North Coast Chapter - CNPS

The Heath Family

By Clare Tipple Golec

The Heath Family (Ericaceae) is a very cosmopolitan family of great beauty and delectability. Ericaceous plants are found everywhere with the near exception of Australia, where it is largely replaced by a related family Epacridaceae. The Pacific coastal region is characterized by an abundance and variety of ericaceous shrubs which often dominate the understory of mature coniferous forests as well as high elevations and peatlands, there are also large concentrations in the Himalayas, New Guinea and southern Africa. The Heath Family consists of a 100 genera and 3,000 species, and includes plants such as; rhododenron, azalea, manzanita, madrone, heather, heath, huckleberry, lingonberry, blueberry, cranberry, wintergreen, and many of the curious saprophytes (plants living off of decaying plant matter). The primary branches of this family (subfamilies) are; Rhododendroideae, Ericoideae, Wittsteinioideae, Monotropoideae, Pyroloideae, Vaccinioideae. The overall classification of the family and its allies has been a matter of dispute with last three subfamilies treated as separate families; Monotropoideae (lack chlorophyll), Pyroloideae (herbaceous habit), and Vaccinioideae (many have inferior ovaries).

Rhododendroideae has 19 genera and in the Pacific Northwest is represented by; Rhododendron (rhododendron and azalea, Greek for “rose tree”), Andromeda (bog rosemary, from Greek mythology Andromeda was the beautiful daughter of Cepheus and Cassiopeia who was chained to a rock in the midst of the ocean which bathed her feet until rescued by Perseus, indicative of the habitat mossy hummocks in swamps), Kalmia (swamp laurel, named after a student of Linnaeus who traveled extensively through northeastern America in the mid 1700’s), and Ledum (Labrador tea, Greek for a plant “Cistus ledum” with similar foliage).

Ericoideae has 20 genera, characterized by Erica (heath, Latin for “ling or broom”) and Calluna (heather or ling, Greek for “to look becomingly”). A subfamily not well represented in the Pacific Northwest, the only wild heath in California (Erica lusitanica) was introduced from southwest Europe and is quite invasive. A dominated shrub in many open and disturbed areas in the Trinidad area, these hardy European heaths aptly have been credited with a “high weed-smothering potential”.

Vaccinioideae has 50 genera, many of which are found in the Andes of South America. Some regionally common genera are; Arbutus (Pacific madrone with sinewy, graceful and smooth reddish limbs, Latin for “A. unedo, the strawberry tree” a common horticultural tree native to southern Europe and Ireland), Arctostaphylos (manzanita, Greek for “bearberry”, the berries are often a staple of bears with 60 species nearly all from the west coast of North America), Gaultheria (wintergreens, such as salal named after a botanist/physician of Quebec in the 1700’s), Cassiope (moss heather a dwarf creeping heather-like shrub, from Greek mythology Cassiopeia mother of Andromeda and wife of Cepheus King of the Ethiopians), and Vaccinium (an ancient Latin name applied to some berried shrub grazed by cattle, hence the Latin vacca meaning cow with many species such as blueberries, huckleberries, lingonberry and cranberries all with delightful eatable berries). Cranberry has been placed in it’s own genus Oxycoccos (Greek for “bitter-berried”), but currently the old generic name now reflects the species name (Vaccinium oxycoccos), the pollen of this species has been identified in ancient bogs millions of years old.

Wittsteiniodeae has one genus, Wittsteinia, from Australia, which has been place in the related family, Epacridaceae. Pyroloideae has 4 herbaceous genera; Pyrola (wintergreen, Latin for “little pear” in reference to the similar leaf shape), Chimaphila (Pipsissewa, Greek for “winter-loving” due to the evergreen habit), Moneses (Greek for “single delight” describing the attractive solitary and pendant flower), and Orthilia (Greek for “straight spiral” from one-sided inflorescence, a circumpolar genus of one to two species only). The leaves of many species of these genera have been used in the healing of wounds.

In Monotropoideae a variable number of species is recognized, some being; Allotropa (candy-stick, Greek for “other turn”, as the young flowers point up and the older ones turn downward), Hemitomes (gnome plant, Greek for “half sterile” because of the characteristic sterility of one of the paired anther-cells of each stamen), Hypopitys (pine-sap, Greek for “beneath a pine tree” in reference to the plant’s common habitat), Monotropa (Indian-pipe, Greek for “one direction” as the single terminal flower points downward), and Pterospora (pine-drops, Greek for “wing seed” due to the unusual seed with a large and translucent net-like wing at one end).

Two largest genera of the Heath Family, Rhododendron (1,200 species) and Erica (500 species), have remarkable concentrations of species in relatively small areas. The genus Rhododendron has 700 species in an area where the great rivers of eastern Asia break through the Himalayan chain and another centered in New Guinea with 300 species. The genus Erica has 450 species within Cape Province in southern Africa. The genus Gaultheria has a puzzling distribution that rings the Pacific Ocean.

Several genera of this family are poisonous and contain the same toxic compounds; mountain laurel (Kalmia latifolia, a plant of moist meadows, rock crevices, and bogs in the Sierra Nevada, Cascade Ranges and Klamath Ranges), Labrador tea (Ledum glandulosum, a plant of swampy areas along the north coast, and in the Sierra Nevada, Cascade Ranges and Klamath Ranges), Sierra laurel (Leucothoe davisae a plant of boggy areas in the Sierra Nevada, and Klamath Ranges), mock azalea (Menziesia ferruginea, found in the redwood forests of Del Norte and Humboldt Counties), Japanese pieris (Peiris japanica, a very common ornamental in California), rhododendrons, and western azalea. The toxic compounds are called andromedotoxins which produce cardiovascular disturbances in both animals and people, there have been fatal poisonings from children and livestock eating or chewing the leaves . These andromedotoxins are present in the entire plant including the nectar and honey, although bees normally do not work these flowers. The leaves of Labrador tea (“trapper’s tea”) were used by the native Americans and pioneers as a beverage tea, possibly low concentrations of this “brew” may have produced restorative effects (others report a relaxing effect) similar to those resulting from the caffeine in tea without a toxic effect. The yellow rhododendron (Rhododendron chrysanthum) leaves were widely used in Siberia as a remedy for rheumatism. The oil of wintergreen was another remedy for rheumatism (Gaultheria procumbens, a northeastern wintergreen of North America and close relative to salal). It is very important to bear in mind that difference between a plant being medicinal or poisonous may only be a factor of dosage or the part of plant used.

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California Native Plant Society - North Coast Chapter
P.O. Box 1067 Arcata, CA 95518-1067
Last updated August 1997