Monday, July 9, 2012

The phytolace sewn by Queen Anne

Species name: Daucus carota

Common name: Queen Anne's lace, wild carrot

Location: Ontario

Queen Anne's lace is native to Europe and parts of northern Asia, although it is now considered naturalized in North America and an integral part of a prairie landscape. This doesn't, however, mean that it can't be invasive still; there are certain instances where it is a better competitor than native species and so the USDA has listed it as a noxious weed. The common name of this plant, Queen Anne's lace, is derived from the look of the flower: it is a type of inflorescence called a compound umbel, and at most stages of its development it looks like lace. The purpleish-red flower at the very centre of the inflorescence acts as a pollinator attractant, but is also said to be the drop of blood from where Queen Anne pricked her finger while making the lace.

The wild carrot has been domesticated into a subspecies of plant that we now use as the cultivated carrot. The genes that produce beta-carotene have been selected for over-production, so the cultivated carrot is orange compared to its white wild relative. The carrot is a biennial plant, which means it completes its life cycle over two growing seasons (in Canada, this would be two years since we have winter). The leaves appear the first year, photosynthesizing and making sugars to be stored in the taproot, the carrot, as starch. The plant then uses this stored starch to create a new shoot the next year which produces a flower and then seeds.

In agriculture, there are certain circumstances where this plant is actually a beneficial weed. The flowers attract wasp pollinators, which can benefit other plants surrounding it. When Queen Anne's lace is planted in tomato fields, the tomato yield increases over fields that don't have it. Not a bad idea for increasing yield chemical-free! There are some dangers to this plant, however. It has a wild relative that is also a look-alike called poison hemlock which can cause death to humans with consumption of only 6 or 7 leaves. The most famous victim of this poisoning is, of course, Socrates. Even without the poisonous plant confusion, wild carrot on its own can be harmful. The leaves contain chemicals which can cause severe light sensitive areas (burning, blistering, and extreme itching upon contact with sunlight) on the skin if you're especially sensitive to the chemical; if you're not as sensitive then it will just cause an itchy rash.

Medicinally, this plant was popular in the time of Hippocrates 2,000 years ago. He reported that this plant should be used as a contraceptive, and it was used for such a purpose for hundreds of years. The seeds were crushed, and the powdery substance was consumed. It was shown relatively recently that there are chemicals in the seeds of this species that do disrupt egg implantation, so I'm sure it would have been at least partially effective in the time of Hippocrates (and now). There is also some evidence to show it disrupts progesterone synthesis, which could also explain its potential effectiveness as a contraceptive. Very little mention is made of exactly how many seeds one would have to consume to get any noticeable effect.