(Zhao Liangneng)
Scientific name: Rhododendron of Ericaceae. There are about 800 species of this genus, distributed in the north temperate zone. There are 650 species in China.
Function and use
Evergreen or deciduous. Life forms are diverse, ranging from shrubs a few centimeters high to trees 30 meters high, creeping sparsely or adhering to the bark of other trees. There are often hairs and scales on every part. Branches are usually clustered or sub-clustered. Simple leaves, alternate and usually clustered branches, mostly oblong or strip-shaped, entire; Pinnate vein; Petiole. Umbellies or racemes, usually terminal, bisexual, somewhat irregular; Calyx 5-lobed; Corolla wheel-shaped, bell-shaped, funnel-shaped or tubular, 5-lobed, often 2-lipped, gorgeous, with various colors and stripes, with a diameter of1~12cm; 5 ~ 25 stamens, anther apical pore dehiscence; Style sheet1; There is a disk; Ovary 5 ~ 20-loculed with many ovules. Capsule, septicidal. The seeds are small and numerous with narrow wings. China is produced in all provinces except Xinjiang. Strong adaptability, high mountains, low mountains, river banks, ridges, hanging rocks, as well as forests, shrubs, meadows, swamps and other habitats have suitable species. However, the mountainous areas with humid air, abundant rain and a lot of clouds are the most prosperous. Suitable for acidic humus soil, some varieties are drought-resistant and barren-resistant. This kind of tree is famous for its graceful posture and lush flowers. It is a treasure in the world garden and a wonderful flower in gardening and metallurgy. Tree wood is hard and fine, and can be used for farm tools, furniture and joinery. Leaves and flowers contain aromatic oil, which can extract essence. Some species can be used medicinally, such as Uncaria rhynchophylla, to treat bleeding, hemoptysis and irregular menstruation; Nephritis treated by Mao Dujuan; Petunia rubra Cure rabies; R.molle G.Don is used as an anesthetic.
Main types
There are many kinds of azaleas, and the common ones are as follows:
(1) R. arborum J. E. Smith: evergreen tree, 25 meters high. The leaves are oblong and lanceolate, with a length of10 ~ 20cm and a width of 3 ~ 6cm. The upper vein is slightly concave, and the lower vein is covered with white to rusty brown fur. Dense flowers, umbrella racemes, 20 flowers; Corolla tubular bell-shaped, 5-lobed, crimson, with 5 black glandular sacs at the base, all of which are dark spots. Capsule cylindrical, 3 cm long. China and Tibet. India, Bhutan and Sri Lanka are also distributed. Born at an altitude of1500 ~ 3000m. Can withstand the low temperature of -8℃. Introduced to Europe in the early19th century, it is famous for its gorgeous flowers.
② Pasteurella. Evergreen shrub, 3-5 meters high. Young branches are pilose and glandular hairy. The leaves are thin and thick, oval, 3 ~ 4 cm long and 1.5 ~ 2 cm wide, with no hair on both sides. Flowers are solitary in leaf axils of upper branches, clustered, with glandular hairs on sepals. Corolla white purple or reddish, wide funnel-shaped, about 3.5 cm in diameter, with red spots on the edge of upper lobe; Stamens 5, unequal in length; Ovary densely glandular setose. Capsule has glandular hairs. It is distributed in the south of the Yangtze River in China, south to South China and west to Sichuan and Guizhou. Sparse forests, shrubs and streams are common on hillsides.
③ Scutellaria barbata wall: evergreen trees, up to 20 meters. Branchlets and petioles have spiny bristles. The leaves are elliptic-lanceolate, 10 ~ 20cm long and 4 ~ 7cm wide. The lower surface is initially covered with loose wool felt and then becomes smooth. Flowers gather into umbrellas and cluster into balls; Corolla tubular bell-shaped, 5-lobed, crimson or blood red, with 5 black-red glandular sacs at the base. Capsule is 2.5 cm long and has bristles. China, southern Tibet. Sikkim and Nepal are also distributed. Born at an altitude of 3000 meters. Low temperature resistance-16℃. It is famous for its beautiful scenery in early spring in warm areas.
④ Rhododendron macrophyllum (R.basilicum Balf.f.et.W.W.Smith): evergreen tree, up to 10 meter. Branchlets have a reddish brown feeling when they are young. The leaves are thick leathery, obovate to oblanceolate in width, 13 ~ 32 cm long and 7 ~ 17 cm wide. The lower half is dark brown to light brown gray, covered with spongy fur, and the upper half is cup-shaped. The terminal umbel raceme has 20 flowers, dense; Corolla is bell-shaped, 8-lobed, pale yellow or crimson, with crimson patches at the base. The fruit is 4 cm long and densely covered with red and brown hairs. China endemic tree species, produced in Yunnan. Born in the rhododendron forest at an altitude of 3000 ~ 3300 meters.
⑤ Dryopteris crassifolia. : Evergreen trees, up to15m. Branchlets are stout and white when they are young. Leaves oblong-ovate to oblong-oblanceolate, or narrowly lanceolate, 20-30 cm long and 4-8 cm wide, with short white hairs at the bottom, and then smooth. Umbellies in racemes, with 15 ~ 20 flowers; Corolla bell-shaped, 5 ~ 7-lobed, white, reddish or lavender, with a black spot at the base; Stamens15 ~ 20; Ovary glabrous. The fruit is oblong and 2.5 cm long. China endemic tree species, produced in Sichuan and southwestern Shaanxi, were born in forests at an altitude of 2,000-3,000 meters.
⑥ Euonymus japonicus in Daour: semi-evergreen shrub, with a height of 1 ~ 2m. Branchlets are scaly and pilose. The leaves are nearly leathery, scattered, oval, long 1.5 ~ 3.5 cm, wide 1 ~ 1.5 cm, with blunt apex, short tip, scales on both sides and dense scales below; Petiole is 2 mm long. 1 ~ 2 flowers with lateral branches at the top and the first leaf open; Calyx scaly; Corolla funnel-shaped, about 1.8 cm long; Stamens 10, ovary densely scaly. Capsule oblong, 65438 0.2 cm long, with scales. Northeast China and Inner Mongolia. Japan, Korea and the Soviet Union are also distributed. Dry hillsides and forests.
⑦ R.delavayi Franch。 : Evergreen trees, up to12m. Branchlets are stout and white when they are young. The leaves are oblong-lanceolate to oblong-oblanceolate, 7 ~ 15cm long and 2 ~ 3cm wide, and the underside is covered with a thin gray-white to light brown sponge felt. 10 ~ 20 flower umbrella; Corolla bell-shaped, 5-lobed, crimson, with 5 glands at the base; Pedicels have reddish-brown hairs. Fruit length 1.8 cm. China, Yunnan, Guizhou. It is also distributed in Myanmar. Born in the bushes at an altitude of 2400 ~ 3000 meters.
⑧ R.fictolateum Balf.f: evergreen trees, up to15m. Branchlets are stout and have a slight brown feeling when they are young. The leaves are thick leathery, oblong-obovate to oblong-oblanceolate, with a length of 15 ~ 30cm and a width of 6 ~ 12cm. The lower part is covered with light yellow to rusty brown felt, and the upper part is funnel-shaped. Umbellies have 15 flowers, and pedicels have reddish-brown hairs; Corolla bell-shaped, 3 ~ 4 cm long, 6.5 cm in diameter, 7 ~ 8-lobed, white or reddish, with crimson patches at the base; The ovary is hairy. The capsule is 3 cm long. Endemic to China, it is produced in Yunnan and Sichuan, and is born in forests at an altitude of 3,000-3,900 meters. It is a national third-class key protected plant.
9. Rhododendron in Taiwan Province Province. ): evergreen trees, up to 10 m. Branchlets were initially covered with gray bran felt and soon became smooth. The leaves are lanceolate or oblanceolate, 8 ~ 16 cm long and 1.5 ~ 3 cm wide, and the lower part is covered with a light gray to light brown shell. Corolla wide funnel-shaped, 5-lobed, white or reddish, with purple-brown spots. China endemic tree species, Taiwan Province Province, was born in the broad-leaved forest at an altitude of 800 ~ 2000m.
Attending kumquat. Small evergreen tree, 5 meters high. The leaves are thick leathery, rectangular, 7 ~15cm long and 3.5 ~ 6cm wide. The underside is pale white, the sides are smooth and hairless, and the edges are slightly rolled down at ordinary times. The terminal umbel has 6 ~ 12 flowers, and the total peduncle and pedicel are glandular; Corolla bell-shaped, 4 ~ 5 cm long, pink, 7-lobed; Stamens14; Ovary 10 room has glands. Capsule oblong, 2 ~ 3 cm long. It is produced in the southeast of China, at the top of the mountain at an altitude of 1000 meters.
Grandwhite. : evergreen trees, about 10 m high. Branchlets are stout. The leaves are oblong-lanceolate to oblanceolate, or oblong-elliptic, with a length of 14 ~ 30 cm and a width of 8 ~ 13 cm. The underside is silvery white and covered with a thin adhesive layer. The petiole is 5 cm long. Umbellies have 20 ~ 25 flowers; Corolla bell-shaped, 8-lobed, gradually changing from light red to white, with purple glandular sac at the base; Ovary with nectaries and villi, 16 room. Capsule, 4.5 cm long. China, southern Tibet. Sikkim and Bhutan are also distributed.
Egyptian gourds. Evergreen shrub, 3 meters high. Young branches have fluff. The leaves are leathery, oval and oblong, 4 ~ 6 cm long and 2 ~ 3 meters wide, with a blunt tip and short tips, and rusty felt hairs below. The terminal umbel has 10 flowers; Pedicel 2 ~ 3 cm long, with fluff; Calyx is large, red, 5-parted and 5 ~ 10 mm long; Corolla tubular bell-shaped, crimson, fleshy, 5-lobed, 4.5 cm in diameter; Stamens 10, ovary densely hairy. There are alpine shrubs in China and western Yunnan. It is a national third-class key protected plant.
Chestnut tree : evergreen trees, up to 10 m. Branchlets have a sparse white feeling when they are young. The leaves are oval or obovate, 6 ~ 1 1 cm long and 2.5 ~ 4.5 cm wide, with tangled tufts only below the midvein. Umbrella racemes with 10 flowers; Corolla is bell-shaped, 5-lobed, white or reddish, with dark purple patches at the base. The capsule is 2 cm long. China endemic tree species, produced in Sichuan, Shaanxi, Hubei and Guizhou, were born in forests with an altitude of 2400 ~ 3000m.
Rhododendron in Yushan: evergreen tree, up to 10 meter. Branchlets stout, initially clustered, then smooth. The leaves are elliptic-lanceolate, 6 ~12cm long and 2 ~ 3cm wide, and the lower midvein is covered with tufts of hairs and glands. Corolla broadly bell-shaped, 5-lobed, white with purple spots. China endemic tree species, produced in the mountains in the middle of Taiwan Province Province, were born in forests at an altitude of 1650 ~ 3500m.
Rhododendron camptotheca Et wils: evergreen trees, up to12m. Branchlets stout, glabrous. Leaves oblong-lanceolate, 9 ~15cm long and 3 ~ 5cm wide, with sharp apex and no hair. Racemes with 9 ~ 12 flowers and glabrous pedicels; Corolla about 5 cm long, 5 ~ 6-lobed, white with lavender, with purple spots at the base; 20 ~ 25 stamens; Ovary glabrous, 14-loculed. This kind of fruit is 3 cm long. China endemic tree species, produced in western Sichuan, were born in forests at an altitude of 2300 ~ 2500m.
Rhododendron grandiflora var. giganteum (Forrest ex tagg) Chamberlain: evergreen tree with straight and stout trunk, which is 30 meters and 90 centimeters high in DBH, is the largest plant species in this genus. Branchlets are covered with thin gray-white felt when they are young. The leaves are oval or oblanceolate, with a length of 12 ~ 37 cm and a width of 4 ~ 12 cm, and the lower part is covered with a yellowish or yellowish brown coat; The petiole is 3 ~ 5.5 cm long. Terminal raceme, 25 flowers, 40 cm in diameter; Corolla funnel-bell-shaped, 8-lobed, crimson, with 8 glandular sacs at the base; Stamens 16, unequal in length; The ovary has villi. The fruit is 4 cm long and has rusty hairs. China endemic tree species, produced in western Yunnan, were born in sparse forests at an altitude of 2800 ~ 3000m. It is a national second-class key protected plant.
Rex dragon. Small evergreen tree, 7 meters high. When I was young, my branches were thick and fluffy. The leaves are leathery, 25 cm long and 8 cm wide, with blunt and round top, dark green top, easy to shed fluff at the bottom, and the upper layer of the indumentum is cup-shaped and hollow; The petiole is 4 cm long. Globular umbrella racemes with 20 ~ 30 flowers; Pedicel hairy, calyx teeth 8 ~ 9; Corolla bell-shaped, 5 cm long, rose red, with spots on the base of the inner surface and 8 lobes; Stamens16; The ovary is hairy. The capsule is 4 cm long and hairy. Endemic to China, it is found in northeast Yunnan and southwest Sichuan. It is a national third-class key protected plant.
Red berries. : evergreen trees, up to 10 m. Branchlets lavender, stout, about 2.5 cm in diameter. Rusty brown scales densely overlap under the leaves. Corolla funnelform, 5-lobed, purplish red with brown spots. China endemic tree species, Yunnan and Sichuan, were born in forests at an altitude of 2,300-3,300 meters.
Simsey Planck. : Also known as Rhododendron. Deciduous shrub, 1 ~ 2 meters high, clustered. Branchlets are thin and hairy. Leaves papery, oval or oval, short in spring; Summer leaves grow up, 3 ~ 5 cm long and 1.5 ~ 3 cm wide, with thick coarse hair below; Petiole is about 4 mm long. 2 ~ 5 flowers clustered at the top of branches; Calyx hairy; Corolla bright red, wide funnel-shaped, 4 ~ 5 cm long, 5 lobes, with crimson spots on the upper lobe; Stamens10; The ovary is densely hairy. Capsule ovoid, about 7 mm long, densely hairy. Produced in China, south of the Yangtze River, south to South China, west to Yunnan and east to Taiwan Province Province. Mountainous hills, elevation1200m.
Hericium erinaceus: a small evergreen tree, 4-5 meters high. The leaves are thick leathery, clustered at the top of branches, oblanceolate to oblong oblanceolate, 4-8 cm long and 2-2.5 cm wide, with a blunt top and a slightly downward-rolled edge, and a rusty yellow shell-like indumentum underneath. Terminal racemose umbel with 5 ~ 6 flowers; Calyx 5-lobed, glandular hairy; Corolla funnel-shaped bell-shaped, 3.5 ~ 4.5 cm long, pink with spots inside; Stamens10 ~12; The ovary is hairy. Capsule ovoid, 65438 0 cm long, covered with brown hair. China, South China to Nanling Mountains, elevation 1000 ~ 2000m.
Rhododendron camptotheca (R.sinogrande Balf.f.et W.W.Smith): evergreen tree, up to 1 1 m. Branchlets 1.5 ~ 2 cm thick, covered with fine gray hairs. The leaves are oblanceolate or oblong-elliptic, 90 cm long and 30 cm wide, with silvery gray or light brown skin-like indumentum below; The petiole is 5 cm long. The inflorescence is very large, with 20 flowers and a diameter of 20 cm; Pedicels have yellow hairs; Corolla bell-shaped, 8 ~ 10-lobed, milky white, with crimson patches at the base; Stamens ca. 20; The ovary is hairy. This kind of fruit is 3 cm long. China, Yunnan and Tibet. It is also distributed in Myanmar. Born in the rhododendron forest at an altitude of 3000 ~ 4200 meters. Introduced and cultivated in Europe. Low temperature resistance-12℃. It is famous for its huge leaves.
Sulfur bacteria. : evergreen shrub, 1 m high. The leaves are leathery, oval, 4 ~ 7 cm long and 2.5 ~ 3.5 cm wide, with blunt tips, green and white below, and small and dense scales on both sides. Calyx 5-parted, with scales outside; Corolla bright yellow, wide bell-shaped, 5-lobed, with orange spots on the lobes; Stamens10; Ovary has scales. Capsule ovoid, 65438 0 cm long. China endemic tree species, produced in Cangshan, Yunnan, was born in the Rocky Mountain at an altitude of about 3000 meters. It is a national third-class key protected plant.
Rhododendron semicircle: evergreen tree, up to 10 meter. Branchlets are green when they are young, with wax frost. The leaves are oval or nearly round in width, 4 ~ 8 cm long and 3 ~ 7 cm wide, with white to light green underneath. Corolla bell-shaped, 5-lobed, crimson, with black spots on the upper part of the back. China, southeast Tibet. Sikkim and Nepal are also distributed. Born at an altitude of 3300 ~ 3900 meters. Can withstand the low temperature of-14℃. It has high ornamental value and is also the parent of some excellent hybrid varieties.