Monocotyledon families- Orchidaceae, Iridaceae and Amaryllidaceae

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Orchidaceae
(Orchid family)



Orchidaceae is one of the largest families of the flowering plants, represented by about 1000 genera and 20,000 species which are cosmopolitan but primarily distributed in tropical areas. Its members are rare in arctic regions. In Indian flora this is the second largest family represented by about 130 genera and over 880 species distributed mainly in eastern Himalayas, western Ghats and Khasia hills.
This is the family of greatest variety of flowers among flowering plants. Orchid flowers are known for their strange shape, longevity and beautiful look. 
Selected Indian genera are:
    •  Cattleya, 
    • Cymbidium, 
    • Cypripedium, 
    • Dendrobium, 
    • Habenaria, 
    • Orchis, 
    • Vanda and 
    • Zeuxine.
                   Plants of this family are mostly perennial herbs; perianth inconspicuous; leaves 2-ranked; flowers zygomorphic, usually trimerous; usually labellum, pollinia and gynostegium present; ovary inferior.
General habit: Perennial herbs; either terrestrial (Orchis), epiphytic (Cattleya, Cypripedium) or saprophytic (Neottia); orchids in temperate regions are mainly terrestrial while those in tropical regions are mainly epiphytic; sometimes climbers (Bulbophyllum, Vanilla); often with fibrous or tuberous roots or rhizomatous; epiphytic orchids usually contain fleshy pseudobulbils consisting of one or more thickened internodes of stem; aerial roots often contain velamen; mycorrrhiza often present; stems leafy or scapose, may be sympodial (Dendrobium) or monopodial (Vanda); saprophytic forms usually devoid of chlorophyll (Corallorhiza, Neottia).
Perianth: Usually 6 tepals in 2 whorls of 3 each; the outer whorl (representing calyx) of 3 tepals is green or coloured; the inner whorl (representing corolla) is petaloid, of these the posterior teal is  highly modified, often projected basally into a spur and called labellum or lip.
Labellum is strictly the uppermost petal but looks as if located on the lower side of the flower in most orchids. This is caused either by the twisting of the ovary through 180 degrees (as in many orchids), or by the pedicel bending back over the apex of the stem (as in single-flowered orchids). This phenomenon is called resupination. It enable the labellum to work as a landing place for pollinating insects.
Pollination: Flowers of Orchidaceae are well adapted for insect pollination because of several characters, such as large sized and gaudy perianth, pleasant smell and presence of nectar secreted in nectary or sac-like rostellum. The flowers are protandrous. When an insect enters the flowers, the pollinia get attached to its body by their caudicles. When this insect visits another flower, it may deposit the pollen grains on its stigmatic surface below the rostellum, thus completing the process of pollination.

Economic Importance
    1. The fruits  of climbing genus Vanilla fragrans syn. V. planifolia are the source of highly fragrant extract used in perfumery and confectionery.
    2. Tuberous roots of Habenaria Susanna and Orchis latifolia are edible and eaten during scarcity.
    3. Starchy tubers of some genera (Cymbidium, Dactylorhiza, Eulophia, Orchis, etc.) are dried to form 'Salep' of commerce, used for culinary medicinal purposes.
    4. Orchids are known throughout the world for their beautiful flowers of various forms, shapes and highly attractive colours. Some orchid genera commonly grown in glasshouses are Cattleya (florist's orchid), Cymbidium, Cypripedium (lady's slipper), Dendrobium, Epidendrum (green-fly orchid), Habenaria (fringe orchid), Miltonia, Odontoglosssum (baby orchid), Oncidium (butterfly orchid), Orchis (showy orchid), Paphiopedilum, Phalaenopsis, Vanda, Vanilla and Zeuxine.











Iridaceae
(Iris family)

Saffron plant


                            




A family of about 70 genera and 1,500 species, Iridaceae are distributed in both tropical and temperate regions with chief centres of distribution in tropical America and South Africa. Chief areas of distribution in India are Kashmiri and Kumaon hills. 
Selected Indian genera are: 
    • Belamcanda chinensis, 
    • Crocus sativus, 
    • C. biflorus, 
    • C. speciosa, 
    • Gladiolus primulinus, 
    • G. colvillei, 
    • Freesia refracta, 
    • Iris kumaonensis, 
    • I. germanica and 
    • I. foetidissima. 
    • Iridiaceae are cultivated throughout the world for their beautiful flowers. 
          Perennial herbs with roots produced from corm (Crocus), bulb (Gladiolus), or rhizome (Iris, Belamcanda); very rarely subshrubs; stems solitary or several, or plants scapose. They contain equitant leaves; flowers trimerous with 3 petaloid sepals and 3 petals; stamens 3; ovary inferior. 
Perianth: Usually 6 tepals arranged in 2 whorls of 3 each; of these the outer whorl of 3 tepals represents calyx and often petaloid, and the inner whorl of 3 tepals represents corolla, tepals of both the whorls are often distinguishable from each other by colour, size, or texture; free or united, but usually basally connate into a long tube (Crocus). Pollination usually entomophilous effected by bees and butterflies.

Economic Importance
    1. Dried styles of Crocus sativus are used to make "saffron", an orange-yellow dye used chiefly for flavouring and colouring dishes. Saffron is also used to give colour to cooked rice. 'Around 100,000 styles are required to produce 1 kg of saffron'.
    2. Orrisroot used in perfumes and in dentifrices, is obtained from the rhizomes of Iris germanica var. florentina.
    3. Roots of Belamcanda chinensis are an antidote to snake poison.  A drug obtained from its rhizomes is used in tonsillitis.
    4. Roots of Iris germanica are diuretic and used in diseases of gall bladder.
    5. Iridaceae are highly-prized decorative plants of gardens and parks. Some of these ornamental genera are: 
    • Belamcanda (blackberry lily), 
    • Crocosmia, 
    • Crocus, 
    • Dierama, 
    • Freesia, 
    • Gladiolus, 
    • Iris, 
    • Ixia, 
    • Romulea, 
    • Sisyrinchium (blue eyed grass), 
    • Tigridia (tiger flower) and 
    • Tritonia.





Amaryllidaceae
(Daffodil family)


A family of about 85 genera and over 1100 species, Amaryllidaceae are usually distributed in tropical and subtropical regions. About 9 genera and over 60 species have been reported from India. 
Some larger genera from world over are: 
    • Crinum, 
    • Hippeastrum, 
    • Narcissus, 
    • Hymenocallis, 
    • Haemanthus, 
    • Cyrtanthus, 
    • Zephyranthes, 
    • Galanthus and 
    • Pancratium. 
Selected Indian genera are: 
    • Agave, 
    • Crinum, 
    • Narcissus and 
    • Zephyranthes.
Plants of this family are usually perennial, bulbous (Crinum) or rhizomatous (Hypoxis), xerophytic herbs leafing only in the rainy or spring seasons; some are arborescent (Agave, Furcraea). Inflorescence usually a leafless scape or umbel subtended by spathe-like bracts; perianth gamophyllous and epiphyllous; ovary inferior. Inflorescence appear after several years in Agave. Pollination is entomophyllous. Insects are attracted because of gaudy coloured, often scented perianth and presence of nectar. Nectar is secreted in the inner tepals in Galanthus and in corona in Narcissus, Hippeastrum, etc.


Economic Importance

Ornamental plants:
    • Agave americana (century plant)
    • A. mexicana
    • A. vera-cruz
    • Alstromeria aurantiaca
    • Amaryllis belladona (Amaryllis)
    • Chidanthus fragrans
    • Clivia miniata (kafir-lily)
    • Crinum asiaticum 
    • C. defixum
    • C. latifolium
    • Curculigo capitulata
    • C. latifolia
    • Eucharis grandiflora (Amazon lily)
    • Galathus nivalis
    • Haemanthus cockiness (blood lily)
    • Hippeastrum vittatum
    • Hymenocallis americana (spider lily)
    • Hypoxis hirsuta (stargrass)
    • Leucojum vernum (snowflake)
    • Narcissus pseudo-narcissus (Daffodil or nargis)
    • N. bulbocodium
    • N. gazette
    • Nerine filifolia
    • Pancratium maritinum
    • Polianthes tuberosa (Tuberose)
    • Zephyranthus grandiflora (Zephyr lily)
    • Z. candida
    • Z. tubispatha
Oil obtained from the flowers of several species of Narcissus and Polianthes are used in high grade perfumery.

Fibres obtained from Agave cantata, A. sisalana (sisal hemp), A. vera-cruz and Furcraea foetida (Mauritius hemp) are used for making cordage, mats, socks, shoe soles, ropes, twines, etc. The fibres obtained from the leaves of Cuculigo latifolia are used for making fishing nets.

Fruits of Curculigo latifolia and roots of C. orchioides and Alstroemeria are ground and eaten as flour.

Tubers of Curculigo orchioides are used in treatment of asthma and jaundice.








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