Bristlecone Pine (Pinus aristata). White Mountains, California

Ginkgo leaves (Ginkgo biloba).

Coco de mer

Saffron. Harvested stigmas from saffron flowers (Crocus sativa), seen with their packaging. The bright red stigmas are part of the female reproductive structure of the flower (although Crocus sativa is sterile and must be propagated through corms). The stigmas are used to colour and flavour food. Saffron may also be taken as a herbal remedy to treat indigestion, rheumatism and colds. Historically, it was used to make dyes for paints and fabrics. Saffron is one of the most expensive herbs because of the time and labour involved in picking the flowers and separating the stigmas.

Bamboo tree stem and leaves. Photographed in Oaxaca, Mexico.

Frankincense. Lump of frankincense resin for use in traditional herbal medicine. This is the dried resin of the forest tree Boswellia frereana. Historically, this resin was used as a treatment for vomiting, dysentery and fevers. Now it is mainly used in the manufacture of incense.

Cinnamon sticks made from the dried bark of the cinnamon tree (Cinnamomum zeylanicum). Cinnamon is considered a spice and is used as a flavouring in cooking. Due to its distinctive fragrance it is also used in pot pourri and as an ingredient in toiletries and perfumes.

The towering trunk of a Californian Redwood tree Sequoia sempervirens, the base of which has been hollowed to allow cars to drive through. As an evergreen conifer it is the world's tallest species of tree (up to 100 metres/325 feet high). This specimen named the "Chandelier Tree" is 315 feet high, with a diameter of 21 feet, and an age of up to 2400 years. Sequoia sempervirens is not however, the largest, most massive of all living species. This attribute is given to the giant Redwood: a shorter species, but with a girth of up to 25 metres and age of 3000-4000 years. Sequoia are more likely to topple over before dying from old age. Photographed at Leggett in California, USA.

Phytoplankton bloom in the Bay of Biscay, satellite image Phytoplankton bloom in the Bay of Biscay, satellite image. North is at top. Water is blue, vegetation is green and cloud cover is white. Phytoplankton are photosynthetic microscopic algae. The bright green colour in the bloom (centre) is caused by chlorophyll and sediment.