Ericaceae

The Ericaceae are mostly shrubs, trees, or less commonly mycotrophic herbs comprising about 130 genera and 2,700 species. The leaves are simple and alternate or sometimes opposite or whorled; stipules are absent. The flowers are usually bisexual and actinomorphic or sometimes slightly zygomorphic. The perianth is in two whorls, a 4-7 merous calyx of usually connate sepals, and a 4-7 merous corolla of usually connate petals. The androecium has as many, or more commonly, twice as many stamens as corolla lobes or petals. The anthers typically dehisce by terminal pores and pollen is usually released in tetrads. The gynoecium consists of a single compound pistil of 2-10 carpels, usually a single style, and a superior or inferior ovary with 2-10 locules, each bearing 1-numerous, usually axile ovules. The fruit is usually a capsule or berry.

Each "thumbnail" image below is linked to a larger photograph.

	Arbutus menziesii, Pacific madrone. This cut away view reveals the internal arrangement typical of the urceolate flowers of the family. Insects probing into the open end of the corolla contact the appendages on the anthers and this causes the pollen to sift out of the terminal pores onto the body of the visitor. The pistil is clearly visible in the center of the sectioned flower.
	Arctostaphylos sp., manzanita.
	Cassiope tetragona, white or mountain heather.
	Erica sp., heather.
	Gaultheria shallon, salal, 1-3 - vic Newport, OR, 2002, 4 - vic Mt. Rainier, WA.
	Kalmiopsis "fragrans," fragrant kalmiopsis, vic. Umpqua, OR, May, 2004.
	Ledum groenlandicum, Labrador tea.  Wisconsin, June, 1969.
	Phyllodoce empetriformis, pink mountain heath.  1 - vic. Vancouver, BC, 2 - Mt. Rainer, WA.
	Rhododendron ferrugineum.
	Rhododendron indicum, azalea. This species has somewhat zygomorphic flowers. The terminal anther pores are barely visible in this photo.
	Rhododendron sp. The calyx in this genus is commonly very reduced. It is just visible as a yellowish rim at the base of the ovary of the immature fruit at the upper left in the first photo. The tubular base and spreading lobes of the corolla of the open flower are clearly visible, as are the 10 stamens, each with terminal pores releasing white pollen from the orange anthers. The greenish style with its enlarged stigma is also exserted from the corolla.
	Rhododendron sp., Corvallis, OR, 2002.
	Rhododendron sp., Lyon Arboretum, O'ahu.
	Rhododendron sp.
	Vaccinium calycinum, 'ohelo, 'ohelo kau la'au, blueberry, Hawai'i, endemic.
	Vaccinium corymbosum, blueberry, Corvallis, OR, July 2003.
	Vaccinium dentatum, 'ohelo, blueberry, endemic.
	Vaccinium ovalifolium, tall blue huckleberry, vic Mt. Hood, OR, 2002.
	Vaccinium reticulatum, 'ohelo. The inferior ovaries that are typical of this genus can be seen in this endemic Hawaiian species. The inverted urn-shaped or urceolate flowers illustrated here are common in several genera of the family.
	Styphelia tameiameiae, Epacridaceae, pukiawe, endemic.
	Chimaphila umbellata, wintergreen. This very close relative of the Ericaceae exhibits an identical floral construction. Note the five-parted corolla and the ten stamens, each with clearly visible terminal anther pores. The ovary is 5-lobed and 5-carpelled as is common in Ericaceae.
	Monotropa uniflora, indian pipe. This species lacks chlorophyll and is essentially devoid of any coloration. It forms an association with a fungus in order to survive.
	Pterospora andromedea, pine drops.
	Pyrola sp.  One of the mycotrophic species in the family with little or no chlorophyll.
	Sarcodes sanguinea. Note the lack of chlorophyll in this mycotrophic species.

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