Savage Garden: Diminutive Drosera and Attractive Anthocyanins

Oblong Leaf Sundew (Drosera intermedia)

Native to Europe, eastern North America, Cuba and northern South America, Oblong Leaf Sundew is a widespread drosera species. Considered a rosette drosera, this is one of a number of species that are extremely small, with whole plants sometimes measured in millimeters.

Spoon leaf Sundew (Drosera spatulata)

One of the most widely distributed sundews, the Spoon Leaf Sundew can be found throughout Australia, Tasmania, and across the Far East in China, Japan, Hong Kong, Taiwan, Borneo, and the Philippines. The leaves of this plant are highly variable, and many of the hybrids of the species can be found in striking colors.

This small species of drosera seeds readily and can grow like a weed in canrivorous plant collections. Flowers and seeds are produced on a tall stalk, high above the sticky leaves of the plant. As the seeds develop and the stalk dies, the stalk tips over and tosses it's load of seeds many inches away from the original plant. This plant is so successful and wide-spread, in part owing to the many types of soil where it can colonize.

Alice Sundew (Drosera aliciae)

Native to South Africa, the Alice Sundew is a popular drosera for cultivation. The leaves are tiny and often a deep reddish hue. In sunlight, this drosera produces an abundance of anthocyanin, a pigment which gives the leaves their bright color. This red pigment helps to attract insects to the sticky leaves of Sundews and into the waiting mouths of Venus Flytraps.

Anthocyanin Pigments

Anthocyanins are water soluble pigments that can provide can provide deep red, purple and blue coloration in fruit and plants, dependant upon pH levels present in soils and plants. Anthocyanin pigments makes pansies purple, blueberries blue and even autumn leaves turn red.

The bright colors provided by antocyanin pigments can serve several purposes:

• Pollination: Brilliant colors help to attract pollinators to flowers. Many pollinators, such as butterflies, have the capability to see in color. The colors provided by this pigment often prove very attractive to pollinators.
• Attraction: Fruits with bright and deep anthocyanin coloration, like blueberries and blackberries, attract animals by being obvious and easy to spot. This benefits the fruit plant when the fruit is consumed and the animal later deposits seeds in new places through their waste. 
• Sunscreen: The deep colors provided by anthocyanin pigments can help protect leaves by absorbing blue-green and ultraviolet light waves. This protects cells in the plant from high-light stress.
• Warning: The bright reds in some leaves and fruits may serve as a warning of unpalatability or may help to camouflage a plant by making it appear to be toxic. 
• Trapping: In the case of carnivorous plants, the red pigments created by anthocyanins attract insects and help to lure prey to the waiting, sticky leaves of the Sundews.

Anthocyanin pigments can also serve as pH indicators. In acids, anthocyanins appear red to pink. In neutral solutions, the pigment is purple. In the presence of alkalinity, the pigment becomes blue, green and then yellow as alkalinity increases. In high alkaline solutions, the pigment is entirely reduced and becomes colorless.

Anthocyanin dye from Red Cabbage shown with various pH levels, Image via Wikipedia.