Rhododendron is a very large genus of about 1,024 species of woody plants in the heath family (Ericaceae). They can be either evergreen or deciduous. Most species are native to eastern Asia and the Himalayan region, but smaller numbers occur elsewhere in Asia, and in North America, Europe and Australia.
A hardiness zone is a geographic area defined as having a certain average annual minimum temperature, a factor relevant to the survival of many plants. In some systems other statistics are included in the calculations. The original and most widely used system, developed by the United States Department of Agriculture (USDA) as a rough guide for landscaping and gardening, defines 13 zones by long-term average annual extreme minimum temperatures. It has been adapted by and to other countries in various forms. A plant may be described as "hardy to zone 10": this means that the plant can withstand a minimum temperature of 30 to 40 °F.
Rhododendron groenlandicum is a flowering shrub with white flowers and evergreen leaves that is used to make a herbal tea.
Rhododendron macrophyllum, the Pacific rhododendron, California rosebay, California rhododendron, coast rhododendron or big leaf rhododendron, is a large-leaved species of Rhododendron native to the Pacific Coast of North America. It is the state flower of Washington.
About 1,702 species of plants live on the Arctic tundra, including flowering plants, short shrubs, herbs, grasses, and mosses. These plants are adapted to short, cold growing seasons. They have the ability to withstand extremely cold temperatures in the winter, and grow and reproduce in summer conditions that are quite limiting.
Prostanthera cuneata, commonly known as alpine mint bush, is a species of flowering plant in the mint family Lamiaceae, and is endemic to mountainous areas of south-eastern continental Australia. It is an erect, compact shrub with egg-shaped leaves with the narrower end towards the base, and pale lavendar to almost white flowers with purple blotches.
Rhododendron simsii (杜鵑) is a rhododendron species native to East Asia, where it grows at altitudes of 500–2,700 m (1,600–8,900 ft).
Rhododendron cinnabarinum (朱砂杜鹃) is a rhododendron species native to eastern Nepal, Bhutan, Sikkim, southeastern Tibet, and southwest China, where it grows at altitudes of 1,900–4,000 m (6,200–13,100 ft). It is a straggling evergreen shrub that grows to 1–3 m (3.3–9.8 ft) in height, with leathery leaves that are broadly elliptic, oblong-elliptic to oblong-lanceolate or ovate, 3–6 by 1.5–2.5 cm in size. The flowers are yellow to cinnabar red, sometimes ranging to plum colors.
Rhododendron fortunei is a rhododendron species native to China, where it grows at altitudes of 600–2,000 meters (2,000–6,600 ft).
Rhododendron lapponicum, the Lapland rosebay, is a dwarf rhododendron species found in subarctic regions of North America, Europe and Asia, where it grows at altitudes ranging from sea level to 1,900 m (6,200 ft). It is an evergreen prostrate shrub growing to 20–45 cm (7.9–17.7 in) in height, with leaves that are oblong-elliptic or ovate-elliptic to oblong-obovate, 0.4–1.5 by 0.2–0.5 cm in size. The flowers are reddish or purple.
Rhododendron molle (羊踯躅) is a rhododendron species native to China and Japan, where it grows at altitudes of sea level to 2500 meters. This deciduous shrub grows to 50–200 cm (20–79 in) in height, with leaves that are oblong to oblong-lanceolate, 5–11 by 1.5–3.5 cm in size. The flowers are yellow with dark red flecks.
Rhododendron nakaharae (那克哈杜鹃) is a rhododendron species native to northern Taiwan, where it grows at altitudes of 700–1,000 m (2,300–3,300 ft). It is a creeping evergreen prostrate shrub growing to 60 cm (24 in) in height, with leaves that are ovate to oblong or oblanceolate to broad-elliptic, 0.6–1.2 by 0.5–1.2 cm in size. The flowers are red.
Rhododendron niveum is a rhododendron species native to northeastern India, Bhutan, and southern Tibet in China, where it grows at altitudes of 2,600–3,500 m (8,500–11,500 ft). It is an evergreen shrub or small tree that grows to 2–6 m (6.6–19.7 ft) in height, with leathery leaves that are oblanceolate to elliptic, 8.5–11 by 3.6–4.6 cm in size. When young the leaves are covered in a white indumentum, which falls off the upper surface but remains on the underside. The flowers are an intense magenta or lilac, and held in a compact ball above the leaves.
Rhododendron keiskei is a species of flowering plant in the heath family Ericaceae, native to Honshu, Kyushu and Shikoku in Japan.
Rhododendron javanicum is a rhododendron species native to Indonesia, Malaysia, and the Philippines. This evergreen shrub grows to 5 m (16 ft) with bright orange flowers in spring. Plants may be terrestrial or epiphytic. Some forms from the Philippines may have red or bicoloured flowers, but are less often seen in cultivation.
Rubus tricolor is an evergreen prostrate shrub, native to southwestern China. Leaves are dark green above, pale green below, and stems have red bristles. It has white flowers in summer and edible red fruit. It grows approximately 0.3 m (0.98 ft) high and usually forming a vigorously spreading, dense mat. In cultivation, it is mainly used as groundcover. Common names include Chinese bramble, groundcover bramble, creeping bramble, Korean raspberry, Himalayan bramble, and groundcover raspberry. In Chinese, it is called 三色莓.
Rhododendron campylogynum (独龙杜鹃), the bent-style rhododendron, is a rhododendron species native to northeast India and northeast Myanmar, where it grows at altitudes of 3,500–4,500 m (11,500–14,800 ft). It is a small creeping or prostrate shrub that grows 0.5–3 cm (0.20–1.18 in) in height, with leathery leaves, obovate to obovate-lanceolate in shape, up to 2.5 cm by 1.5 cm but often much smaller. The leaves are glandular and are strongly scented of myrrh when crushed. The flowers are purplish red or pink colour and of a distinctive simple, somewhat nodding, bell shape, borne singly or in pairs on a short stalk.
Rhododendron campanulatum, the bell-flowered rhododendron or bell rhododendron, is a species of flowering plant in the family Ericaceae, native to the Himalayas and Tibet. An evergreen shrub to small tree, its leaves are ovate or broadly elliptic. Flowers bloom from April to May and are white to lavender in color. It is the state flower of Himachal Pradesh.
Ilex rugosa, the tsuru holly, is a species of flowering plant in the family Aquifoliaceae, native to southern Khabarovsk Krai, Sakhalin, and the Kuril Islands in Russia, and to eight mountain summits in Japan. It is usually quite prostrate and does well in areas with protective winter snow cover to prevent damage from late frosts.
Rhododendron ericoides is a species of rhododendron native to Borneo. It is found only on Mount Kinabalu. It is native to subalpine and alpine shrublands above 2,600 meters elevation.
