"Ericaceae." A Dictionary of Plant Sciences. . Encyclopedia.com. (October 23, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/ericaceae
"Ericaceae." A Dictionary of Plant Sciences. . Retrieved October 23, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/ericaceae
Heath Family (Ericaceae)
Heath Family (Ericaceae)
The heath family, or Ericaceae, contains about 100-125 genera of vascular plants comprising 3,000-3,500 species. These plants are widespread in North
The most species-rich genus in the heath family are the rhododendrons (Rhododendron spp.), of which there are 850-1,200 species. The exact number is not known because species are still being discovered in remote habitats, and because the taxonomy of these plants is quite difficult and somewhat controversial among botanists. The “true” heaths (Erica spp.) are also diverse, containing 500-600 species. The blueberries and cranberries (Vaccinium spp.) include about 450 species, a few of which are cultivated for their fruits.
Plants in the heath family are woody shrubs, trees, or vines. Their leaves are simple, usually arranged in an alternate fashion along the stem, and often dark-green colored. The foliage of many species is sometimes referred to as “evergreen,” meaning it persists and remains functional in photosynthesis for several growing seasons. Other species have seasonally deciduous foliage. The flowers are radially symmetric, and are perfect, containing both staminate and pistillate organs. The fused petals (most commonly five in number) of many species give their flowers an urn- or bell-shaped appearance. The flowers may occur singly, or as inflorescences of numerous flowers arranged along the stem. The flowers of most species of heaths produce nectar and pleasant scents, and are pollinated by insects such as bees and flies. The fruits are most commonly a multi-seeded berry, a single-seeded drupe, or a capsule.
Species of heaths typically grow in acidic, nutrient-impoverished soils. Habitats range from closed to open forests, shrub-dominated communities, bogs, and tundras. All species of heaths have a heavy reliance on mycorrhizal fungi to aid in the acquisition of mineral nutrients, especially phosphorus.
Species in the heath family are prominent in some types of habitats in North America, particularly in forests, shrubby places, bogs, and alpine and arctic tundras. The most important of the North American heaths are described below.
The most diverse group is the blueberries and cranberries (Vaccinium spp.), the delicious fruits of which are often gathered and eaten fresh or used in baking and jams. Widespread species include the blueberry (V. angustifolium ), hairy blueberry (V. myrtil-loides ), tall blueberry (V. corymbosum ), farkelberry (Vaccinium arboreum ), deerberry (V. stamineum ), bog-bilberry (V. uliginosum ), (V. macrocarpon ), and small cranberry or lingonberry (V. oxycoccos ). Huckleberries also produce edible, blueberry-like fruits, including the black huckleberry (Gaylussacia baccata ), dangleberry (G. frondosa ), and dwarf huckleberry (G. dumosa ).
Various species of rhododendrons occur in North America, especially in moist or wet forests, heathy shrublands, and bogs in the eastern part of the continent. The white laurel or rose bay (Rhododendron maximum ) grows as tall as 32.8 ft (10 m), and has beautiful, large-sized, white or rose-colored flowers. The red laurel or rose bay (R. catawbiense ) grows to 19.7 ft (6 m), and has beautiful, lilac or purple flowers. Shorter species include the pinksterflower (R. nudiflorum ), mountain-azalea (R. roseum ), swamp-azalea (R. viscosum ), flame-azalea (R. calendulaceum ), and rhodora (R. canadense ). The California mountain laurel (R. californicum ) is native to coastal forests of the western United States.
Various species of the heath family are commonly known as “wintergreens,” because their foliage stays green through the winter, becoming photosynthetic again in the following spring. The shinleafs or winter-greens include Pyrola americana and P. elliptica, and occur in forests. One-flowered wintergreen (Moneses uniflora) occurs in damp forests and bogs. The spotted wintergreen (Chimaphila maculata ) and pipsissewa or prince’s pine (C. umbellata ) occur in dry woods, especially on sandy soils. The common wintergreen (Gaultheria procumbens ) is a common, creeping species of the ground vegetation of coniferous and mixed-wood forests of eastern North America, while shallon (G. shallon ) is a shrub of Pacific forests.
The May-flower or trailing arbutus (Epigaea repens ) is a low-growing, attractive, fragrant wild-flower, and one of the first species to bloom in the springtime. The bear-berry (Arctostaphylos uva-ursi ) is a low-growing, evergreen shrub, especially common in open, sandy woods.
Labrador-tea (Ledum groenlandicum ) is a shrub that grows in northern forests, tundras, and bogs of North America and Eurasia. Laurels are shrubs with attractive flowers, including the mountain-laurel (Kalmia latifolia ) and sheep-laurel (K. angustifolia ). The madrone or arbutus (Arbutus menziesii ) is a beautifully red-barked tree of the Pacific coast.
The Indian pipe (Monotropa uniflora ) and pinesap (M. hypopithys ) occur widely in rich woods in North America, and also in Eurasia. These species lack chlorophyll, and their tissues are a waxy, whitish yellow or sometimes pinkish in color, and the plants are incapable of feeding themselves through photosynthesis. Instead, they are parasitic on their mycorrhizal fungus, which provides these plants with organic nutrients through the saprophytic food web, which derives its flow of fixed energy from the decay of organic litter and detritus. Other chlorophyll-lacking, parasitic species include pine-drops (Pterospora andromeda ) and sweet pinesap (Monotropsis odorata ).
Several Eurasian species have been introduced as horticultural plants and have established wild, self-maintaining populations, although none of these has become extensively invasive in North America. These include the purple-flowered Scotch heather (Calluna vulgaris ) and several species of true heath, including Erica tetralix.
Some species in the heath family are cultivated as ornamentals in horticulture. The most commonly grown genera are the madrone or arbutus (Arbutus spp., including A. menziesii of North America ), heather (Calluna spp.), heath (Erica spp.), and rhododendron (Rhododendron spp.). Cultivated rhododendrons include the white laurel or rose bay (Rhododendron maximum ) and red laurel (R. catawbiense ), native to eastern North America, and California mountain laurel (R. californi-cum ), as well as the Asian azalea (R. indicum ) and garden azalea (R. sinense ).
The fruits of most species of blueberries and cranberries (Vaccinium spp.) are important crops in some areas, as are huckleberries (especially Gaylussacia bac-cata of eastern North America ). Any of these may be gathered from the wild, or they may be intensively cultivated in monocultures.
Various species of blueberries are cultivated in agriculture, including the so-called lowbush blueberries (Vaccinium angustifolium, V. canadense, V. penn-sylvanicum, and V. vacillans ), and the taller, high-bush blueberries (V. atrococcum and V. corymbosum ). These are typically grown on acidic, nutrient-poor, sandy soils, and the fields are burned every several years in order to stimulate the sprouting of new twigs and branches, which then flower profusely. Blueberry fields may also be fertilized, but only at a relatively small rate. This is because agricultural weeds usually respond more vigorously to nutrient addition than do blueberries, so that excessive fertilization can cause problems. When they are ripe, the fruits are usually picked with a hand-held implement called a rake, which is a scoop-like device with numerous prongs on its underside, which can harvest the blueberries without collecting excessive quantities of leaves.
Cranberries are also cultivated, usually on sandy, wet, acidic soils. The most commonly grown species is Vaccinium macrocarpon. During the autumn harvest, cranberry fields are often flooded, and when the berries float to the surface, the fields provide a spectacularly red vista. Cranberries are also harvested using a rake-like device.
The mountain cranberry or cowberry (Vaccinium vitis-idaea ) is collected in the wild, and is used in Scandinavia to make jams and a distinctive wine and liquor. All other cranberries and blueberries may be used to make jams, pies, and other cooked foods.
The common wintergreen or checkerberry (Gaultheria procumbens ) is a natural source of oil-of-wintergreen (or methyl salicylate), which can be distilled from the leaves of this plant, and also from the twigs and inner bark of some species of birches (especially Betula lenta of eastern North America). Oil-of-wintergreen is commonly used as a flavoring for gums, candies, and condiments. This substance is also sometimes applied by massage as an analgesic for sore muscles. Oil-of-wintergreen is apparently pleasantly sweet to drink, which is unfortunate, because this material is
Mycorrhiza —A “fungus root” or mycorrhiza (plural: mycorrhizae) is a fungus living in a mutually beneficial symbiosis (or mutualism) with the roots of a vascular plant.
Perfect —In the botanical sense, this refers to flowers that are bisexual, containing both male and female reproductive parts.
highly toxic if ingested in large quantities, so that children have been killed by drinking this medicinal product. The smaller doses obtained from drinking a pleasant-tasting tea, made by boiling a small quantity of leaves, is said to relieve certain pains and discomforts of rheumatism.
A relatively minor use of a member of the heath family is that of briar wood (Erica arborea ) of Europe, the wood of which has been used to make pipes for smoking tobacco.
See also Mycorrhiza.
Judd, Walter S., Christopher Campbell, Elizabeth A. Kellogg, Michael J. Donoghue, and Peter Stevens. Plant Systematics: A Phylogenetic Approach. 2nd ed. with CD-ROM. Suderland, MD: Sinauer, 2002.
"Heath Family (Ericaceae)." The Gale Encyclopedia of Science. . Encyclopedia.com. (October 23, 2017). http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/heath-family-ericaceae
"Heath Family (Ericaceae)." The Gale Encyclopedia of Science. . Retrieved October 23, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/heath-family-ericaceae