This document provides information about the plant family Rutaceae (citrus family). It discusses the general characteristics of the family including their distribution in tropical and temperate regions. Key features include hermaphrodite flowers with a disc below the ovary, 10 stamens in an obdiplostemonous arrangement, and a superior ovary. The family includes trees, shrubs, and few herbs. Many members have aromatic leaves and fruits valued for their vitamins and essential oils. Specific details are provided about Citrus aurantium describing its morphology.

1. PLANT TAXONOMY
RUTACEAE(Citrus Family)
Presented by:
P.Bhanu Kiran

2. GENERAL INFORMATION
• The family is commonly is called orange family.
• The family comprises 150 genera and 1300 species out of which India
contributes 71 species.
• The members of the family are distributed in tropical and temperate regions
and they are predominant in South Africa and Australia.

3. CHARACTERS
• Leaves, simple or compound.
• Flower hermaphrodite, hypogynous, actinomorphic with a disc below the ovary.
• Corolla polypetalous.
• Stamens ten, obdiplostemonous.
• Carpels 5 or many, ovary superior, multilocular.
• Fruit capsule or berry.
• Aromatic odour is present.

4. AFFINITIES
• Engler and Prantl included the family in the Geraniales along with Zygophyllaceae,
Euphorbiaceae and Burseraceae.
• Hallier attached particular phylogenetic significance to the Rutaceae and derived it
from stocks ancestral to Berberidaceae.
• Rendle placed the family in a separate order between Geraniales and Sapindales.
• Wettstein included Rutaceae along with Meliaceae in the order as Terebinthales

5. • Rutaceae is related to the Meliaceae, Sapindaceae and Anacardiaceae in habit, leaf
structure, presence of disc around the ovary and obdiplostemonous condition of
androecium.
• The family Rutaceae is also related to Euphorbiaceae on account of the presence of
ventral raphe of the ovule in some genera.
• According to Tillson and Bamford (1938) the disc in the members of sub-family
Aurantioideae represents the vestigeal third whorl of stamens.

6. VEGETATIVE CHARACTERS
Habit:
• The plant are generally shrubs (Murray a, Limonia, Zanthoxylum), trees (Aegle,
Citrus, Feronia), rarely herbs (Ruta graveolens) with strong fragrance Paramignya is a
shrub but climbs by means of axillary thorns.
Root:
• Tap root, branched often infected with fungus.
Stem:
• Woody (Citrus, Feronia), erect, cylindrical, branched, solid often thorny (Citrus),
gland dotted.

7. Leaves:
• Alternate (Citrus, Murraya) or opposite (Evodia), petiolate, petiole may be winged
(Citrus aurantium), simple or compound-pinnate (Murraya), palmate (Aegle and
Citrus) smooth gland dotted, glands with essential oils, exstipulate, margin entire
serrate, unicostate reticulate venation. In Citrus petiole is winged.

8. FLORAL CHARACTERS
Inflorescence:
• Usually cyme or axillary or terminal corymb (Murraya paniculata) some times
racemose or solitary.
Flower:
• Pedicellate, ebracteate, hermaphrodite, or unisexual (Zanthoxylum, Evodia, Feronia),
actinomorphic rarely zygomorphic (Dictamnus and Correa), hypogynous, complete,
pentamerous or tetramerous (Acronychia and lateral flowers of Ruta).
Calyx:
• Sepals 5 or 4, free or fused; in zygomorphic flower it becomes gamosepalous and
tubular; imbricate; sometimes deciduous.

9. Corolla:
• Petals 5 or 4, polypetalous rarely gamopetalous (Correa speciosa) or absent
(Zanthoxylum), variously coloured, imbricate.
Androecium:
• In majority of cases the stamens are obdiplostemonous and 10 in number; in
numerous stamens with polyadelphous condition; in Zanthoxylum 3 stamens and
Skimmia 5 stamens; anthers introrse, dithecous, basifixed or versatile.

10. Gynoecium:
• Pentacarpellary and only slightly united at the base or the sides forming a deeply
lobed ovary with fused styles originating from the centre. In Citrus and Toddalia
carpels are fully united. In Feronia the carpel is only one celled with many parietal
placentae. In other genera the placentation is of the axile type. Topically the ovary
superior with a prominent nectariferous disc below it. Ovule anatropous.

11. Fruit:
• In Flindersioideae there is septicidal or loculicidal capsule; in Toddalioideae a
drupaceous fruit; hesperidium in Citrus and berry in Murraya.
Seed:
• Endospermic or exalbuminous.
Flower formula

12. FLORAL DIAGRAM

13. ECONOMIC IMPORTANCE
• Fruits are rich in various vitamins, provide essential oils, purifies blood, reduces thirst
and various parts of some plants are used medicinally.
• Also used as ornamentals.

14. CITRUS AURANTIUM
Habit:
• A small tree, cultivated for fruit.
Root:
• Tap- root, branched, perennial.
Stem:
• Erect, branched.
Leaf:
• Evergreen, cauline and ramal, alternate, petiolate, petiole winged, exstipulate,
compound, terminal leaflet unicostate reticulate, gland-dotted and odorous,
glaucous. A spine in the axil of each leaf is the modified first leaf of the axillary
suppressed shoot

15. • Inflorescence:
• Raceme.
• Flower:
• Ebracteale, complete, hermaphrodite, regular, actinomorphic, hypogenous.
• Calyx:
• Five, gamosepalous, sepals gland-dotted, pentafid, greenish, inferior.
• Corolla:
• Five, polypetalous, petals lanceolate, gland-dotted, white imbricate, alternating
the sepals, inferior.

16. Androecium:
• Stamens numerous in one whorl, polyadelphous, filaments united into groups at
base, anthers dorsifixed, introse, inferior.
Gynoecium:
• Polycarpellary syncarpous, ovary superior, multilocular, ovules many; axile
Placentation; style short; stigma capitate a large honey- secreting disc below the
ovary.
Fruit:
• Berry
Seeds:
• Numerous, ex-albuminous, testa mucilaginous