In this article we will discuss about:- 1. Characters of Zingiberaceae2. Distribution of Zingiberaceae 3. Economic Importance 4. Affinities 5. Important Type.
Characters of Zingiberaceae:
Presence of aromatic oils, ligule, marked differentiation of perianth into calyx and corolla, single stamen and large usually petaloid staminodium.
A. Vegetative characters:
Habit:
Perennial, aromatic herb.
Root:
Adventitious, rarely fibrous.
Stem:
Rhizome-tuberous or horizontal, rarely aerial, bracted, scapose or leafy, short or elongated. In Curcuma the aerial stem is very short or even absent; sometimes formed by the rolled up leaf sheaths.
Leaf:
Radical or cauline; exstipulate; petiolate or sessile; leaf base sheathing in some (Curcuma); ligulate; two-ranked, spiral in Costus; simple; entire; elliptical or linear or lanceolate; apex acute or obtuse; parallel unicostate.
B. Floral characters:
Inflorescence:
Terminal spike or racemose or panicle.
Flower:
Bracteate; pedicellate or sessile; complete; zygomorphic; irregular; bisexual; epigynous; cyclic; calyx and corolla are distinct; flowers usually large in size and brightly coloured, aromatic, except in Costus, Monocostus, Dimerocostus and Tapeinocostus.
Calyx:
Sepals 3; gamosepalous; tubular or spathe like; generally 3-toothed; green; superior. In Globba the calyx tube is very short; odd sepal anterior.
Corolla:
Petals 3, free or more or less united; tubular or funnel-shaped; three-lobed, lobes unequal; linear or broad. In Roscoea the corolla tube is long and slender with upper lobe broad, cucculate, and erect, the two lateral lobes spreading and narrower. Corolla tube as long as or longer than the calyx tube.
Androecium:
Stumens six, arranged in two whorls, the posterior stamen of the inner whorl is fertile and epipetalous and antipetalous, the other two stamens of the inner whorl are sterile and mostly petaloid and are fused together to form the petaloid lip or labellum , which may be two or three lobed (it is not equivalent to the labellum of Orchidaceae).
The anterior stamen of the outer whorl is always absent, the other two may be absent (Renealmia) or may be present as large leafy staminodes right and left of the fertile stamen. In Curcuma, Roscoea and Zingiber the two anther lobes are joined by a long spurred connective, the spurs standing above the lip; in Roscoea the connective has two basal spurs.
Gynoecium:
Tricarpellary; syncarpous; inferior; trilocular with axile placentation (Zingiber; Curcuma, Hedychium, Roscoea, Amomum etc.); ovules many and superposed in each loculus; in Globba the ovary is unilocular with parietal placentation; in Monocostus the ovary is bilocular with parietal placentation (third loculus is suppressed); in Haplochorema the ovary is unilocular with a few basal ovules. Ovules are usually anatropous or semi-anatropous. Style one, simple, usually slender; stigma simple and capitate or three lobed.
Fruit:
Loculicidal capsule, opening by three valves.
Seed:
Endospermic.
Pollination:
Entomophilous.
Floral formula:
Distribution of Zingiberaceae:
Zingiberaceae consists of 49 genera and about 1300 species, out of which about 17 genera and 115 species have been reported from India. The measure of family are distributed through the eastern hemisphere, particularly in Indo-Malayan area.
Economic Importance of Zingiberaceae:
1. Food:
The commercial ginger (H. Adarak) is prepared from the aromatic creeping, thick jointed branching root-stocks of Zingiber officinale. The ginger is used as spice & in perfumary.
The turmeric (H. Haldi) is obtained from rhizomes of Curcuma longa and curcuma domestica and used as spice.
Elettaria cardamomum yields cordamon or Chhoti-Elayachi is a valuable condiment Amomum subulatum (H. Bari-elaychi) also yields a valuable condiment and spice.
2. Medicinal:
The powder of Curcuma longa is applied externally in sprains and wounds. It is used in many Ayurvedic medicines. Zingiber officinale are Elettaria cardamomum are used in medicine – as carminative. Zeodary is used as tonic.
3. Perfume:
Zingiber officinale, Elettaria. spps, Abir – a scented powder obtained from roots stock of Hedychium spicatum.
4. Ornamental:
Costus, Globba, Hedychium coronatum, Alpinia, Brachychilum, Roscoea etc. are cultivated in gardens and green houses for decorative purposes.
Affinities of Zingiberaceae:
It is closely related to Musaceae in habit, zygomorphic flowers and inferior ovary.
Common plants of the family:
1. Alpinia galanga – garden plant with scented flowers.
2. Curcuma amada – Mango ginger-rhizomes having the smell of mango.
3. Costus speciosus – a plant of shady waste places.
4. Globba bulbiflora – a plant of marshy places and river-banks.
Division of the family and chief genera:
The Zingiberaceae is divided into two subfamilies, one with no tribe and the other with three tribes:
Sub-family I. Costoideae:
Upper parts of the plant not aromatic. Leaves spiral. Lateral staminodes small or absent. Nectaries replaced by septal glands. Example: Costus.
Sub-family II. Zingiberoideae:
Plants aromatic. Leaves distichous. Lateral staminodes large, small or absent.
Tribe (i) Globbeae:
Lateral staminodes of outer whorl petaloid. Ovary unilocular; placentation parietal. Example: Globba.
Tribe (ii) Hedychieae:
Lateral staminodes of outer whorl petaloid and conspicuous. Ovary trilocular. Examples: Curcuma, Hedychium, Kaempferia etc.
Tribe (iii) Zingibereae:
Lateral staminodes of outer whorl linear, teeth-like or absent. Ovary trilocular. Examples: Ammomum, Elettaria, Zingiber, etc.
Important Type of Zingiberaceae:
Zingiber officinale (Ginger) (Fig. 104.1):
Habit:
A perennial herb.
Root:
Adventitious.
Stem:
Underground rhizome with aromatic smell.
Leaf:
Simple, petiolate or sessile, entire, linear, lanceolate, ligule is present.
Inflorescence:
Solitary in heads (spikes).
Flower:
Zygomorphic, bracteate, bisexual, epigynous.
Calyx:
Sepals 3, gamosepalous, superior odd sepal anterior,
Corolla:
Petals 3, more or less united, tubular, toothed.
Androecium:
6 stamens in 2 whorls, only median posterior stamen of inner whorl is functional and epipetalous; the other 2 stamens of inner whorl united to form a 2-lipped staminode or labellum; the stamens of the outer whorl are modified into staminodes.
Gynoecium:
Tricarpellary, syncarpous, ovary inferior, trilocular or unilocular, axile placentation; style 1; stigma 1, the slender style held in a groove in the fertile stamen.
Fruit:
Capsule.
Seed:
Many, endospermic, arillate.
Floral formula:
