Monday, January 30, 2012

The Indian Date

Tamarind tree
Tamarindus indica (Tamarind)
The Tamarind tree is little known in the west, but common in Africa and Asia. It name comes from the Arabic and Hebrew words tamar , which means "date", and hind, which means "India". Its fruit can be eaten, turned into a drink, or used to flavor ice cream. Both its fruit and bark are used in traditional medicines and modern studies have shown that they contain chemicals that can work as anitibiotics. In Asian temples, the fruit pulp is used to polish brass Buddhas.

Thursday, January 26, 2012

Marijuana's tough cousin (or, A Very Strong Weed)

Cannabis sativa 001
Cannabis sativa L. subsp. sativa (hemp)
Hemp (Cannabis sativa L. subsp. sativa) has been cultivated for thousands of years. Its stalks yield high quality fibers which are used in ropes, clothing, paper, and sails. The word "canvas" is derived from the Latin name cannabis. Of course many of us are more familiar with hemp's very close cousin, Cannabis sativa L. subsp. indica, better known as marijuana. Hemp and marijuana are essentially the same plant, with the former having been bred for strong fibers, while the latter was bred for high THC content. Marijuana yields low quality fibers, while you'd have to smoke kilograms of hemp to get a high.

Monday, January 23, 2012

Yew and cancer

PacificYew 8544
Taxus brevifolia (Pacific Yew)
The Pacific Yew is a conifer found primarily in the Pacific Northwest. Its thin scaly back would probably go unnoticed if not for the fact that it contains a chemical called paclitaxel, or more commonly known as the chemotherapy drug Taxol. Taxol was discovered in the mid 1960s as part of a large-scale program to identify natural products which might be used against cancer. In 1992 Taxol was approved by the FDA for use in fighting breast, ovarian and lung (and a few other) cancers. This is a prime example of how a deep knowledge of biodiversity can lead to incredibly important applications.

Saturday, January 21, 2012

A fractal vegetable

Fractal Broccoli
Brassica oleracea 
Romanesco broccoli resembles cauliflower, but with two important differences: First its maintains broccoli's light green color. Second and most amazingly, Romanesco broccoli organizes into a natural fractal. Its myriad buds (the small bumps on the top of cauliflower and broccoli) self-organize into a repeating logarithmic spiral, which results in an enticing vegetable, almost to beautiful to eat! Each of the buds is a potential flower which doesn't fully develop.

Wednesday, January 18, 2012

The tree with bloody bark

Arbutus andrachne (Eastern strwaberry tree)
Tel Aviv University Botanic Garden. source: Eytan Chamovitz  
This evergreen is found in countries bordering the Eastern Mediterranean. It has a distinctive bark that peals off and renews each year, turning from greenish brown for the new bark to a bright red in mature bark. This blood-red color has spurned many legends and in Arabic and Hebrew, the tree is called "killed father". The tree's fruit is edible. Arbutus was mentioned by Virgil, Horace and Ovid.

Sunday, January 15, 2012

With Parsely and Sage and Thyme

Rosmarinus officinalis (Barlovento) 01
Rosemarinus officinalis (rosemary)
The rosemary shrub get its name due to its hardy nature. Rosemarinus means "dew of the sea" and rosemary plants can often grow with no water other than the humidity in the sea breeze. In addition to its culinary uses, rosemary may have pharmaceutical potential. A recent study showed that rosemary can influence both mood and cognition in people!

Thursday, January 12, 2012

Furry Females

Acalypha hispida (Chenille plant) 
Tel Aviv University Botanic Garden photo: Eytan Chamovitz
The Chenille plant is native to Oceania, but has been cultivated around the world due to its beautiful furry flowers. The plant is dioecious, meaning that there are distinct male and female plants, and of course only the females have the distinctive flowers.

Tuesday, January 10, 2012

What does the Venus flytrap feel?

How does a Venus fly trap know when to spring the trap? If you look at this video, you'll see that the trap only closes when the prey has meandered towards the middle of the trap. The plant knows that its prey has (1) reached the middle, and (2) is big enough to eat because it feels the insect. The large black hairs on the lobes of the trap are mechno-sensitive triggers that tell the plant that they've been touched, much like the hairs on your arm let you know when a fly has landed. To close, at least two of the trap's hairs have to be touched within about 20 seconds. A small bug can't touch two hairs that quickly, but a large one can. Once the bug (or small animal) touches two hairs, an electric signal, very similar to signals in our own nerves, initiates the trap closing.

Chapter 3 of WHAT A PLANT KNOWS is entitled "What a Plant Feels", and provides many more details on how the Venus flytrap and other plants feel their environment.

Sunday, January 8, 2012

Umkokola - A smelly apple

Dovyalis caffra00
Dovyalis caffra (Umkokola)
The Kei apple, or Umkokola, is native to southern and eastern Africa. This small tree yields an edible fruit, about the size of a crab apple. The little-known fruit is a traditional food in Africa and could be used to promote local food security issues. Umkokola fruits contain more vitamin C than an orange! But the fruit is rather smelly which has hindered its adoption as a crop.

Thursday, January 5, 2012

No yams, no Pill

Dioscorea mexicana (Mexican yam).
photo by Nhu Nguyen
Mexican yams were the original source of the chemicals that were used in the first oral contraceptives (affectionately known as The Pill) in the mid-20th century. These inedible wild yams (not to be confused with sweet potatoes, which belong to a different family of plants, but are are sometimes mistakenly referred to as "yams")  contain a chemical called diosgenin, a type of phytoestrogen. Scientists at the Mexican pharmaceutical company Syntex extracted Diosgenin from these yams and used it to make progesterone which in turn was used in the early versions of The Pill. In nature, Mexican yams are found in the rain forests of southern Mexico and Central American and are cultivated today primarily for the interesting "turtle shell" look of the tuber root.

Monday, January 2, 2012

Guest Blog: Paul Moore and the Mt. Atlas Pistachio

Paul Moore is a musician, traveling minstrel, founder of Ukuleles for Peace, and a lover of trees.

Pistacia atlantica
Paul Moore and a very old Pistacia atlantica (Mt. Atlas mastic)

Paul: I found this today while on a trip to look at stone for my house. This amazing Mount Atlas Pistache tree is next to Kibbutz Yiftah on the Northern Road of Israel. This could be the oldest one in the grove, or one like it, and is approximately 450yrs old. The most strange thing happened as I approached it: a Black cat jump out from the Center of the Tree... A witch's Tree no doubt! I am lucky to Live in a Forest in the Galilee Mountains in Mitzpa Harashim, We take our love of trees very seriously here! I hope to take pictures and tell more tree story's in the Future. The Galilee has an amazing amount of very old trees despite its size and the constant removal of trees over the centuries for fire, carpentry and more recently the railway. The Sacredness of some trees is still very much part of the inhabitants, be they Jew, Christian, Druze, or Muslim.

Danny: This species of pistachio is native from Iran to Turkey, through the Middle East to North Africa. It has many uses: The seeds can be eaten raw or turned into candy, the seeds also provide a useful oil, the plant contains a rubber that is used as a natural chewing gum, its sap is used to make incense and perfume, and the leaves contain chemicals used for tanning leather. The Mt. Atlas tree is dioecious, meaning that there are separate male and female trees.