one   of   the   easiest   to   recognize,   because   of   their   unique   cell structure, silicified cell wall and life cycle. They occur almost everywhere that is adequately lit (because most species need light for photosynthesis) and wet - in oceans, lakes and rivers; marshes,  fens  and  bogs;  damp  moss  and  rock  faces;  even  on  the  feathers  of  some  diving birds.  Some  have  been  captured  by  other  organisms  and  live  as  endosymbionts,  e.g.  in dinoflagellates and foraminifera.  Because of their abundance in  marine plankton, especially in nutrient-rich areas of the world's oceans, diatoms probably account for as much as 20% of global  photosynthetic  fixation  of  carbon,  which  is more  than  the  entire  world's  tropical rainforests


Algae in all colors of the rainbow

  • Batrachospermum BA410 BF obj. 4X Moticam 2500
  • Batrachospermum BA410 BFF obj. 40X Moticam 2500 stack
  • Batrachospermum BF obj. 10X Moticam 2500
Algae appear in all colors of the rainbow; green, yellow, blue-green, red and so on. When it comes to freshwater algae, red is rare. Fortunately, the red algae, or Rhodophyta, are well represented by a very common genus, Batrachospermum, which includes quite a number of species. Batrachospermum, is a genus of freshwater red algae ranging in colour from violet  to  blue-green.  The  long,  branched,  threadlike  filaments  bear  dense  whorls  of branchlets, resembling beads on a string. Spores are formed in clusters around the base of the carpogonium (female sex organ) after fertilization. The genus is found in streams and in pools in sphagnum bogs. From shore, the Batrachospermum thallus looks almost black.