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In this article we will discuss about the classification of Commelinidae:- 1. Commelinaceae 2. Zingiberaceae.
Family # 1. Commelinaceae:
Salient Features of Commelinaceae:
Commelinaceae or the spiderwort family, is the largest family of the order, containing 652 species in 50 genera. They are tropical and subtropical in distribution. In India 11 genera and 75 species are found. Commelina has 200 species, Tradescantia (Spiderwort) with 65 species, Zebrina (Wandering jew) with 4 species and Rhoeo (bulrushes) with one species is prominent.
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Vegetative Characters of Commelinaceae:
Generally herbs annual or perennial, sometimes woody at the base. Roots fibrous or tuberous; stem twining (Sireptolirion), with purplish tinge (Commelina) or deep violet (Tradeosantia). Stem with prominent nodes and internodes.
Leaves:
Simple alternate, distichous or spirally arranged, sessile or petiolate, leaf sheath prominent, open or closed, leaf blade simple, entire, Linear ovate-lanceolate, parallel.
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Floral Characters of Commelinaceae:
Inflorescence:
Umbellate cyme subtended by two large spathaceous bracts (Tradescantia), or solitary, usually of cicinni in panicles, sometimes shortened into heads, sometimes sessile with flowers fascicles. Sometimes axillary and penetrating enveloping leaf sheath, when solitary they are terminal or axillary.
Flower:
The flowers are ephemeral, lack nectar, and offer pollen as a reward to their pollinators. Pedicellate, Bracteate, bract spathaceous, actinomorphic or zygomorphic, (Commelina), Bisexual, or andromonoecious, trimerous, hypogynous, blue or white. In Commelina some flowers are also subterranean and cleistagamous.
Calyx:
3 sepals, free, imbricate, sometimes connate only at the base, often boat shaped or carinate, sometimes galeate at apex.
Corolla:
Generally 3 petals or sometimes polypetalous, 2 fused or connate and tubular at the middle and free at 2 ends (Cyanotis), sometimes clawed.
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Androecium:
6 stamen, 3+3 (in two whorls), free rarely fused, all or only 2 or 3 fertile, 2 fertile stamen and 4 staminodes in Aneilema; 3 stamen and 3 staminodes in Commelina 5 stamen and one staminode in Floscopa.
All six fertile stamen in Tradescantia, Filaments glabrous or torulose, villous, different length and curved, anther parallel or slightly divergent, longitudinally dehiscent, rarely dehiscent by apical pores, Staminodes— 1-3 antherodes 4 lobed and butterfly like, 3-sect, 2-lobed and dumbbell- shaped, or entire.
Gynoecium:
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Tricarpellary syncarpous superior, axile placentation, triloculae or may be reduced to two locules, ovules one to many per locule, orthotropous, style one and stigma one.
Fruit:
Loculicidal capsule, or 2-3 valved capsule, rarely baccate and indehiscent.
Seeds:
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Few, large, arillate, endosperm copious, hilum orbicular or linear.
Economic Importance of Commelinaceae:
1. Aneilema somaliense— Roots used for piles and Asthama.
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2. Commelina benghalensis— Rhizome edible
3. Commelina obliqua— Roots antidote of snake poison.
Ornamentals:
4. Callisia elegans— Striped inch plant
5. Callisia fragrans—Basket plant
6. Callisia repens — Creeping Basket plant
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7. Commelina coelestis — Blue spiderwort
8. Cyanotis kewensis — Teddy Bear vine
9. Cyanotis somaliensis — Furry kittens, Pussy ears.
10. Dichorisandra chyrsiflora — (Blue ginger, Brazilian ginger)
11. Rhoeo spathacea— Moses-in-the-boat, oysterplant.
12. Setcreasea pallida — Purple heart, Wandering jew
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13. Siderasis fuscata — Brown spiderwort, Bear ears.
14. Tradescantia fluminensis — Wandering jew.
15. Tradescantia navicularis — Chain plant.
16. Tradescantia sillamontana — White valvet.
17. Tradescantia virginiana — Virginia spiderwort
18. Tradescantia zebrina — White flowered wondering jew.
Systematics and Taxonomy:
The family has always been recognized by most taxonomists. The APG II system of 2003 also recognizes this family and assigns it to the order commelinales in the clade commelinids.
Kingdom: Plantae
Unranked: Angiosperms
Unranked: Monocots
Unranked: Commelinids
Order: Commelinales
Family: Commelinaceae.
Family # 2. Zingiberaceae:
Salient Features of Zingiberaceae:
It is largest family of order Zingiberales with approximately 52 genera and over 1300 species. Gingers are found throughout the tropics, but are especially abundant in Southeast Asia. The aromatic herbs grow in moist areas of the tropics and subtropics including some regions that are reasonably dry.
Gingers are distinguished by the presence of labellum, formed by the fusion of two sterile stamens and by the presence of essential oils in their tissues. They are commonly used as ornamentals, as spices, and for medicinal properties.
Vegetative Characters of Zingiberaceae:
Members of the family are perennials that frequently have sympodial (forked) fleshy rhizomes. They may grow to 6m (20′) in height. Thick jointed branches pseudostem is found is Curcuma. A few species are epiphytic and have aerial roots exposed to the humid atmosphere.
Leaves: Spiral (Cortus) Stalks, sheathing leaf base, long sheath is the ligule which is of various shapes and sizes, blade is lanceolate, ovate with a mid rib.
Floral Characters of Zingiberaceae:
Inflorescence:
Branched spike or raceme, terminal or monochasial cyme and subtended by conspicuous spirally arranged bracts.
Flower:
Bracteate, ebracteate, zygomorphic or actinomorphic, bisexual, trimerous and epigynous. Bracts (leaflike structure) are spiraly arranged and the flower clusters are spiral and cone like.
The Zingiberaceae have brightly coloured flowers, may bloom for only a few hours and are thought to be pollinated by insects. Etlingera exhibits an unusual growth pattern. The floral parts grow below the ground except for a circle of bright red petal-like structures that emerges from the ground, yet the leafy shoots rise to 5m.
Perianth:
6 tepals, 3+3 in two whorls fused tubular calyx and a tubular corolla with one lobe larger than the other two. Commonly green sepals differ in texture and colour from the petals.
Androecium:
6 stamen— 3+3 in two whorls, suppressed in Cortus 2 lateral leafy staminodes and anterior suppressed inner whorls like Orchid. It also has labellum with two or three fused stamens joined with a pair of petal like stamens. Nectar is present in the slender floral tube.
Gynoecium:
Tricarpellary, syncarpous, inferior, trilocular, axile placentation rarely parietal placentation, stigma projects beyond the anthers funnel Shaped, a pair of nectar secreting epigynous glands present.
Fruit:
Loculicidal capsule.
Economic Importance of Zingiberaceae:
Many species are economically valuable for their spices and perfume.
1. Curcuma longa — Turmeric (Haldi), dried thick rhizome is turmeric. It yields a, yellow dye, medicinal use and spice.
2. Elettaria cardamomum — Cardamom (elaichi), Seeds are edible.
3. Zingiber officinale — Ginger (Adrak). Rhizomes edible.
4. Alpina galanga — Shell flower (Kulanjan). Thai ginger or galangal. Cultivated as ornamental and dried rhizome is medicinal.
5. Hedychium ceronarium — Ginger lily, paper from aerial beautiful flowers used in garlands stems and other decorations.
6. Amomum subulatum — Cardamom (Badi elaichi) —used as spice.
7. Curcuma alismatifolia — Ornamental
8. Zingiber mioga— Myoga. Ornamental
9. Kaempferia — Ornamental
10. Nicolaia — Terch ginger — Ornamental
11. Aframomum melegueta — Melegueta pepper.
Systematics and Taxonomy:
Kingdom: Plantae,
Unranked: Angiosperm,
Unranked: Monocots,
Unranked: Commelinids,
Order: Gingiberales (zingiberales), and
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Family: Gingiberaceae (zingiberaceae).
The family is divided into four subfamilies and then tribes.
Subfamily 1. Siphonochiloideae:
Tribe— Siphonochileae e.g. Siphonochilus
Subfamily 2. Tamijioideae:
Tribe — Tamijiae e.g. Tamijia
Subfamily 3. Alpinioideae:
Tribe 1. Alpinieae
e.g. Alpina, Amomum, Elettaria, Renealmia, Aframomum
Tribe 2. Riedelieae
e.g. Riedelia, Siamanthus
Subfamily 4. Zingiberoideae:
Tribe 1. Zingibereae.
e.g. Hedychium, Kaempferia, Curcuma, Curcumorpha, Zingiber
Tribe 2. Globbeae e.g. Globba, Gagnepainia.
