Foxgloves

I found myself daydreaming about the foxglove, a lovely flower that is ubiquitous in the English landscape and appears from time to time in my garden. It's an easy plant to grow from seed, and can propagate itself from seed in the garden quite nicely. Looking back, I've grown three types, Digitalis purpurea (common foxglove), Digitalis grandiflora (perennial foxglove), and Digitalis mertonensis (strawberry foxglove). D. grandiflora is perennial and hardy, D. mertonensis is a short-lived perennial (a tetrapolid cross between D. grandiflora and D. purpurea) and D. purpurea is a biennial. Biennials grow foliage in the first year, and flower and set seed in the second year. The biennials die after setting seed. All should be planted in the ground in northern climates, as they will not survive the winter in a pot in zone 3 or colder.
Digitalis grandiflora in the rock garden:

Digitalis also one of those plants we are warned about as being poisonous, due to its content of chemicals that act on the heart. For the same reason, it is one of the most medically famous plants. The plant contains chemicals used in the heart drug digoxin (Lanoxin), a medication used for certain heart diseases (usually atrial fibrillation or heart failure), acting to slow and strengthen the heart beat. Overdose of the drug can result in cardiac arrest. As such, it is a drug (and plant) you must be careful with. I'd imagine the next 20 years of medical research will probably replace this drug with something a little less risky and easier to manage.

An antidote, called Digifab or Digibind, can be given intravenously to mop up toxic levels of digoxin and allow it to exit the body harmlessly via the kidneys. The product monograph is fascinating -- Digifab is made when sheep are injected with a digoxin-derivative attached to a chemical from the keyhole limpet (tiny crustacean that clings to rocks and boat hulls). The sheep serum extract is digested with a bit of pineapple enzyme and the important bits are separated out with a little chromatography, and voila!
Digitalis mertonensis in the raised bed:

Foxglove use was documented in medieval times, as an agent used by witches, when the plant was sometimes called witchs' bells. In the 18th century, a physician (William Withering) noticed that an old woman concocting herbs was having some success in treating edema (likely due to heart failure), and he is credited for discovering that among her collected weeds, digitalis was the effective tonic.
Some self-seeded Digitalis purpurea:

The medicine digoxin is extracted from Digitalis lanata, the wooly foxglove. Apparently, it is cheaper to extract the digoxin from the plant than it is to synthesize the chemical. Presumably, there are medicinal Digitalis farms in existence somewhere.

I have some Digitalis purpurea plants that will flower this year in my perennial beds, but in the interest of trying new and different plants, I would like to try some others. There is a good selection on this American mail order website, which I have ordered from before. I had no idea there were so many kinds! Digitalis are so easy to grow from seed, that I feel wasteful spending good money for them as plants at the nursery.

On the topic of other beautiful flowering plants - here are some pics from another blog, of National Primrose Society Show prize-winning flowers. Amazing.

Can Gardening Kill You?

A few months back, I posted about medicinal plants in my yard and neighbourhood. Then I thought about the particular hazards of gardening - reasons why we might need to put those medicinal agents to work! This combines two topics I know something about (gardening being the one I know less about) and is an intriguing assortment one doesn't often see in the gardening magazines:

(1) Tetanus - caused by the ubiquitous soil bacteria, Clostridium tetani. It is easily prevented by a tetanus shot every 10 years (are you up to date?). Can be caused by soil contamination of any cut. Slow death by tetanic spasm of all your muscles. Gruesome.

(2) Sporotrichosis - Death by a rose: are you a rose fancier with a chronic ulcer on your hand? Moss, barberry bushes, and roses are common sources of the fungus Sporothrix schenckii. Infection is more common in those with poor immune systems (chemotherapy, AIDS, diabetes). Here's a good reason to have thick leather gloves when working with roses!

(3) Skin Problems/Dermatitis - Irritant, Phototoxic, and Allergic:

e.g. Berloque (phototoxic) dermatitis - Mark of the lime: the oil of the bergamot lime has been used in perfumes and causes a skin response similar to an overactive sunburn, turning areas brown after sun-exposure. Perfumes are now required to be bergapten-free because of this problem. Photodermatitis can also be caused by contact with celery, parsley, parsnips, giant hogweed, or carrots plus sunshine.

e.g. Irritant and allergic dermatitis - Euphorbia (spurge) and primulas commonly come with a warning about skin irritation caused by touching the plant. "Tulip fingers" or "Garlic Fingertip Dermatitis" are caused by frequent exposure to these plants, just as florists can be sensitized to Alstromeria. Poison ivy, poison oak, poison sumac: most gardeners should know to avoid these!

(4) Allergic cross-reactions- Did you know that an allergy to ragweed can be associated with a reaction to chamomile tea? Asthmatics may be severely affected. Botanically, ragweed and chamomile are quite close (both in family Compositae). For that matter the cross-reaction can also apply to bananas and canteloupe.

(5) Insect bites and stings - They are annoying to the most of us and deadly for those with anaphylactic reactions to bees and wasps. Perhaps an Epi-Pen should be one of your gardening tools. We northerners can rejoice that the mosquito that carries West Nile Virus hasn't ventured this far north.

(6) Back injuries, tendonitis, sprains and strains...do you stretch before gardening? I don't, but maybe I should. Maybe I should also leave the hauling of large boulders to machines and stronger people.

(7) Hernias - Again, leave the heavy lifting to the appropriate people/machines.

(8) Parasitic infestation - I recall a case of some Vancouver city folk who decided to fertilize their garden with their own excreta and shared vegetables with the neighbours. The carrots tasted fine, but then the neigbours came to the ER with foot long Ascaris lumbricoides worms in a jar, wondering where they picked these up. Moral of the story: Don't poop in your garden and don't let the dog do it either. Frighteningly, 4 million Americans are believed to be infected, though most probably don't know it. Ascaris is indigenous to the rural southeastern US, where cross-infection by pigs infected with A. suum in believed to occur. Contact with cat feces can cause Toxoplasmosis, an infection hazardous to pregnant women and persons with AIDS.

(9) Problems related to ingestion of pesticides - diverse effects; a good reason to try cultural methods before resorting to chemicals.

(10) Legionnaire's disease - this severe lung infection is generally associated with contaminated air conditioners, but in 2000, there were the first documented reports of potting soil being the common source in a group of infections in the United States.

(11) Eating poisonous plants - hopefully, your plant identification skills will steer you away from the Digitalis (Foxglove), Aconitum, and Ricinus (Castor bean).

(12) Sunburn and skin cancer - Melanoma, basal cell carcinoma, and squamous cell carcinoma are all at least partially-related to sun-exposure. Hats, clothing, sunscreen, and sunglasses are great ideas. Besides, sun exposure ages skin prematurely and we all want to be beautiful old gardeners!

(13) Other animal bites - snakes, dogs, cats, bats (my dad was bitten by a rabid bat - was treated, lived to tell about it) etc.

(14) Bumps, scrapes, and slivers - we put up with alot for the sake of our gardens!

P.S. I see that the caring government of Canada has established a website on garden safety that covers a few things I've left out.

Wow! I can't believe I came up with 14 categories of garden hazards. Congratulations if you actually read that whole list. Now go out and garden...with caution.

Medicinal Plants

When we first moved here, I was quite interested in growing a pharmaceutical or physic garden, with medicinally important plants. I am also interested in ethnobotany of the indigenous populations (Woodland Cree). Unfortunately, many of the traditionally important plants are unknown among the local population I have talked to. Few seem to know the names of the medicinal plants anymore.

The most well-known medicinal plant in our area is called "ratroot", also called wild ginger or sweetflag. I believe the scientific name for this plant is Acorus calamus. I know it is a plant that grows in marshy areas (and munched by the muskrat) and the root is harvested and used to make teas or to be chewed directly. At the very least, there don't seem to be any significant toxicities related to it. Its actions are usually described as a general "cure for what ails you". Like any good medicinal agent, it tastes terrible! Some locals harvest it, and it can be purchased from the trading post. Here is a picture of some ratroot we keep around the house, for no particular reason:
Some medicinally or ethnically important plants in my yard:

Willow: tree that contains salicin, a natural "aspirin"; branches of willow can be used to construct sweatlodges, and thus the steam produced inside could contain salicin.

Digitalis (Foxglove): contains a cardiac glycoside, which slows the heart rate, which also explains how it can kill you.

Convallaria majalis (Lily of the Valley): contains cardiac glycosides

Mondarda didyma (Bergamot, Oswego Tea): the Oswego natives (eastern Canada/US) made tea from this citrusy-scented herb.

Yarrow and Saskatoonberry grow wild, and both were important to indigenous peoples.

Also, Thymus vulgaris (Thyme)Lavandula angustifolia (Lavender)Echinacea purpurea (Purple coneflower).

Other traditional medicines still used in the local northern communities are bear grease and spruce gum (usually rubbed into the skin for rashes, but more often the spruce gum will increase irritation in eczema or psoriasis). Though probably a more recent remedy, the use of lard for a variety of ailments is common. Some women believe that eating a large amount of it will bring on labour. If not childbirth, the vast amount of fat should at least bring on the pain of a gallbladder attack.

Unfortunately, there is little remaining knowledge of traditional medicines. This is probably due to the colonial institutions that suppressed traditional practices and tried to force western medicine on the local peoples. Of course, at the time of colonization, there were no great cures for tuberculosis, so native people knew schools and hospitals as places to aquire and die of lung disease. Due to various social issues, tuberculosis is still common among Canadian Aboriginal communities. A few years ago, I read an interesting book on the social and medical history of the local peoples:

Maureen K. Lux, "Medicine That Walks: Disease, Medicine, and Canadian Plains Native People, 1880-1940". University of Toronto Press, 2001.

From the back cover: "Biological invasion, Lux argues, was accompanied by military, cultural, and economic invasions, which combined with both the loss of the bison herds and forced settlement on reserves, led to population decline. The diseases killing the plains Aboriginal people were not contagious epidemics but the grinding diseases of poverty, malnutrition, and overcrowding."