TF,,,, EDIBLE LEAVES OF THE TROPICS 2nd Edition Franklin W. Martin and Ruth M. Rubert6 Mayagiiez Institute of Tropical Agriculture C) Mayagiiez, Puerto Rico Agricultural Research Service, Southern Region U.S. Department of Agriculture Published by Agricultural Research, Southern Region, Science and Education Administration, U.S. Department of Agriculture Printed by Antillian College -tess Mayagiiez, Puerto Rico 1979 111 FOREWORD Under tropical conditions, green leaves are everywhere, providing that soil and water conditions are not limiting. These leaves can be considered as highly organized factories that convert local crude materials, carbon dioxide, water, and minerals, to food. Green plants are tile beginning of tile food chain, and on them depends the life of other terrestrial organisms. Man, as an example of an advanced or predator species of the food chain, would be sorely pressed in tile absence of green leaves. Green leaves in the tropics serve as direct food sources to ,nan under the most civilized Jircunlstailces. The important species are grown and pre­ served on both home and commercial scales. In primitive areas green leaves from wild plants are used as regllar U iinportant items of the diet. In times of emergency green leaves provide nuitritious and ieadily available sources of food. Yet, these usages harl V touch on the potentials that exist in most en­ vironments. The green factories are underutilized and r 2glected, or depre­ cia ted and destroyed. Amovg the reasons for such neglect are ignorance and prejudice. Both cciditions are Ilard to c11rc. BCcause lmany people live in cities, they have not had tile opp )rtullitV to try the wild herbs and other green leaves around them. The special knowledge ofteii in the hands of ;afcw wise members of the tribe or society is nit regularly passed down to the younger generations. Furthermore, as de pendeiice on imarket products increases, wild or weedy plants become despised. In the interests of marketing, only I limited iumiibet of species are propagated on a scale s, Ifficieltly grand to permit econinii of handling operatils. As pressures on the land increase, there is a growing dan­ ger of exterimination of' minor species. Furthermore, experimentation ceases. The grand total of liuati knowledge can then decrease. Withliout doubt, solme local usages have already disappeared, and not even written records are left. Lost in this historical pr i ess are the tecliiiiques for discovering new vegetables. Surely usages were revealed only through experimentation. There must always have been those who looked for, cooked, and ate new leaves for the excitement of discovery. Ill the process. the poisonous species were even­ tually discovered, the irritating types avoided, and the obnoxious rejected. In isolated areas, interest may be maintained or restiieIUlated. During tile Nigerian civil war, for e.amlple, starvatior stimulated new experimentation in the bush, the results (f which will probably be lost again rapidly. Nevertheless, a new breed of' explorers has arisen. those who are dis­ enchanted with the bland products of tile supermarkets, those who still feel tile primordial urge to plant, those whose tastes are adventurous. There are also those whose pocketbooks are thin who cail benefit from green leaves easily grown at home. Finally, there ire tile few who recognize that tile vege­ tables we emphasize now are but a part of a larger, and mostly still available heritage, a heritage whose potentials have still not been fully realized. It is to tile lovers of edible green leaves that we dedicate this book. V TABLE OF CONTENTS Page Forew ard .......................................... V List of illustrations ................................... 2 I Introduction .......................................... 5 11 The Principal Edibie Green Leaf Herbs of the Tropics ......... .17 IIl Some Fruits, Vegetables, and Ornamental Plants that also bear Edible Leaves ............................ 43 IV Common Weeds with Edible Green Leaves................ .... 61 V Tropical Trees with Edible Green Leaves. ................. ... 81 VI Tropical Leaves as Spices and Teas ......................... 97 VII Temperate Zone Green Leaves in the Tropics .............. .. 109 VIII Lettuce in the Tropics ................................. 123 IX Tropical Leaves that are Poisonous ........................ 133 X Culture and care of Green-Leaved Vegetables .............. .. 151 Selected references concerning edible and poisonous leaves ..... .165 A list of tropical plants with edible leaves .................. 171 Index to species mentioned in the text ..................... 227 - 1­ Illustrations Figure Page 1. A plant of the queen of the spinaches, Xallthosorna brasiliense ................................... Cover 2. A broad-leafed variety of edible amaranth .................... 1.8 3. Leaves of Xartlosoma (left) and Colocasia (right) .......... ... 22 4. Young plant of fiasella rubra, Ceylon spinach .............. ... 26 5. Ipomoea aquatica, Kangkong at tile proper stage for use as a pot herb ..................................... 29 6. The leaves of' Telfdria occide rtalis at about the stage they are marketed in West Africa ........................ 32 7. Recently matured leaves of Amrilot escrlenfta, cassava, at the stage for cooking .............................. 34 8. Leaves, flowers, and fruit of San ropns ,midroyms .......... ... 36 9. Mature plant of Taflimn trimrrlr..........................t 40 10. The delicate edible inner leaves of'corn ...................... 44 11. The sulfur colored leaves of fibiscus manihot ............... 47 12. Cassia alata, ringworm senna, a medicinal and edible leaf...... .. 50 13. Leaves of Esphorbia pmIchrrrimr the poinsettia, a debatable species ................................... 51 14. Young plaints from cuttings ofCtnidoscolus chaya?n eusis ...... 53 15. Leaves of,3 racardi m occid,'talle, the c isliew ............. ... 54 16. The edible leaves of the dtrrian, I)imro ziethimis ............ .... 56 17. A branch ,f tamarind, Ta,;arimdurs inrdica, with edible tips and young fruits ................................. 58 18. Young leaves of the mulberry, ,orr,s ala.................... 59 19. A clump of the edible weed, Jsticiainrsrnlaris .............. ... 63 20. Leaves and flowers of 'Irmbergiaalata, susana ............. ... 64 -2­ Figure Page 21. Bidens ;,ilosa, Spanish needles, is a widely distributed edible weed of the tropics ............................ 66 22. Foliage and flower of the beach morning glory, lpolno'apc's-C(pr,( . ...... ............................ 68 23. Leaves and mature fruit of the wild balsam pear, Moinordicacharantia ................................. 70 24. leperomtia jellucida, a common edible weed of greenhouses ........................................ 72 25. An edible Portulaca from the fields of Puerto Rico .......... .. 75 26. Edible leaves and ripe pods oflErythrinaberteroana, dwarf bucare ...................................... 83 27. The leaves of' mother-of-cacao, (Gliricidium sepitim .............. 84 28. The pinnate leaves of the weedy tree Leucaepia lecoceplala ...................................... 86 29. The flower and fruit of Admsouia d(iitata,baobab .......... .. 90 30. Leaves and fruit of Alorimda citrifolia...................... 93 31. Mature trees of Aloriga oleifera, the horseradish tree ........ .. 94 32. Culantro, the false coriander of Puerto Rico, used for its spicy leaves .................................... 100 33. The oregano of Puerto Rico, Lippia helleri ................. 103 34. Albahaca or basil, as grown for its leaves in Pulerto Rico ....... 104 35. Cabbage in a garden clearing in the Caribbean ............... 112 36. A hillside planting of cabbage, established and cultivated by hand, in the n1ountains of Puerto Rico ....... .113 37. Harvest time, and the most reliable way of getting cabbages out of the field ............................ 115 38. A sugar beet field in Puerto Rico, with laige edible leaves ...... .120 39. A leaf-lettuce, Black Leaved Simpson, that does well in the tropics .................................. 124 -3 ­ Figure Page 40. Gardening for lettuce on a small commercial farm of Puerto Rico .................................. 126 41. Head lettuce grown at a mediul elevation in the trO)iCS, siniig itetIIi-Solid had. ...................... 129 42. Lettuce flowering. ..................................... 131 '13. ()rtiga, I rcra baccitera, I stinging nettle of the Caribbean ...... 135 44. The castor bean. pocisonous plant, the leaves of'which are processed for eatin ......... .......................... 139 t 45. Neri m oea(pietr. one of the most .danLgcrous of garden shrubs .......................................... 141 46. Leaf and flower of Crvp Ict,stciaumliflo.1 1. erroneously called the purple allamamda .................. 143 4 7. .lh'rites /ordii. tung, ihe source of oil amd poison ts leave ................................... 144 48. Crotalaria rethsa L..:.is c(ohrful flowers and poisonous Iaves.. .................................. 147 49. Litaoa caMoilri with its colorful f ,wers and fruits .......... 148 50. A Saran Clohli shelter used '0 mdIC light intensity andlc liperature. .. ............................... 153 51. A 4ax.li hedge which rTedics wind ti Ih.r the glass roof ....... .. 154 52. A field illuiinated whh light at iiigit Io avoid short div effects .................................... 155 53. Plants showing symiptomiiis of nitrogen deficiency (right) compared to healthy plants of