Gathering the Laurels

I grew up enjoying the site of mountain-laurel blooming in profusion each June. It is a common understory shrub in the Hudson Highlands, one of the northeast-southwest-trending chains of mountains that make up the northern Appalachians through downstate New York. Kalmia latifolia is an evergreen member of the Ericaceae (heath family), but it is definitely most noticeable when it flowers. The pink-tinged white blossoms are arranged in corymbs; the petals are attached to form pentangular bowls. The corymbs are several inches across; each flower is about an three-quarters to an inch in diameter. It is a showy plant.

Mountain-laurel in flower in Maryland.
Mountain-laurel in flower in Maryland.

In addition to their large size, the flowers are set against glossy, dark green foliage. K. latifolia has the tendency to form large, continuous thickets, sometimes covering part of an acre on rocky, well drained hillsides. In the southern Appalachians, they can attain the size of a small tree (over 20 feet tall), but in the northeastern states they are usually five or six feet tall.

I haven’t seen any mountain-laurel on Martha’s Vineyard yet, but it does occur here and is likely to be found “up-island” in the towns of West Tisbury, Chilmark, and Aquinnah. The Gay Head and Martha’s Vineyard Moraines create a series of northeast-southwest-trending ridges that form the upland portion of the island. The terrain is dotted with large boulders (especially in the Gay Head Moraine areas) and was apparently originally forested with more beeches and maples (Northern Hardwood assemblage), tempering the dominant Oak-Heath presence that still dominates the down-island portion of the island, which a sandy outwash plain formed by the erosion of the moraine.

Sheep-laurel. (Photo: Bob Cunningham)
Sheep-laurel. (Photo: Bob Cunningham)

The most common member of the heath family in the outwash plain is the sheep-laurel, Kalmia angustifolia. This is a much smaller plant than K. latifolia, getting only about three feet all, but it has the same tendency to grow in extensive thickets. It is a common part of the Oak-Heath assemblage wherever it is found. It has evergreen leaves that hang down at a sharp angle. As its trivial name implies, the leaves of sheep laurel are narrow. It can also be distinguished from other Kalmia species because its branches end in terminal whorls of leaves, while the flowers emerge from the stem beneath the terminal leaves. The flowers resemble those of mountain laurel, but are a deep pink and much smaller.

The third member of the genus that is found in the northeastern U.S. is Kalmia polifolia, the bog-laurel. While the other two species are associated with mesic or even dry habitats, K. polifolia lives up to its name and is strongly associated with hydric conditions, although not necessarily bogs. K. polifolia is distinguished from K. angustifolia by the position of its flowers, which are terminal rather than growing further down the stem like the sheep-laurel’s. K. polifolia also blooms in the spring (April or May) rather than in the early summer.

Bog-laurel
Bog-laurel

All Kalmia prefer acidic soil conditions. But while sheep-laurel grows on a variety of sites ranging from wet sphagnum bogs to dry jack pine forests, bog-laurel is confined to wetlands (it is also called “swamp-laurel”). Mountain-laurel, on the other hand, prefers drier sites, but can tolerate moist soils at the edges of wetlands. While the sheep-laurel is widespread on Martha’s Vineyard, the bog-laurel is not found here at all.

The fourth member of the heath family found in the Northeast is Kalmia procumbens, the alpine-azalea, but as its name suggests, it is confined to the tundra-like areas on the higher peaks of New Hampshire and Maine and grows to be only 4 inches tall.

All parts of all members of the genus are poisonous to many mammals. The sheep-laurel gets its name for its morbid effect on that species, but the plant is poisonous to all livestock, as well as to humans. Some mammals, caribou for example, can tolerate it, and many birds depend on the fruits for winter forage.

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Yew Are Everywhere

Aril fruit of T. baccata

The yew is one of those ubiquitous foundation shrubs that far more people recognize than know its name. They are planted next to private homes and in public parks all over the Northern Hemisphere in part because they are relatively slow growing and but also because they are highly resistant to air pollution. They occasionally draw attention to themselves because they are poisonous to eat and children may have difficultly resisting the bright red berries (arils) on the female plants (the yews are dioecious). On the other hand, all yew species produce taxol, a chemical that has been used in cancer treatments.

My own fascination with yews might have started at age 10, when we moved into a 19th century Victorian house that had several large specimens growing in beds along the east side of the house. They had become greatly overgrown, crowding over the stairs that led into the house and with their branches pressed up against the shingles. In one bed two white cedars (Thuja) hung over the yews, leaning away from the house because they had been planted only about three feet from the foundation.

My mother, determined to bring some order to the landscape, organized a family project to cut down all of these conifers to stumps. At the age of 10 this struck me as pretty nearly criminal because this thicket of evergreen foliage and sturdy low-lying limbs seemed like a perfect hideout. I also had a somewhat reflexive idea that perfectly healthy trees shouldn’t be cut down and remember arguing for some less radical pruning.

Enormous yew hedge at Powis Castle

In the end only two of the yews and two of the cedars were cut back, and my mother, who literally owned a set of horticulture encylcopedias, assured me that the yews would grow back and that the cedars, like most conifers, would not sprout from stumps. I only half-believed her until the yews did actually begin growing back. For a while they looked like abstract sculptures erupting from the ground, but after three or four growing seasons they were shrubs again, now much more reasonably sized.

It may have been when I was in college that I learned that there was actually a yew native to the northeastern United States, and that I had never seen it because deer had browsed it into rarity. Taxus canadensis is found from Newfoundland and Labrador west to Manitoba and south in the mountains to Tennessee and Virginia. It is, however, listed as threatened or endangered in several states.

Over the years I have seen it only rarely in the woods, most recently far up Taughannock Gorge near Ithaca, where I have never seen a deer. The deer must, however, browse those yews because they are quite small. The area has been parkland for decades and yew can grow to be 20 feet tall if left undisturbed. The Taughannock specimens are spindly stalks perhaps two or three feet high.

There are large yews in the village park at the corner of McLallen and Old Main streets in Trumansburg. These are large specimens, approximately 15 feet tall, but they unlikely to be the native species. Most yews planted in designed landscapes are Japanese yews (T. cuspidata) or one of the many hybrids developed by crossing the Japanese species with one of the seven other species found in amazingly varying environments throughout the Northern Hemisphere. The Trumansburg park shrubs have been heavily browsed by deer, but they are actually too tall for the deer to reach the top third of the foliage. This gives them an unintentionally graceful appearance, their many anastomosing trunks nearly denuded of greenery resemble squat, coniferous versions of African acacias, the lower limbs of which are heavily browsed by antelope and giraffes.

In their native habitat yews are understory trees, which means they are adapted to doing well with relatively limited light. This also endears them to landscapers. The Trumansburg park yews seem impressively healthy growing beneath several towering sugar maples. The shallow root systems of maples often make it difficult to grow anything beneath them.

The bark of the Pacific yew, former source of taxol

Pacific yew (T. brevifolia) grows in the understory of the towering coniferous forests of the Northwest. It is less common than it once was in part because of logging operations; clear-cutting machinery tends to destroy the understory trees in the process of removing the canopy trees. But there is a large demand for yew bark because of its importance in cancer research and overharvesting is depleting the shrubs in some parts of its range. According to Gordon Cragg of the National Cancer Institute:

In 1988, the NCI acquired 27 700 kg (60,000 lb) of dried Pacific yew bark, collected from trees cut down in southwestern Oregon. On average, one yew tree yielded 18 kg (40 lb) of green bark, which weighed about 9 kg (19 lb) dried (7). From the 27 700 kg of dried bark, about 4 kg (9 lb) of dry, crystalline taxol was extracted. Clinicians in several locations across the country have asked for increased supplies of taxol to expand tests to a broader range of cancer types. In January 1989, the NCI solicited another 27 700 kg of yew bark.

Cragg acknowledged that the harvest of Pacific yew was not sustainable.

By 1993 Bristol Myers Squibb had developed a laboratory process to produce taxol from a cell line propogated in an aqueous medium and that effectively ended the threat to wild Pacific yew.

Diet of Flowers

Flowers are not just for looking at, or even just for smelling. You can eat them too. Culinary use of flowers experiences periodic revivals, but has been know since ancient times. The last surge in flower-as-ingredient was probably in the 1980s with the rise of nouvelle cuisine. At that time they were also used extensively as a garnish.

Japanese food

One of the more lampooned features of nouvelle cuisine during its initial phase was the enormous size of the plates and the relatively small portions. There were huge expanses of plates that positively cried out for decoration, at least to some. That period actually saw the bridging of two arts: flower arranging and cooking. The flowers were in the food and next to it too.

Before bringing flowers into the kitchen, though, some reading, even research is in order. There are many caveats to including flowers in cooking. One, flowers may include pollen (if they are male or “perfect” flowers) and many people are allergic to pollen. For example, ragweed is hay-fever-inducing whether it is eaten or inhaled.

If you consider yourself to be an allergy-prone person, then eating flowers may not be for you at all. A safe course for anyone may be to remove the anthers and other parts of the plant that may be heavily coated with pollen grains.

Two, some flowers are poisonous. These include some very attractive and very common flowers like those of rhododendrons, azaleas, daffodils, crocuses, foxglove, cardinal flower and clematis. There are lists of poisonous flowers all over the Web. In some cases – rose, tulip, yucca and lavender – only the petals are edible.

Jimsonweed

One writer, Ann Lovejoy of the Seattle Post-Intelligencer, was startled to look through cooking magazines and see very toxic flowers placed as ornamentation on various dishes. These included Datura stramonium (devil’s trumpet), which is wildly hallucinogenic and will stop your heart if a sufficient quantity is consumed. The active ingredient is strychnine.

Three, some flowers are poisonous because they have been sprayed with herbicides or pesticides. Do not eat flowers purchased at florists or collected along the roadside. The decay periods for chemicals sprayed onto crops are well studied. Those for chemicals sprayed onto plants not usually thought of as food are not, so it isn’t safe to eat this vegetation regardless of how long ago it was sprayed.

The safest course of action is to grow your own flowers to eat. Sherry Rindels at the Department of Horticulture at Iowa State University recommends picking only fully open flowers, not those either still partially closed or past their prime and wilting. Also, she commends picking them during a cooler part of the day.

“After harvest, place long-stemmed flowers in water and then in a cool location,” counsels Rindels. “Short stemmed flowers should be placed between layers of damp paper toweling or in a plastic bag in the refrigerator. Immediately before using, gently wash the flowers to remove dirt and check for insects.”

Harvesting flowers

People around the world have been eating flowers for centuries. One of the more detailed articles about the historical dimension of the topic is by Lynn Smythe at Associated Content. In short it is one of those things that the Chinese and the Romans both did, introducing the idea to various other cultures during imperialist expansions.

According to Smythe, flowers were a popular addition to salads during the Victorian Era, but they were also pickled so that they could be used during the months when no flowers were available for harvest.

There are a number of sites with lists of edible plants, but all of them suggest that you learn your plants really well before including them in your diet.

Some sites with lengthy lists of edible (and inedible) plants:

What’s Cooking America

About.com

Colorado State University Extension

National Sustainable Agriculture Information Service

The Garden Helper

And for recipes that use flowers: The Seeds of Knowledge