RUTACEAE

RUTACEAE

Systematic Position :

Class :Dicotyledonae

Sub class :Polypetalae

Series : Disciflorae

Order :Geraniales

Family :Rutaceae

Distribution :

Rutaceae comprises 150 genera and 1500 - 1600 species. The plants are widely distributed in both tropical and temperate regions. The members are abundant in South Africa and Australia. In India, the family is represented by 23 genera and over 80 species, predominantly in the tropical and sub tropical Himalayas and the western Peninsular India.

Familiar Plants :

1. Aegle marmelos Bilva or maredu

2. Atlantia monophylla Karunimma.

3. Citrus aurantium (Bitter Orange) Narinja.

4. C. aurantifolia (Sweet lime) Nimma.

5. C. limon (Lemon) Dabba.

6. C. medica (Citron, Nimbu) Madiphalamu

7. C. sinensis (Sweet Orange) Battai.

8. C. reticulata (Loose skinned orange, Santra) Kamala Phalam.

9. C decumara (= C. grandis) Shaddock, Pomelo, Pampara Panasa

10  Feronia elephantum (= Limonia acidissima, Wood apple) Velaga.

11. Murraya koenigii (Curry leaf) Karivepaku.

12. M. paniculata (=M. exotica, Orange jasmine). Pooveiaga

13. Naringi crenulata(= Limonia crenulata) Torra velaga.

14. Ruta graveolens (common rue) Sadapaku

15. Toddalia asiatica (Wild Orange Tree).

16. Chloroxylon swietania (Satin wood) Billukarra.

Habit :

The members are mostly shrubs or small trees, cultivated for their fruits. Herbs are rare (Ruta).

Aegle marmelos and Feronia elephantum are large sized trees.

Murraya exotica is an ornamental shrub with scented flowers. The leaves and bark of the trees are often fragrant due to the presence of oil glands.

Vegetative Characters:

1. Root System : Tap root system, often infected mycorrhizae.

2. Stem : Usually erect, woody, branched, armed with spires or unarmed (Murraya, Evodia). Young shoots are gland dotted.

3. Leaf : Alternate, less frequently opposite (Toddalia), simple, more often pinnately compound as in Murrava. In Citrus sp. leaves are unifoliate with a joint at the junction of leaf blade and winged petiole. In Aegle the leaves are trifoliate. Leaves are typically gland dotted. In many genera, the first leaf of axillary bud modifies into spine.

Floral Characters:

1. Inflorescence : Flowers are clustered into axillary (Citrus Murraya) or in terminal cymes (Clausena, Skimmia) or panicles( Murraya exotica). In some species of Citrus and Triphasia, flowers are axillary and solitary.

2. Flower : Bracteate, bracteolate, pedicellate or sub sessile, complete, bisexual, actinomorphic, hypogynous and pentamerous. A distinct nectar secreting disc is present at the base of the ovary. Flowers are rarely unisexual as in Toddalia, Evodia etc. or may be polygamous as in Feronia. In Ruta, the lateral flowers are tetramerous, while the terminal one is pentamerous.

3. Calyx : Sepals usually five and polysepalous, green in colour and gland dotted. Sometimes 4 or 3 sepals are also found. In zygomorphic flowers, the calyx becomes either tubular or cup shaped. The aestivation is either imbricate or valvate.

4. Corolla : Petals normally five in number, but may be four or three in some members. Petals polypetalous, but gamopetalous condition is seen in Correya (Australia) and Galipea. (America) Aestivation is valvate or imbricate, petals gland dotted and sweet smelling, variously coloured.

5. Androecium : There is great variation in the number of stamens. They may be as many as the number of petals, or twice the number of petals. Stamens 8 - 10, arranged in two whorls. The outer whorl lie opposite to petals and the inner whorl alternates with the outer whorl. This arrangement is known as Obdiplostemonous.

Stamens are some times numberous. In Aegle marmelos upto 60 stamens are present. In Murraya 10 stamens are Present in 5+5 arrangement; stamens are 5 arranged one whorl in the male flowers of Toddalia and Evodia. The anthers are dithecous, basifixed and introse. The connective is usually glandular at the apex.

6. Gynoecium : Ovary superior, manocarpellary (Empleurum), bicarpellary (Murraya) , tricarpellary (Triphasia) , pentacarpellary (Citrus spp.) and syncarpous. Ovary bilocular to Multilocular, or unilocular as in Feronia. Placentation is usually axile, rarely parietal (Feronia), Ovules anatropous. Styles as many as carpels, free or variously united. Stigma terminal, entire or lobed.

7. Fruit : Usually a fleshy berry and is called Hesperidium in Citrus spp. In Aegle marmelos and Feronia the berry is large with a hard epicarp. In Acronychia the fruit is a capsule.

8. Seed : Seeds are generally endospermic, with a straight or curved embryo. Polyembryony is a very common feature of Rutaceae.

9. Pollination : Usually entomophilous. The coloured petals, strong scent, nectar are the sources of attraction for the insects. Cross pollination is favoured by marked protandrous condition of flowers.

Floral formula :

Economic Importance :

The family is of great economic value.

1. Edible fruits : The most important genus of the family, citrus provides various edible fruits like oranges, limes and lemons. They have medicinal value.

(i) Citrus aurantifolia - lime

(ii) C. aurantium - Sour Orange

iii) C. sinensis - Sweet Orange or mausambi

iv) C. limon - lemon.

(v) Aegle marmelos - Wood apple.

vi) Feronia elephantum - Elephant apple.

2. Volatile Oils :

(i) Ruta graveolens : 'oil of rue'- is distilled from leaves and young shoots and is used in perfumery and flavourings.

(ii) Boronia megastigma : 'oil of Boronia' is, distilled from shoots, used in perfumery.

(iii) Amyris balsamifera: Source of a scented oil called West Indian Sandalwood oil.

(iv) Amyris plumieri : ‘Mexican elemi’, an oleoresin is obtained from the bark, Which is used in lacquers.

3. Ornamental Plants :

1. Murraya exotica (Marua)

2. Ruta graveolens (Garden rue)

3. Calodendrum

4. Dictamnus albus

5. Xanthophylum.

6. Toddalia.

7. Atlantia.

4. Other Uses :

1. The leaves of Murraya koenigii are aromatic and are used in flavouring curries.

2. The wood of Chloroxylon swietenia is known as Indian Satin wood and used in making furniture.

3. Timber from Flindersia brayleana is an important hard wood from Australia.

4. Cusparia febrifuga gives 'cusparia bark' which is used as a substitute for quinone.

5. The twigs of Glycosmis pentaphylla and Zanthoxylum alatum are used as chewsticks or tooth brushes in Indochina and Malayasia.

6. The roots of Toddalia asiaticar a spiny shrub, are the source of a yellow dye.

         The family Rutaceae is closely related to Meliaceae Sapindaceae and Anacardiaceae in their external and anatomical features. (heath – like habit, leaf structure, disc formation an obdiplostamonous stamens). Some botanists relate Rutaceae to Euphorbiaceae on account of the ventral raphe in ovule (in some  genera).