Milkweed

We were driving from Ottawa to Montreal on a late October (2013) Sunday when I noticed cottony looking plants along the highway. We pulled over and I collected a few stems with the dry, half open seed pots attached. I took their photographs when we reached home. What beautiful images I had! When I looked it up I found out that this was milkweed. Had I not first seen  it in its  dry state, I would not have noticed milkweed and learned about it. This was my first discovery of a native Canadian plant.

Commonly known as milkweed or silkweed, Asclepias syriaca is native to Southern Canada and much of the conterminous (having a common border-I learned a new word) U.S. east of the Rocky Mountains. Too bad the species name is Syriaca meaning ‘of Syria’ which it is not. Carl Linneaus or Carl von Linné, as he was known later, named it in the mid-1700s but he confused it with the milkweed from the Orient. In botany, a name first assigned is unchangeable, regardless of errors in derivation or spelling.

A. syriaca is in the milkweed subfamily Asclepiadoideae (formerly in the family Asclepiadace) of the family Apocynaceae. Asclepias comes from Asklepios, the Greek god of medicine, for the medicinal properties of the plant.

A. syriaca is a species of flowering perennial herb. It grows in sandy soils and other kinds of soils in sunny areas starting from a rhizome and reaches a height of 60 to 120 cm. It was one of the earliest North American species described in the French physician and botanist Jacques-Philippe Cornut’s (1606-1651) 1635 work Canadensium Plantarum Historia.

Milkweed flowers bloom from June to August. The fragrant, nectariferous-nectar producing flowers occur in compound cymes. The flowers have five petals and they are rose to purple in color. Individual flowers are about 1 cm in diameter.

compound cyme


The leaves are broad, elliptical and opposite. The large leaves have very short petioles (the stalk by which the leaf is attached to a stem) and velvety undersides.

The fruit are green pods or follicles which turn brown before bursting open to let out beautiful fluffy seeds like the ones that drew my attention.

In late summer and early fall the seed pods mature and dry out, they crack open and release many disc shaped brown seeds borne by the wind on a plume of white silky hairs. The seeds are neatly packed in overlapping rows. One name for the filament like hairs they are attached to is pappus. The name pappus derives from the Greek word pappos, Latin pappus, meaning ‘old man’.

The pappus function as a ‘parachute’ which enables the seed to be carried by the wind.


                                

The leaves of the milkweed are the only food source for the Monarch butterfly larvae (caterpillars). Milkweed flowers are a nectar source for many butterflies but especially the Monarchs. Without milkweed we would not have these beautiful butterflies.

 Photograph: Aydın Örstan, Monarch butterfly at Black Hill Regional Park, 20930 Lake Ridge Drive, Boyds, Maryland, USA
 
I am learning that milkweed is also an important nectar source for many species of insects such as the native bees, wasps, and other nectar-seeking insects. The plant is a food source for a variety of herbivorous insects, including numerous beetles and moths, specialized to feed on the plant despite its chemical defenses. Milkweeds are a shelter and hiding place for other species as well. Yellow Jacket wasps eat bees and flies which get trapped in the flowers, and crab spiders ambush tasty visitors. Milkweed Bugs, and Milkweed Leaf Beetles only eat milkweed, and could not survive without it.

Yet, the plant is on Ontario’s noxious weeds list. All parts of the milkweed plant produce white latex when broken. The sap has poisons in it, called cardiac glycosides. These are similar to digitalis or digoxin, common heart medications used in both human and veterinary medicine. Consumed in large quantities milkweed has poisoned livestock.

Some animals can eat the glycosides and not be harmed. The Monarch butterfly caterpillars eat the leaves of milkweed and store its toxic compounds, which makes them unpalatable to predators. Even after the caterpillars change into adult butterflies, they keep the glycosides in their body.

       

Jack Sanders, author of the book titled The Secrets of Wildflowers (2003) provides interesting information on milkweed. He also shares my feelings of joy and amazement. He writes: “Milkweeds are among the great toys of nature, known to almost any kid who grows up in the country.” He quotes naturalist F. Schuyler Mathew (1894): “The common milkweed needs no introduction. Its pretty pods are familiar to every child, who treasures them until the time comes when the place in which they are stowed away is one mass of bewildering, unmanageable fluff.”

I could easily be that child had I known milkweed seeds.

To give nature a hand, milkweeds can be propagated from seeds, cuttings, and, in some cases, from root divisions.

Shepherd's purse

I love the design of this plant.

Capsella bursa-pastoris, known by its common name shepherd's purse because of its triangular, purse-like pods, is a small, annual and ruderal (first to colonize disturbed lands) species. It is a member of the Brassicaceae or mustard family. It is native to Eastern Europe and Asia Minor that is Turkey. It is also naturalized and considered a common weed in many parts of the world such as Britain, North America, China and also in the Mediterranean and North Africa.

C. bursa-pastoris is used as a model organism due to the variety of genes expressed throughout its life cycle. Wikipedia informs us that a model organism is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the organism model will provide insight into the workings of other organisms.

Unlike most flowering plants, it flowers almost all year round. Like many other annual ruderals C. bursa-pastoris reproduces entirely from seed, has a long soil seed bank and short generation time. It is capable of producing several generations each year.

I found the one I photograph in Montreal, along a sidewalk, as I was walking to a store.

C. bursa-pastoris plants grow from a rosette of lobed leaves at the base.

From the base emerges a stem about 20 to 50 cm tall, which bears a few pointed leaves. The flowers are white and small, in loose racemes, and produce seed pods which are heart-shaped.

Like a number of other plants in several plant families, its seeds contain a substance known as mucilage. The fact that mucilage becomes sticky when wet has led to the thought that perhaps C. bursa-pastoris traps insects which then provide nutrients to the seedling, which would quite interestingly make it proto carnivorous.

Johann Georg Sturm (Painter: Jacob Sturm) - Figure from Deutschlands Flora in Abbildungen at http://www.biolib.de

                                      

Capsella bursa-pastoris is a lovely familiar plant of mine that I enjoy seeing very much.

Muşmula

All these years I’ve been eating muşmula, medlar in English, I thought I was eating ripe medlar. I did not know that medlar is bletted. Bletting is a process that certain fleshy fruits undergo which takes them to a point beyond ripening. As I was writing this post, I found out that unbletted medlar is utterly tart and very unpleasant, rather inedible. Eating bletted medlar, on the other hand, is an acquired taste. It is like eating a tart, brown and pasty spread all the while manipulating five big pits in your mouth. Unless you grow up eating this fruit, maybe even then, it does not come easy to acquire a taste for it. Personally, I love the taste and the texture.

Cross section of unripe and bletted Mespilus germanica

http://commons.wikimedia.org/wiki/File:Mespilus_germanica_01.jpg Author: Takk, picture taken November 1, 2008

                            
                                                                                              Bletting has just begun in one corner.

The fruit is picked in the autumn when the leaves start to fall off the tree. It is recommended to pick them right after the first frost, when they are still hard. The frost is said to help improve the flavor. At this stage, they are both too sour and too hard to eat. The fruit needs to be bletted. The medlars are spread on some type of absorptive material such as straw, sawdust, or bran somewhere cool, and allowed to ripen for several weeks. They will become soft, mushy, brown, sweet and tasty with a flavor close to applesauce or cider.

In Trees and Shrubs, horticulturist F. A. Bush wrote that “if the fruit is wanted it should be left on the tree until late October and stored until it appears in the first stages of decay; then it is ready for eating.” With global warming there is never any frost until well into November these days. I have bought medlars in the first stages of decay and it doesn’t work, they never reach the desirable stage of bletting in the kitchen.

Mespilus is a genus of two species of flowering plants in the family Rosaceae. The one I know, Mespilus germanica (syn. Crataegus germanica), despite its Latin name which means German or Germanic, medlar is indigenous to southwest Asia and also southeastern Europe, especially the Black Sea coasts of Bulgaria and of modern Turkey. The other medlar, Mespilus canescens, was discovered in North America in 1990.

Mespilus germanica, a large shrub or a small tree the fruit of which carries the same name, has an ancient history of cultivation and wild plants exist in a much wider area; it was grown by the ancient Greeks and Romans.

http://en.wikipedia.org/wiki/Mespilus_germanica#mediaviewer/File:Illustration_Mespilus_germanica0.jpg

Describing someone as medlar faced-‘muşmula suratlı’ in Turkish-means that the person has a permanently sour expression. Perhaps it drives from the fact that while eating medlar one must inevitably make faces.

Ecballium elaterium

I do not see this plant very often but each time I come across it, the child in me that likened it to old perfume atomizers comes back to me.

Do you see a resemblance?

When I decided to look up Ecballium elaterium and write about it, I did not know anything factual about this Mediterranean plant native to Europe, northern Africa and temperate areas of Asia. Also called the squirting cucumber or exploding cucumber, it is a perennial herb in the family Cucurbitaceae, the cucumber family. It is the only species in the genus.

The common name comes from the fact that, when ripe, the knobby fruit which is the size of a small chicken egg and covered with numerous glandular hairs arranged in rows, squirts a stream of mucilaginous liquid containing its seeds, which can be seen with the naked eye. Mucilage is a thick, gluey substance produced by nearly all plants and some microorganisms. Mucilage in plants plays a role in the storage of water and food, seed germination, and for thickening membranes.

The seeds of E. elaterium are black and ovoid. The pressure inside the fruit that houses them is so high that when the fruit is ripe the seeds are said to be ejected even with the slightest brush by a passerby. Bar is a metric unit of pressure equal to the atmospheric pressure at sea level on earth. The pressure in the E. elaterium fruit is bar 6 and this can translate to a 36 km/h force when a hole appears where the fruit is attached to the stem and the poisonous juice that stings the skin is spread out noisily. The seeds are projected 4-6 m from the plant.

All parts of the squirting cucumber are toxic, particularly the oval green fruits.

The plant, and especially its fruit contains cucurbitacins. Cucurbitacin is any of a class of biochemical compounds that some plants-notably members of the family Cucurbitaceae, which includes the common pumpkins and gourds-produce and which function as a defence against herbivores.

The cucurbitacin that is a greenish substance extracted from the juice of the fruit of E. elaterium is called elaterium or elaterin and it has numerous medicinal uses.

The ancient Egyptians, Greeks and Romans used it as a remedy for intestinal ailments. The names of many historical medical figures are associated with the plant. Hippocrates, Dioscorides, Ibn Sina, later Mattioli, Lonicerus and more found medicinal uses for the plant.

In Turkey, the fresh fruit juice of this plant is said to be used by direct application into the nostrils as an anti-inflammatory and analgesic herbal medicine for the treatment of chronic sinusitis. It must never be used without consulting a doctor for its use may easily cause damage to the mucus membranes.

In the ancient world the juice of the plant was also considered an abortifacient.

The extraction from the roots is said to possess remedial properties for the relief of rheumatoid aches and pains.

Elaterium or elaterin is also used as a purgative. It has been found to decrease the damage caused by chronic hepatitis. Plenty more medicinal uses are named for this plant.

E. elaterium flowers through the months of June to September. The plant has small light yellow flowers. The fruit is picked when it is still not fully ripe from August to October. The sap from the fruit is sold fresh. Otherwise the fruit is dried.

Drying must take place in well aerated buildings or in ovens at 45˚C. On average, 1 kg of dried fruit is obtained from about 12 kg of fresh fruit.