Sonoma Horticultural Nursery
FacebookTwitterPinterestLinkedIn

Q and A on Terminology

What is a rhododendron? Technically defined: A large genus of the ericaceae family (other members include: heath, heather, blueberry, cranberry, madrone) with a diverse range in flower, foliage, and form - from small, creeping shrubs 6” high to large trees 60’ or more. Most are evergreen but there are many deciduous types. On an informal level, they are usually thought of as large-leafed, medium to large growing, evergreen shrubs with large trusses (rounded clusters) of flowers, blooming in spring.

What is an azalea? A member of the rhododendron genus, but further sub-classified (by means technical and minute) into the sub-genera of Pentanthera and Tsustusti. Botanical nomenclature aside, they are considered small to medium-growing, evergreen shrubs with smaller leaves and flowers than “rhododendrons”. See Azaleas by group for more information.

What is a deciduous azalea? Generally, a more open-growing plant that loses its leaves in autumn, and usually more sun tolerant. Many have fragrance and/or bright fall color. Flowers range from narrowly tubular to funnel-shaped. There are many different types, both species and hybrids, and all are listed here as rhododendrons. See the cross-reference list for help finding an individual cultivar or species.

What is an azaleodendron? An informal name given to a cross of a large-leafed rhododendron with an azalea (deciduous or evergreen), resulting in a plant with characteristics of both parents. We list these with both the rhododendrons and azaleas. See the cross-reference list for more information.

What is a hybrid? A cross between two or more species, forms, or varieties, resulting in an unique form which is propagated asexually; from cuttings, grafts, or tissue culture.

What is a species? A group of plants that differs from its closest neighbors in both geographical and ecological distribution, and interbreeds true - i.e: the resulting offspring are the same.