BEGONIA (Begoniaceae)

Begonia rex (fan plant) origin: Malaya.

Truly the king of begonias. The flowers are insignificant, but the fan-shaped leaves display a wide range of colour combinations in intricate and delicate patterns. The surface of the leaf is hairy to prevent excessive transpiration, and the edges are toothed. Although classified as a delicate plant, it will last for a time in the house if humidity can be provided. An arrangement on a peat base in a bowl, or in a slightly cool position, is ideal. Always keep the plant moist, but do not over-water in winter. A draught-free, light position is advisable, though not in direct sunlight. A minimum temperature of 55° F. (13° C.) is essential.

Leaves of Iron Cross Begonia

Leaves of Iron Cross Begonia (Photo credit: Wikipedia)

B. masoniana (Iron Cross begonia) origin: Malaya. A striking variety with bright green leaves similar in shape to those of B. rex, but smaller and more rounded.

They are covered with rounded nodules, giving a moss-covered effect. In the middle of the leaf there is a clearly defined purplish cross. This plant requires similar treatment and conditions to B. rex, but it is rather slow growing and will benefit from feeding during the growing period.

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03. February 2013 by admin
Categories: Houseplants, Plants | Tags: , | Comments Off on BEGONIA (Begoniaceae)

Begonia Begoniaceae

The genus Begonia includes more than 2,000 species and hybrids, and they are as varied in appearance and habit as these numbers suggest. Some are valued mainly for flowers, some for decorative leaves, some for both leaves and flowers. Begonias range in size from tiny, ground-hugging creepers to stout-stemmed specimens 8-10 feet tall. Yet they all share a number of characteristics. Almost all forms have asymmetrical leaves; the leaves always grow alternately along the stems; and new leaves emerge from stipules (leaflike sheaths). And many begonias do not require continuous direct sunlight, a fact that makes them particularly suitable for indoor use.

Most kinds bear flowers in clusters on short stalks arising from or near leaf axils. There are separate male and female flowers on the same plant, however, each cluster normally composed of either all male or all female blooms. Male flowers tend to be the more eye-catching, partly because their petals are often of different shapes and sizes, whereas the petals of a female flower are more nearly alike. A distinctive feature of the female flower is the seed-bearing ovary, which looks like a three-lobed appendage immediately behind the petals. Female flowers, although they may slightly fade, usually last for weeks or even months, but the male flowers tend to drop off within two or three days of opening.

Because the genus is so large, it is generally divided into groups based on the differing storage organs or root structures of these plants. Some have fibrous roots (as most plants do). A second group consists of species in which roots grow down from a thick creeping rhizome. A third group includes tuberous species that have a fleshy, swollen storage organ at the base of the stem. In these pages fibrous-rooted and rhizomatous begonias are discussed together because their growth cycles and cultivation needs are similar—and are very different from those of the tuberous kinds.

Fibrous-rooted and rhizomatous begonias

There are, roughly, three different kinds of fibrous-rooted begonia. Many species have smooth, rather woody stems marked here and there by swollen, knotted joints (nodes) a bit like the stems of bamboo. These plants usually have leaves like angel’s wings—lobed near the top and acutely asymmetrical. A second kind of fibrous-rooted begonia has fleshy stems, and many parts of the plant— especially leaves and flowers—are covered with hairs. These plants (commonly known as hirsute begonias) are usually bushy, like those with bamboo-like stems, although they will sometimes trail if left unsupported. So they are often grown in hanging baskets. Finally, there are the fleshy-stemmed wax begonias, whose crisp leaves are waxy, not hairy.

Most fibrous-rooted begonias flower profusely, and are grown both for their flowers and their decorative foliage. The flowers vary in size and colour, but most have only a single layer of petals.

The rhizomatous begonias often have a thick, fleshy rhizome, which crawls over the surface of the potting mixture, sending down roots at intervals. The plants of most species grow less than 9 inches tall. The few that grow taller often need supporting with thin stakes. Many of these plants are without conventional, erect stems, but a few have much-branching, fleshy stems. Rhizomatous begonias are prized for their foliage. Leaves may be nearly circular, roughly star-shaped, or heart-shaped. Some plants have miniature leaves, some huge, some in between. Flowers are always small, each with only a single layer of petals.

RECOMMENDED BEGONIAS: FIBROUS-ROOTED

B. ‘Alleryi,’ a hirsute begonia, grows 3-4 feet tall. Its pointed-oval, tooth-edged, hairy leaves are 6-9 inches long, 3-4 inches wide, and bronzy green with reddish purple veins on the underside. Rose-pink flowers 2 inch wide appear in summer and fall. B. coccinea (angehving begonia) has only a few bamboolike stems 3-4 feet tall. Leathery, obliquely oblong leaves are 4-6 inches long and 2-3 inches wide with slightly toothed, undulate edges. Leaf surfaces are grass green tinged at the edges with red above, and dull red below. The 2-inch-wide, waxy, coral red flowers appear in large, drooping clusters on red stalks from early summer to mid-fall.

B. compta has bamboolike stems. Some stems droop. Others grow erect up to 3-4 feet. Pointed-oval leaves, 3-6 inches long and 2-4 inches wide, are grey-green above marked with silvery white along the broad vein channels, and bright red below. The white, ½ inch-wide flowers are rarely produced indoors.

B. ‘Corallina de Lucerna’ (sometimes called B. ‘Lucerna’) is a vigourous, bushy plant that grows to 6 feet tall. The bamboolike stems are green at first but turn woody and brown. Lance-shaped, glossy leaves 4-8 inches long and 2-4 inches wide are green with white spots above and deep red below. The deep pink to bright red, ½-to ¾—inch-wide flowers appear in pendent clusters of about 50 throughout most of the year.

B. luxurians (palm-leaf begonia) has fleshy, slightly hairy, red stems 2—3 feet tall and hairy, palmlike, light green leaves divided into as many as 17 lance-shaped leaflets 3-6 inches long and 1 inch wide. The creamy white, ½ inch-wide, hairy flowers seldom appear indoors.

B. maculata has much-branching bamboolike stems 2-3 feet tall, that are green when young but turn woody and brown. The lance-shaped, slightly tooth-edged leaves are up to 6 inches long and 4 inches wide, with rounded lobes at the top. Leaf colour is dark green with silver markings above and crimson below. The ¼-inch-wide, mostly pale pink flowers are carried on drooping, reddish flower stalks. Blooms may appear in all seasons, but are most abundant in summer. An attractive variety, B. M. Wightii,’ has narrower, longer leaves with large silver spots and big white flowers.

B. metallica (metallic leaf begonia) is a hirsute begonia 3-4 feet tall. Its 6-inch-long and 4-inch-wide oval leaves are lobed, tooth-edged, and covered (as are the stems) with rough white hairs. Leaf colour is olive green with a metallic gloss, and the deep-set veins are purple. The whitish, ¼ inch-wide, summer-blooming flowers are covered with spiky pink hairs.

B. ‘Preussen,’ has much-branching bamboo-like stems that form a bush up to 18 inches tall. The pointed, heart-shaped leaves are I-2—2 inches long and wide, and bronze-green with some faint silver spotting. The continuously blooming pale pink flowers are about 2 inch across.

B. scharffii (often called B. haageana) is the most popular hairy-leaved begonia. Fleshy, upright stems 2—4 feet tall, and heart-shaped, acutely pointed leaves, are thickly felted with fine white hair. Each leaf is up to 10 inches long and 6 inches wide, olive green above and deep red below. Large clusters of white flowers 1- 1-½ inches wide bloom for most of the year. The petals are sprinkled with pink hairs.

B. schmidtiana is a creeping or trailing plant with fleshy, hairy stems up to 1 foot long. Heart-shaped, hairy leaves up to 3 inches long and wide are pale olive green with red vein areas above, and red underneath. Hairy, pale pink, ½ inch-wide flowers are produced continuously. B. semperflorenscultorum hybrids (often called B. semperflorens or wax begonias) are bushy plants with fleshy stems 6-15 inches tall, and waxy leaves. Leaves are roughly oval, 2-4 inches long, 1—3 inches wide, and any colour from light green to bronzy red. The male flowers are ¾-1 inch across, with either a single layer, or several overlapping layers of petals. A mass of yellow stamens is usually visible in the centre of flowers with only a few petals; in those with several layers the stamens are generally hidden behind the crowded petals. Female flowers are all single-layered, and the three-lobed ovary backing the petals looks extremely prominent. Flowers are produced continuously. They may be either white, pink or red. Popular B. semperflorenscultorum hybrids include: B. S.-c. ‘Dainty Maid’ with shiny green leaves and many-petaled, white flowers with the outer petals tipped with pink; B. S.-c. ‘Fiesta’ with green leaves, and scarlet, single-layered flowers with prominent yellow stamens in the centre of male blooms; B. S.-c ‘Gustav Lind’ with shiny green leaves and many-petaled pink flowers; B. S.-c. ‘Indian Maid’ with bronze-coloured leaves and single-layered, glowing, orange-pink flowers, with prominent yellow stamens in the male blooms; B. S.-c. ‘Pink Camellia’ with deep red-bronze leaves and many-petaled pink flowers.

B. ‘Thurstonii’ has fleshy, red stems up to 2 feet tall, sparsely covered with white hairs. The almost round, hairless, glossy leaves up to 10 inches across are bronze-green on the upper surface and bright red underneath. The summer-blooming flowers are 1- 1-½ inches across, and pink with reddish hairs.

RECOMMENDED BEGONIAS: RHIZOMATOUS

B. boweri (eyelash begonia) is a bushy, Stemless plant 6-9 inches tall. The small, heart-shaped leaves are deep emerald green, with black edging and with stiff hairs on leaf edges and leafstalks. Tiny, shell pink flowers are produced on 4- to 6-inch-long stalks in late winter and early spring. B. deliciosa has fleshy, sturdy, erect, red stems up to 2 feet high. The deeply cut, much-lobed leaves are 6-10 inches long and up to 7 inches wide. They are redtinged, olive green, heavily spotted with grey above, deep burgundy red below. The pink, 1-inch-wide, slightly fragrant flowers are produced in pairs from late summer through midwinter.

B. ‘Erythrophylla’ (also called B. ‘Feastii’; commonly known as pond-lily, kidney, or beefsteak begonia) is a hybrid up to 9 inches tall. This is an easy begonia to grow indoors. It has fleshy, shiny, almost round leaves 2-3 inches across that are olive green above, deep red below. Clusters of up to 30 light pink, ¼ inch-wide flowers are produced in late winter and early spring. Two prized variants are: B. ‘E. Bunchii’ (lettuce-leaf begonia), with leaves crested and frilled at the margins; and B. ‘E. Helix’ (whirlpool begonia), with leaves in which overlapping basal lobes are spirally curled.

B. limmingheiana (often called B. glaucophylla) is a creeping, climbing, or trailing plant with light green, waxy, oval leaves up to 5 inches long and 3 inches wide. Brick red, winter-blooming flowers are 1 inch across.

B. ‘Maphil’ (sometimes called B. ‘Cleopatra’) has many stems up to 6 inches tall, which carry star-shaped leaves 2 inches long and ½ inches wide. Deeply divided into five pointed lobes and edged with bristly hairs, these leaves have red-spotted green leafstalks covered with white hairs. Leaf colour is light chocolate brown, with major vein areas lined in greenish gold. Clusters of 10 or more pale pink flowers are produced on 12-inch-tall flower stalks in early spring.

B. masoniana (iron cross begonia) has heart-shaped leaves that are up to 6 inches long and wide, golden green, with a mahogany red, cross-shaped pattern in the centre. Leaf surfaces are puckered, and covered with fine red hairs. Greenish, 4-inch flowers with red hairs on petal undersides are comparatively rare indoors. B. rex-cultorum hybrids (king, rex, or painted-leaf begonias) are grown for their extremely decorative foliage. The true B. rex species is probably no longer in cultivation. The leaves of most forms are obliquely heart-shaped and up to 12 inches long and 10 inches wide. They have 6- to 12-inch-long leafstalks arising directly from the rhizome. Some forms have sharply cut leaf edges, others have leaf lobes that are spirally curled. All have spectacular leaf colouring. Pale pink or white flowers ½ inch across sometimes appear in summer.

There are a number of dwarf or miniature forms of B. rex-cultorum, with a height of only a few inches and leaves as little as 3 inches long. The most suitable kinds of both full-size and dwarf plants for indoor use have crisp, thick, rough-textured leaves. Among the most satisfying forms are these: B.r.-c. ‘King Edward IV,’ which has large, reddish purple leaves with paler rose-pink spots; B.r.-c. ‘Merry-Christmas,’ which has deep maroon-red leaves banded in pink, silver, and green; B.r.-c. ‘President,’ which has large, deep green leaves with extensive silver markings; and B.r.-c. ‘Salamander,’ which is a small, sturdy plant with almost totally silver leaves faintly threaded with deep green.

Proper Care:

FIBROUS-ROOTED AND RHIZOMATOUS BEGONIAS

Light Fibrous-rooted and rhizo-matous begonias grown primarily for their foliage need bright light without direct sunlight. Those grown principally for their flowers need three to four hours a day of direct sunlight.

Temperature Normal room temperatures are suitable for actively growing plants. Those that have a winter rest period should be kept at about 60°F—but not below 55°— during this period. All begonias suffer in dry air. For increased humidity stand pots on trays of moist pebbles, and suspend saucers of water under hanging baskets.

Watering Water actively growing plants moderately, allowing the top inch of the potting mixture to dry out before watering again. During any winter rest period water more sparingly, allowing the top half of the mixture to dry out between waterings.

Feeding Apply standard liquid fertilizer every two weeks to actively growing plants.

Potting and repotting Use either a peat-based potting mixture or a combination of equal parts of soil-based potting mixture and coarse leaf mold. Put an inch-deep layer of clay-pot fragments in the bottom of pots for extra drainage.

Move fibrous-rooted plants into pots one size larger every spring until maximum convenient pot size (probably 6-8 inches) has been reached. Thereafter, topdress annually with fresh potting mixture. Rhizomatous begonias have shallow roots and are best planted in half-pots or pans. Move a small rhizomatous plant into the next size pot or pan only when the rhizome has grown across the entire surface of the potting mixture; do this preferably in spring. Discard aging rhizomatous begonias in favour of attractive new plants.

When potting or repotting a begonia, simply sprinkle some mixture around the roots, and tap the container briskly to settle the mixture. Do not firm it down with the fingers.

Propagation : fibrous-rooted kinds Take 3- to 4-inch-long cuttings of non-flowering shoots in spring or early summer. Trim each cutting immediately below a leaf, carefully remove the leaf, and dip the cut end of the stem in hormone rooting powder. Plant the cutting in a 3-inch pot of a moistened equal-parts mixture of peat moss and coarse sand or perlite, and enclose the whole in a plastic bag or propagating case. Stand it in bright filtered light until renewed growth indicates that rooting has occurred (about three to six weeks). Uncover the rooted cutting, and begin to water it sparingly and to apply standard liquid fertilizer once every two weeks. Do not overwater, particularly not the hirsute begonias, which will rot if kept too wet. About six months after the start of propagation, move the young plant into a slightly larger pot of standard mixture, and treat it as a mature begonia.

Many of these begonias can also be propagated from seed. Seeds are very tiny and should not be buried when sown. Mix them with a little fine sand before sowing.

Propagation : rhizomatous kinds Cut off 2- to 3-inch-long growing tips of rhizomes and treat them like stem cuttings of fibrous-rooted specimens (see above). Or, in spring, cut a rhizome into 2- to 3-inch-long sections, each with at least one growth point and treat cut ends of sections with sulfur dust. Plant each section half in and half out of slightly moistened rooting mixture in a 3-inch pot or pan. Use a rooting mix of equal-parts peat moss and coarse sand or perlite. Place the section either horizontally or vertically, depending on how the parent rhizome was growing in its container. Enclose each planted piece of rhizome in a plastic bag or propagating case, and stand it in bright filtered light. Roots should form in four to six weeks. When two or three new leaves have appeared, uncover the little plant, repot it in an appropriate container of the recommended mixture for begonias, and treat it as a mature plant.

Most of the rhizomatous begonias named here can also be propagated every spring from leaf cuttings. (B. ‘ Erythrophylla’and B. limntingheiana are exceptions.) Take a healthy leaf with 1-2 inches of leafstalk attached, and plant the stalk at an angle of 45° in a small pot of the moistened rooting mixture recommended above (or insert several leaves in a small pan or seed tray). Enclose the whole in a plastic bag or propagating case, and stand it in bright filtered light. Rooting should occur in two to three weeks, and tiny plantlets should begin to appear from each leaf after a further two to three weeks. Several plantlets are generally clustered together. When each of them has produced at least two recognizable leaves, pot the plantlets up singly in 3-inch containers of the recommended potting mixture for mature begonias. Before treating the little plants as adults, however, dampen the mixture slightly and put the plants back in a plastic bag or propagating case for another four weeks. This will acclimatize them to normal room conditions.

Special points Some begonias— particularly B. ‘Corallina de Lucerna,’ B. metadata, and the tuberous B. suther-landii—are susceptible to attack by powdery mildew, which shows up at first as small powder-coated spots on stems, leafstalks, and leaves. As a preventive measure spray all begonias with a suitable fungicide at regular intervals.

21. November 2011 by admin
Categories: Featured Articles, Flower Arrangements, House Plants | Tags: , , , , , , , , , , , , , , , , , , , , | Comments Off on Begonia Begoniaceae

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