Foreword The Indian floristic diversity illustrates 17,500 Angiosperm species belonging to 4,000 genera of 315 families which include over 5000 endemic taxa. India is one of the twelve centres of diversity of crop plants of the world. It has domesticated about 152 species including vegetables, fruits, ornamentals, plantation crops, spices, medicinal plants, aromatic plants and industrial crops. By 2012, India alone requires 200 million tonnes of vegetables and 180 million tonnes of fruits to meet the nutrient requirements of an estimated 1250 million people. Production of traditional fruits and vegetables alone will not meet the nutrient demand. Growing of vegetables, fruits, ornamental plants and commercial crops as well as underutilized and underexploited crops like Atuna, Azafran de Bolta, Capers and Caper plants and Kair have become relevant to enlarge the biosphere flora. Demand for natural dyes is increasing with the awareness of negative effects of synthetic dyes and pigments. Under- exploited fruits like bael, carambola, Citrus species, fig, hog-plum and tropical plum need scientific attention for improvement. These fruits have traditional uses in ethnic medicines, food and preserves. Leaf vegetables provide much needed minerals, vitamins and   fibre. Oriental pickling melon, snapmelon, spinegourd, tinda, pointed gourd and ivygourd are cucurbits with potential nutrient value. Agathi, chekkurmanis, edible begonias, Kang Kong and Colocasia leaf are leaf vegetables not fully utilized. Tree tomato is a delicate fruit vegetable. There are palms like palmyrah with potential to grow exclusively under arid and rainfed conditions. The volume 3 of Underexploited and Underutilized Horticultural Crops consists of 24 chapters, each chapter contributed by working scientists in the concerned crop(s). Forty eight eminent Botanists from 7 countries have contributed very informative chapters. The contributors include Prof.Ghillean T.Prance FRS, a world authority on Atuna. I congratulate Dr.K.V.Peter, Professor of Horticulture and former Vice Chancellor, Kerala Agricultural University, for editing this volume. I also compliment M/s New India Publishing Agency, New Delhi for undertaking the publication.

Atuna racemosa subspecies racemosa is shown to be a species with many uses throughout its range from Malaysia to Melanesia. The principle uses described are the seed oil used as anti-inflamatory massage oil and for hair dressing, the seed pulp that is used for caulking and varnishing boats, the wood for house construction, and many parts of the plant as ingredients of local medicines. The medicinal uses of this species deserve further study since it has been shown to have both anti-bacterial and anti-inflamatory action. It is also uncertain whether its distribution over the Pacific is natural or human caused. Atuna racemosa Rafin. is a widely distributed tree species that ranges from the Malay Peninsula through Malesia, Australasia and to the Pacific islands as far as Fiji, Tonga and Samoa. As with many useful plants, its natural distribution is uncertain because it has been transported around from island to island during the various migrations of the Pacific islanders.

Euphorbiaceae is a large family that includes 310-320 genera and 7500 species (Walters and Keil, 1996). Two centers of distribution for this family are tropical America and tropical Africa. The family has an extremely variable life span and habits are found as annual and perennial herbs, vines, succulents, shrubs and tall trees. Members of the Euphorbiaceæ are found in many habitats, from deserts to rain forests. Euphorbiaceae family has genera used as unconventional foods In Mexico, 826 species under Euphorbiaceae family are found with 50 genera including those introduced from elsewhere and cultivated. A subfamily with a larger number of genera is Acalyphoieae (16), while Euphorbioideae has more species (306), and Crotonoideae has more specific endemism (Martinez-Gordillo et al, 2002). Some of these plants are used in traditional medicine, in oil industry, as ornamental plants, and as food additive. A few examples of its uses include edible wax from Euphorbia antisyphilitica (candelilla) that coats fruits and vegetables to retard water evaporation. Jatropha dioica is a small shrub that is used in traditional medicine and Euphorbia pulcherrima (Poisenetta) an ornamental plant.

Commercial capers are the immature flower buds, which have been pickled in vinegar or preserved in granular salt; they are used raw or cooked as condiment in different recipes. Semi- mature fruits (caper berries) and young shoots with small leaves may also be use as a condiment in salads or as an appetizer before meal. Capers and caper plants, wild and/or cultivated, are used in almost all the area of Capparis subgenus Capparis, extending from West Africa to the Norfolk islands in the Pacific, and most of the species are of alimentary or medicinal interest (Rivera, Inocencio, Obón & Alcaraz, 2003). Capparis is a term coined by Theophrastus (4th cent. BC) and validated by Dioscorides (1st cent. AD) (Êáððáñéò), although it seems not to have come into wide use until the spread of the Arab world.   Caper and its relatives in several European languages can be traced back to Classical Latin Capparis “caper”. Latin Capparis, in turn, was loaned from Greek kapparis [êáððáñéò], whose origin (as that of the plant) is unknown but probably West or Central Asia. Another theory links kapparis to the name of the island Cyprus (Kypros [Êáðñïò]), where capers grow abundantly.

Kair (Capparis decidua (Forsk.) Edgew, is an under-exploited, drought hardy, multipurpose, perennial, woody shrub or small tree found in hot arid regions of many regions of the world. It is a many branched, leafless and spinose plant capable of growing in different habitats. Due to its xerophytic adaptive nature, the plant grows successfully under harsh climatic conditions of arid regions. The immature fruits are used as fresh vegetables and also in the preparation of pickles. Dehydrated fruits are used in off season as vegetables either alone or in combination with other dried vegetables. Dehydrated kair is one of the important ingredients of ‘panchkuta’, a dehydrated mixture of sangri, kair, kachri, kumat and kamal kakri. However, mature unripe fruits without processing are unpalatable as these contain high concentration of glucosinolates. Ripe fruits are sweet and acrid and enjoyed by children in natives.

Although the thriving dye industry in many countries throughout the world is now predominantly serviced by synthetic dyes, the knowledge of the plants used to produce natural dyes still survives among some dyers, who use plant dyes to some extent. Nonetheless this indigenous knowledge is rapidly being lost as increasingly less information is being passed on to succeeding generations. Thus several countries are taking steps to revitalize this natural dyes industry. In this article the history of natural dye plants is presented; several plants from selected countries, which are used in the dyeing process are documented, together with some general methods of dye production and fabric dyeing; pattern production and the chemical constituents of some of these plants. The potential for the sustainable utilization of this important ecofriendly renewable natural resource is discussed.

The use of natural dyes lost ground together with the old traditional dye methods towards the end of 19th century soon after the synthetic dyes came to the market (Gilbert and Cooke 2001). Only artisans, craftsmen, and green–minded companies continued dyeing with natural dyes (Hartl 1997). The first recorded synthetic dye is picric acid produced in 1770’s from the interaction of indigo and nitric acid. The synthetic dye industry is considered to have started when Perkins synthesised mauveine (mauve) in 1856 in the UK (Hancock 1997). With the passage of time, it was observed that synthetic dyes used by the textile industry are a source of environmental pollution (Seker et al. 2007) and they produce allergic, carcinogenic and detrimental effects on the health of humans (Singh and Singh 2002, Mahanta and Tiwari 2005). The synthetic dyes were preferred by the industry because of their simpilicity in the use and all colors could be produced easily, but the problem was the waste deposition which is a major cause of environmental pollution. The solvents used during dying reduce the problem to some extent but the waste water purification needs extra effort and money (Shreve and Brink 1985). As against this, the natural dyes are not only harmless to the humans but also cause far less environmental pollution, and have distinctive washing and sunlight fade–resistant characteristics (Mert et al. 1992, Angelini et al. 1997, Kim and Park 2006). For this purpose, the textile industries have started rethinking about the natural dyes and are trying to find sustainable as well as non–toxic alternatives to synthetic dyes for a growing textile market.

Social civilization of the Neolithic settlements of primitive human communities contributes substantial initiation of cultivation and an approach towards conservation of useful plant species for sustainable food habits. Several archaeological attestations confirm that Homo sapiens at the end of the Paleolithic period had knowledge on many useful plants derived from food gathering techniques. Growth of human populations beyond the size that hardly supports hunting and gathering for food materials may perhaps be the probable reason that forced the Neolithic primitive nomadic communities for settlement and emergence of crude forms of cultivation.

Bael is one of the oldest and useful trees of India. The bael fruit, (Aegle marmelos Correa) is also called Bengal quince (John and Stevenson, 1979), Indian quince, golden apple, holy fruit, stone apple, bel, belwa, sriphal and maredoo in India. Among the indigenous fruits of India, Bael occupies an important place. All the parts of bael tree have their own importance. It is a medicinally and economically important fruit crop with immense potential for extending its cultivation in semi-arid degraded land. Mention of bael cultivation in Indian literature dates back to 800 B.C.  Bael fruit is available in almost all states of India but most abundantly available in Uttar Pradesh, West Bengal, Bihar and Orissa. The Bael fruit is one of the most nutritious fruits. It contains 61.5 g water, 1.8 g protein, 0.39 g fat, 1.7 g mineral, 31.8 g carbohydrate, 55 mg carotene, 0.13 mg thiamin, 1.19 mg riboflavin, 1.1 mg niacin and 8 mg vitamin C / 100 gm of edible portion (Gopalan et al., 1971). It contains the highest riboflavin content among fruits. Marmelosin is, most probably, the therapeutically active principle of bael fruit. It is isolated as a colorless crystaline compound (Dixit and Dutt., 1932).The astringent taste of bael fruit is due to phenolic compounds. The medicinal properties of bael have been dealt with in Charaka Samhita (Aiyar, 1956). Bael fruit has curative, pesticidal and nutritive properties. The leaves of bael are used for worship of Lord Shiva. Green bael fruits are used for preparing Murabba (preserve) generally taken for stomach ailments. Bael fruits have an immense potential for processing into products like squash, jam, toffee, candy and syrups for internal and foreign market.

Carambola (Averrhoa carambola) is a fruit of warm tropical and sub- tropical areas of the world. The fruit is oblong with three to six longitudinal ribs, resulting in a star shaped cross section when cut. Usually they have five ribs which give rise to common name of ‘five corners’ or ‘star fruit’. The tree is medium-sized, attractive and evergreen growing to about 10m. The fruit has emerged as an interesting addition to the table fruit, not only as fresh fruit, but also for its juice, decorative uses and sherbet qualities.

Tropical plum (Spondias mombin) also known as yellow mombin, hog plum, and java plum, is a deciduous fruit species widely spread in the tropics. This species is evaluated for its fruit as an unconventional source of vitamins A and C, which are used for making juices, ice creams and jellies. This plant also has medical importance.   It is a graceful tree of the family Anacardiaceae, a native of tropical America. It was introduced into India for edible fruit and also to serve as fencing. The fruit flesh (48% on  weight of fruit) contains: total solids 11.47%, protein 1.38%, fat 0.57%, acids (astartaric) 1.50%, reducing sugars 9.41%, sucrose nil, fibre 1.17%, and mineral matter 0.66%. The seeds are eaten when tender. The fruit is a good source of minerals and vitamin B1 and C.

The circumstances concerning the diffusion of  main cultivated citrus from their places of origin in Asia are studied here, showing that the citron (Citrus medica L.) was the only one known in Ancient times in Europe, while the lemon (C. limon [L.] Osbeck), lime (C. aurantiifolia [Christm.] Swingle), pomelo (C. maxima [Burm.] Merr.) and sour orange (C. × aurantium L.) were introduced to Europe by the Muslims via the Iberian Peninsula and Sicily, and that the grapefruit (C. × aurantium L. [C. paradisi Macfad.]), mandarin (C. reticulata Blanco) and sweet orange (C. × aurantium L.) arrived to the West between the fifteenth and nineteenth centuries as a result of the trade with the British and Portuguese colonies.

The common fig, (Ficus carica L.) is a fruit of warm temperate zone. It is one of the oldest fruits known to man and is mentioned by well known Greek writers Homer and Plato. Mention about this fruit is in the earliest chapter of Bible. Figs belong to family Moraceae, which include many tropical fruits and ornamental species. The fruit is known botanically as ‘syconium’ in which the flowers are borne on the inner walls of a hollow receptacle. It is one of the most salt and drought tolerant amongst fruit trees. Fig is a moderate sized deciduous tree in subtropics but performs as evergreen in tropics. Branches are irregular, shoots develop at base of trunk, leaves are very broad, ovate and long stalked. Fruits mostly long stalked, pear shaped with a velvety or glabrous skin, yellow, brown, purplish or black in colour. 

Guava is one of the most common fruits grown widely throughout the tropical and subtropical regions of the world. Guava is hardy in nature, prolific bearing and highly remunerative even without much care (Mitra and Bose, 1990). Because of its excellent adaptability and exceptional performance in the tropics, it is regarded as the ‘apple of tropics’. In India, guava is the fifth most important fruit crop in terms of area and production. It is cultivated over 1.51 lakh ha area with a total production of 18.0 lakh tones (Chadha, 2001). It is rich in pectin and used for jelly making. It is useful as table fruit and also for processing purpose. It is known by different names viz., madhuri (Assamese), peyara (Bengali), phanas (Gujrati), amrood (Hindi), sebe (Kannad), soh-priya (Khasi-Meghalaya), komperam (Garo-Meghalaya), pera (Malayalam), peru (Marathi), pijuli (Oriya), amrud (Punjabi), koyya (Tamil) and jama (Telugu).

Star gooseberry also known as Otaheite gooseberry   (Phyllanthus acidus Skeels) is an important underexploited fruit of family Euphorbiaceae. Phyllanthus distichus Muell. Arg., Phyllanthus acidissimus (Blanco) Muell. Arg., Cicca acida Merr., Cicca disticha L. are the synonyms of star gooseberry. Food value of star gooseberry / 100g of edible portion is given below.

Hog-plum also known as wild mango (Spondias pinnata), is native to tropical Asia. A small, aromatic deciduous tree, up to 27m height and 2.5m in girth, with a clear bole of 16m, is found wild or cultivated almost throughout India, ascending up to an altitude of 1500m in the Himalayas; also found in the Andamans. Bark thick, aromatic, smooth, grey; leaves imparipinnate, 20-60cm long, leaflets 5-11, 22-28cm long, ovate-oblong, elliptic or elliptic-oblong, more or less oblique with mango-like smell; flowers whitish or greenish white, polygamous, in large, terminal panicles; fruits in terminal clusters of 10-15, drupes yellow-green or rich olive-green, mottled with yellow and black, smooth, ovoid, 4-7cm long; seeds 1-3, one being perfect, oblong-elliptic. Fruit is extremely sour, even when completely ripe.

The extensive use of improved types of vegetable crops has led to a  situation that the indigenous types are virtually disappearing from ecosystems creating a vacuum in crop biodiversity. Biodiversity of genes, species, ecosystems and habitats will remain under threat. Habitats will be decreased and fragmented, endangering many indigenous, rare, endemic and specialist species populations and ecosystem functions, although generalist and invasive species will continue to spread. Therefore, loss of biodiversity can be considered at three scales: genes, species or populations and habitats or ecosystems. Maintaining thriving natural systems is essential not only for economic or ethical reasons, but also for ecological, social, recreational, educational and aesthetic reasons (Gomez, 1996). Most of these are easy to grow, resistant to pests and diseases, hardy and acceptable to local taste. They are rich in carbohydrate, proteins, fats, vitamins and minerals; hence the diets could be diversified to meet the nutritional requirements of the people in the country. The lack of micronutrients, including certain vitamins, minerals and other components needed for a healthy diet, is a pervasive and growing threat throughout the world.

Introduction Tripura is situated between 22º56 ‘to 24º32’ N latitude and 91º10’ to 92º21’ E latitude with tropic of cancer passing through it. The total geographical area of state is about 10,491 Sq.Km of which 58.90 percent area is under forest cover. More than 75 percent of the population either directly or indirectly depends on agriculture. The small and marginal farmers contribute about 90 per cent of total farming community and the average size of land holding is 0.97 ha (1990-91) in comparison to 1.25 ha (1976-77), which is the lowest among the seven other North Eastern states.   The state weather is characterized by warm and humid subtropical climate with three distinct seasons viz., summer, monsoon and winter with three different cropping seasons like khariff, rabi, summer and jhum cultivation in forest during pre monsoon and late monsoon periods. This state has many rivers out of which the important ones are Juri, Deo, Manu, Dalai, Thowai, Haora, Mahari, Burigang and Gomati which are mainly seasonal. Tripura receives an average rainfall of 2065 mm.The monsoon breaks in May – June and continues for about 4.5-5.0 months.

Promotion of perennial crops is a good alternative for food security since they offer more consistant, year-round production without any break. Agathi and Chekkurmanis are the two nutritive perennial greens that can be easily grown in hot and humid tropical climate.

The effect of oil sludge on the growth and performance of Celosia argentea (L.) were evaluated using four levels of pollution viz: 0%; 0.25%, 0.5% and 0.75% of the 6kg soil and three levels of N.P.K. fertilizer (20:10:10) viz: low level (0.005 kg), normal level (0.01 kg) and high level (0.015kg). These treatments were imposed after the soil analysis were carried out on the site.  The results obtained show that pollution has a significant effect (P < 0.05) on the growth and performance of Celosia argentea, despite the different levels of fertilizer application with second level of pollution (0.25%) being the critical point. Thus, pollution retards the growth of this crop drastically beyond the critical level with Celosia argentea showing more tolerance to pollution at the post-application treatment than the pre-application treatment. It is therefore suggested that land users should not embark on cultivating land that has an oil sludge pollution level beyond 0.25% of soil.

My first experience with Colocasia gigantea (Blume) Hook. f. (Araceae) was one of personal cultural food use. I recently came to Hawai‘i for my Ph.D. studies, and although I am Vietnamese, it was in Hawai‘i that I began experiencing many Vietnamese foods I never knew as a child growing up in the northeastern U.S. I thank the Vietnamese immigrants in Hawai‘i that became my aunties and uncles from whom I learned a great deal about my roots and the food of Vietnam. I listened to their stories and teachings while we ate together at holiday and community events, reflecting on my childhood, and considering the effects of globalization on the movement of people and plants, I have come to understand the extraordinary significance of that seemingly mundane first experience of eating C. gigantea. In this paper, I describe the botany, ethnobotany,  including a case study of C. gigantea usage in Hawai‘i and the implications for biocultural diversity, and examples for increased utilization of C. gigantea.

The Begonia family has a tropical and subtropical distribution in America, Asia and Africa. With approximately 100 species and 10,000 cultivated hybrids, they are very important as ornamental plants.A few reports describe Begonia as edible; the highest number of these species is found in America, some in Asia, and we have only one report of an edible Begonia in Africa. The Begonia family has a tropical and subtropical distribution in America, Asia and Africa. There are approximately 600 species in America, and the same number in Asia. Africa, including Madagascar and the Mascarenes, has 158 reported species, one third of which are endemic to Madagascar and associated Isles (Mascarenes, Seychelles and Comoros). Only ones species, B. grandis Dryander, is widely distributed in temperate regions, extending northwards near Beijing (Forrest & Hollingsworth, 2003; Plana, 2003).

Kangkong also known as water spinach, water convolvulus and swamp cabbage is an important leaf vegetable in South East Asia including Taiwan and Malaysia. It is a semi aquatic herbaceous plant having trailing or floating habit; sometimes it is biennial or perennial. Normally the main shoot of this plant trails horizontally and lateral shoots bear leaves and flowers and trail like the main shoot. Stem is hollow and leaves are arranged alternate. The succulent foliage is light green and leaves are elliptic or ovate oblong and cordate at the base. Flowers are 2.5 to 5 cm long, white or pale purple with dark purple eye, solitary or in five flowered cyme. Fruit is a capsule, ovoid and smooth with 2 to 4 seeds. This crop is ideally suited to areas where water stagnation is a problem and is found trailing on moist soil or mud along margins of stagnant ponds, streams, marshes and wet rice fields. It is sometimes found floating on water surface. At every node, it produces a number of adventitious roots.

Tree tomato belongs to the family solanaceae, genus Cyphomandra and species betacea. The Cyphomandra genus is made up of about 30 species. Shaw (1996) has reported that Cyphomandra genus consists of 35 species confined to the New World tropics. They were earlier described under the genus Solanum. They can be separated from Solanum  by several characters, the most important being anther characters. In Cyphomandra in the anther the connective is thickened and expanded dorsally. As a result, it is clearly differentiated from the anther thecae, which is thin walled and papillose. Economically important plant in this genus is Cyphomandra betacea. Other important related species are Cyphomandra casana (Casana), C. craccifolia (Mountain tomato) and C. fragrans (Guava tamarillo). It has got distant affinity with Lycopersicon esculentum (Tomato), Physalis ixocarpa (Tomatillo), P. peruviana (Cape gooseberry), Solanum muricatum (Pepino Dulce) and S. sessiliflorum (Cocona).

Palms are monocot species, belonging to the family Palmae (Arecaceae). They are perennial and distinguished by having woody stems. Coconut, Arecanut and Oil palm are the major crops coming under this group. Palmyra is a naturally occurring palm in many parts of Tamil Nadu, Andhra Pradesh, Karnataka, Kerala, Orissa, Bihar and West Bengal States. Palmyrah is utilized by the locals for tapping inflorescence sap and for fruit. Palms of India are represented by 20 genera and about 96 species among which 24 species belonging to nine genera are endemic to India. The largest genus, Calamus with 44 species is followed by Phoenix seven, Pinanga five and the rest with less than five species each. The genera Borassus, Salaca, Livistona, Nypa, Hyphaene and Ptychoraphis are represented by a single species each. In addition, C. nucifera and A. catechu are extensively cultivated as plantation crops. They have almost naturalized in parts of Kerala and Andaman Nicobar Islands. Except P. sylvestris, C. urens and B. flabellifer which are widespread in peninsular India, the rest are of restricted distribution in specialized eco-geographical regions of the country. The forests of Andaman–Nicobar islands (13 genera, 24 species), northeastern and eastern Himalayan region (12 genera, 36 species) and the Western Ghats (7 genera, 30 species) are major centres of palm concentration. Nypa fruticans and Phoenix paludosa are fringe mangrove species occurring in salt marshes of Sundar-bans and Andaman–Nicobar islands. P. paludosa is also found in Orissa.

Index A A. Tricolor 327 Aattunjaval 179 Abrus precatorius 88 Acacia 88, 110 Acalyphoieae 7 Acanthaceae 329 Adenia hondalum 156 Adriatic 267, 268, 269, 274 Aegle marmelos 152, 155, 160, 201, 203, 208, 213, 216, 220, 221, 222 Aeglefolia 202 Aeglemarmelos 202 Agasthyamalai 154 Agathi 359, 360, 361, 362, 363 Aghori 169 Agroclimatology 371 Agrotechniques 73, 77, 294 Aicrp Palms 420, 429 Air-layering 159, 160, 161, 163, 167, 168,  169, 297, 308, 312 Alangium salvifolium 155, 162, 187