Weeds As a Source for Human Consumption. a Comparison Between Tropical � �Ajjd Temperatelatinamerica

Rev. Biol. Trop., 47(3): 329-338, 1999 www.ucr.ac.cr www.ots.ac.cr www.ots.duke.edu

Weeds as a source for human consumption. A comparison between tropical � �aJjd temperateLatinAmerica

Martha Díaz-Betancourtl, Luciana Ghennandi2, Ana Ladi02, Ismael R. López-Moreno1, Estela Raffaele2 and Eduardo H. Rapoport2,3 1 Instituto de Ecología, Ap. Postal 63, Xalapa 91000, Veracruz, México. [email protected] 2 Universidad Nacional del Comahue, Departamento de Ecología, 8400 Bariloche, Argentina and CONICET [email protected] 3 The sequence of authors was alphabetically ordered.

Received 16-IX-1998. Corrected 15-1I-1999. Accepted 22-II-1999.

Abstract: Weeds abound in urban and agricultura! environments. Depending on region and site, up to 66% of weed species are edible, and may constitute an additional food source for humans. Based on 400 samples, 1/4 m2 each, collected in tropical areas (e.g., roadsides, urban vacant lots, streets, sugar cane and coffee plantations in Coatepec, Mexico), average figures of edible fresh biomass vary between 1277 and 3582 kglha. A similar sur vey performedin a temperate area (739 samples in Bariloche,Argentina) showed mean values between 287 and 2939 kglha A total of 43 species were sampled in Coatepec and 32 species in Bariloche. The general means were 2.1 and 1.3 tonslha, respectively. At a greater geographic scale, a comparison between Mexican and Argentine weeds shows that, proportionately, the food parts vary a little between regions. In general, from higher to lower, the order of uses goes from leaves, seeds, roots, fruits, herbals, flowers and condiments. Edible roots (including bulbs and rhizomes) appear to be more COmInon among perennials thanamong annuals.

Key words: Argentina, Bariloche, Coatepec, edible weeds, food plants, gathering, Mexico, Patagonia, urban flora.

Although plants have sustained the hunt of the old tradition is still maintained in sorne ing and gathering peoples since the Latin American and eastem Asian countries. In Paleolithic, the prevailing knowledge about Mexico, more than 20 "weeds" are also culti edible species began to be lost since the inven vated (Linares and Aguirre 1992). For tion of agriculture in the Neolithic. Two well instance, in Korean local markets 112 wild preserved murnmies found in Denmark, pro plants are sold at prices higher than those of vided interesting infonnation on food habits cultivated species. Moreover, eleven species during the Iron Age. Their last meals con (sorne of them "weeds") are exported to the tained 66 different plant taxa (Godwin 1960; U.S.A. and used to prepare Korean and King 1966), i.e., a diet much more diversified Chinese typical dishes (pemberton and Lee than that of modem mano According to FAO's 1996). Sirnilarly, Moroccan weeds are export Production Yearbooks, developed countries, ed with the same purpose to the U.S.A., Spain, and especially urban populations, began to Italy and Greece (Tanji and Nassif 1995). depend almost entirely on the extensive The use of edible wild plants and weeds and intensive agricultural production consisting in has been considered by several authors (Harris merely a little more than 100 food plants. Part 1969, Kunkel 1984, Facciola 1990, Zudo and 330 REVISTA DE BIOLOGÍA TROPICAL

Brandao 1990, Duke 1992, Linares and dehydration at 60-80 o C (Rapoport et al. 1995). Aguirre, eds. 1992, and references there). Additionally, in some cases, the yields were Some of these books only provide extensive assessed in terms of biomass collected per lists of species, with indications of their edible minute of harvesting. This survey was per parts, while others add descriptions and illus formed in order to evaluate whether there is auy trations of the species. Clarke (1977), Michael profit in gathering a given species in sites (1980), and Linares and Aguirre (1992) where it is abundant. In way, we were in this inelude numerous recipes. Edíble weeds, how the position of a person searching for food. The ever, are scarcely used in many countries, and analysis of the proportions of edible parts weed gathering is more of a weekend hobby (roots, leaves, fruits, seeds) of all Mexican aud than a regular source of food supply. Argentine weed species was obtained from To our knowledge, no attempts have been Kunkel's (1984) list, and from our own records. made to assess quantitatively the potential Comparisons of fl'esh edible weights among amount of food provided by common weeds habitats were made by means of Kruskal-Wallis aud escapes. tests. The comparison of total fresh weights Our interest was to evaluate the available between Mexico aud Argentina was made by biomass of human food provided by weeds in means of a Maun-Whitney test. In the case of urban, periurban aud field habítats in the north significant differences, the Student-Newman ernand southernNeotropical regíon. We tried Keuls' test of multiple comparisons was to compare two samples obtained in different applied. The detailed statistical analysis of data c1imatic regions, Le., tropical (Coatepec, is repOlted elsewhere (Ladio et al. 1998). Mexico) and temperate to cold-temperate The main roads sampled Bariloche were in (Bariloche, Argentina) areas. roads No. 258 (Bariloche-El Bolsón), No. 237 (Bariloche-Alicura aud Bariloche-Airport) and No. 237 (Bariloche-Llao Llao). In Coatepec,the MATERlALS AND METHODS road sampled was Carretera Briones.

The environments selected were aban doned fields, main (paved) roads, secondary CLIMATE roads (suburban dirt roads), pathways, vacant urban and suburban lots. Sugar cane fields, mil Comparative data on climates appear in pas, coffee plantations (only Coatepec), aud Table 1. orchards (only Bariloche) were also consid ered. In these cases, we gathered and weighed all the edible parts of species appearing in 0.25 RESULTS m2 quadrats (50 x 50 wooden frames). Along roadsides (haphazardly selected), we sampled The majority of the sampled species at repeated 1 km distances, by laying ten appear in Kunkel's (1984) list of food pIants, quadrats regular1y at 2 m distance each, paral to which we added Osmorhiza chilensis, from lel to the pavement. Urban vacant lots aud Argentina, and Drymaria gracilis, Galinsoga fields were raudomly sampled. The frames quadriradiata, Hydrocotyle bonaríensis, were laid along a random walk using a stop Hydrocotyle mexicana, Margaranthus sul watch to select compass direction and number phureus, Oxalis latifofia, Sida glabra, S. spin of steps. The coIlected plants of each sample osa, and Tripogandra, serrulata from Mexico. were kept in plastic bags and transported to the These plauts are cornmonly consumed by peo laboratory, separated by species and their edi pIe and were repeatedly tasted by uso ble portions were weighed with 0.01 g preci In total, 43 species were recorded in sion. Water content was calculated aftel' 72 Coatepec aud 32 species the Bariloche samples hr in et al: Weedsas a source for human consumption 33 1 DÍAZ

TABLE 1

Comparative characteristics 01 both areas

Coatepec Bariloche

Altitude 1,252 m 75 0 m 19°27 °N 41°08' S LongitudeLatítude 96° 57 " W 71 °08-71°36 'W Mean annual precipitation 2250 mm* 100 0mm** Mean annual temperature -I8�8°C . 8-.4 oC Coldest month mean temp. 15 .2 °(Jan.) 2.3°(July) Hottest month mean temp. 21.4 oC (May & June) 14 .5 oC Extreme temperature 3.9 to 33.5 oC -18 to 35(Feb.).5 oC Prevailing winds N & NW (winter), E, S & SE W (spring, summer & fall) Climate A C (fm) w"a(i')g GCs lk (Meditenanean regime) Population 40,000 100 ,000 Source Gómez and Soto 1990 RudloíI 1981 ; Grígera et al. 1989; UNC 1983

'" Raíns all year round, although more intense in summer. ** Rains and snow, with maximum precipitation in winter.Pre¡;ipitation varíes from 800 mm in the eastern to 1.600 mm/yr in the western parts of the city.

(Tables and represent, however, a Coatepecan yields(2.1 tons, on average, per 2 3). They small fraction of the richness ateas. hectare) were apparently higher than the real in both More than the weeds listed Bmilochean yields tons per hectate).. The 24% of 700 in (1. 3 anonymous (1991) are edible. the extreme was on a Mexico by Of maxill1um yield recorded exotic weeds. recorded northwestern road between Coatepec and 320 in main Xalapa and based on Patagonia (Rapoport Brión 1991), 90 (10,158.0 kg/ha) 10 samples taleenin species are edible.The Catalogue on a vacant 10t in (28%) of January 1996, and Bariloche MexicanWeeds (anonylllous includes kg/ha) based on samples 1991) 168 (7,542.9 7 taken in species which perennial December 1996.When<:;omparingequivalent edible of 36.3% are and annual andJor Similarly, Coatepecan. Barilochean environments 63.7% biennial. in and by Argentina, proportions are means of a Mann-Whitney test, the differences the 35.0% and respectively, of edible wel'e not significant 65,0%, from a total 160 (P>O.05). However, the weeds are Marzocca et differences· in values among·total that mentioned in al. · the median Perennials show asignificantly yields per hectare of Mexico Argentina (1976). higher and edible roots (including tubers 01' wel'e significant = P = proportion of (U 880; 0.03) rhizomes) herbals than among the The and annual Gatheringharvest. Species' yields: biennial species = correspond to fresh weights (P 0.027 and 0.021,respec following data of tively; In contrast, annual-biennials the edible parts obtained per spedes in a Table 4). given show a greater edible leaves period time. Sites were selected theirspe proportion of and of fOl' seeds perennials = abundances, from point than (P 0.008 and 0.012, dal the oí view of a respectively) as showed means a x con person searching for food. The process ofgath by of 2 2 tingency tableo eririg in Mexico took minutes sam 15 fol' each Because the number (five samples per species) mean Yields per hectare: pIe andthe val': of surveyed the number of samples ues are presented per minute (Table sites and 6). pe}'" site were numerous, we made a tentative InBariloche, three species were eval only assessment.ofthe amount offood available per uated. Taraxacumofficinale (8 sampling (i) hectal'e Inthecase of plantations and sites, minutes total time). (Table 5). 21 gathering cultivated plants were not Dependil1g on its abundances, yields Ol'chards, included. varied 33 2 REVISTA DE BIOLOGÍA TROPICAL

TABLE2

Coatepec, Mexico. Mean availablefood (fresh weight in grams) per 0.25 m' sample andfrequencies (number of times

each species wasfound in 100 samples); SD = standard deviation

Species Vacant lots Dirt roads & pathways Plantations Highways mean S.D. freq. mean S.D. freq. mean S.D. Freq. mean S.D. freq. weight weight weight weight

Aca/ypha wilkesiana 6.68 6.17 7 1.57 1.01 5 Amaranthus dubius 0.93 1.02 3 50.60 49.45 3 0.40 0.00 AmaranJhus hybridus 30.71 34.22 6 6.53 5.29 3 17.63 27.05 14 Amaranthus spinosus 6.10 5.32 8 47.68 0.00 Anogallis arvensis 1.23 0.90 2 0.84 0.46 4 0.27 0.00 2.35 1.62 8 Bidens odorata 9.32 10.36 30 5.20 6.26 24 5.69 5.97 14 5.86 7.57 31 Brassica rapa 3.07 2.30 4 Canna indica 16.23 0.00 Chenopadium ambrosioides 59.32 0.00 4.03 0.00 13.29 0.00 Commelina diffusa 5.77 5.44 48 5.16 6.66 43 11.19 14.76 59 45.20 56.56 59 Commelina erecta 20.90 14.25 3 12.21 6.82 5 34.67 46.29 40 Drymaria cordata 5.32 6.65 27 1.31 1.46 15 5.92 7.73 24 0.92 0.45 2 Drymaria gracilis 7.04 6.71 9 6.54 9.46 12 3.45 8.18 10 34.66 74.19 27 Galinsoga quadriradiata 6.46 7.74 20 2.95 2.83 26 7.15 10.88 17 14.20 15.61 42 Heliconia caribaea 342.81 204.63 3 Hydrocotyle bonariensis 13.95 17.83 19 1.30 1.06 13 6.57 4.16 3 Hydrocotyle mexicana 1.99 1.56 3 7.38 11.24 9 lpomoea purpurea 5.08 4.83 16 lpomoea tílliacea 5.09 4.38 7 lpomoea tri/oba 4.04 5.58 23 7.62 11.94 8 7.09 6.95 3 6.42 4.39 7 Margaranthus sulphureus 6.72 7.87 6 Oxalis corniculata 1.97 2.86 40 2.79 4.18 43 2.14 1.91 34 2.60 3.% 42 Oxalís u.tifolia 1.70 1.61 14 4.92 5.75 17 9.28 16.28 45 3.43 4.87 20 Phaseo/us vulgaris 0.70 0.26 10 Piper auritum 23.92 0.00 35.99 24.18 2 Pklntago hirtelu. 1.75 1.09 3 3.35 0.00 Pklntago klnceou.ta 158.62 0.00 Portulaca oleracea 10.38 0.00 0.61 0.26 2 Rumex obtusifolius 25.57 27.19 10 15.66 9.64 10 26.26 29.43 18 25.70 19.68 11 SidJJ acuta 2.09 1.59 2 SidJJ gklbra 1.33 0.00 Sida rlwmbifolia 5.78 7.02 49 4.37 2.19 17 3.74 4.51 14 Sida spinosa 2.87 2.26 10 14.05 12.59 8 5.41 6.87 4 Solanum nigrnm 3.75 3.62 3 9.70 0.00 1 Sonchus oleraceus 8.99 2.05 2 22.13 14.96 3 Spiklnthes americana 10.24 10.75 34 13.52 23.17 20 15.65 14.97 30 12.68 17.63 32 Tagetes micrantha 11.63 0.43 2 Taraxacum officinale 0.39 0.00 6.41 5.61 4 Tradescantia fluminensis 0.20 0.00 62.58 50.66 2 2.69 2.48 3 75.66 97.45 33 Trifolium repens 2.51 3.29 14 8.39 7.19 5 Tripogandra serruu.ta 13.27 28.39 22 10.71 13.54 11 20.88 20.08 55 Xanthosoma robustum 16.53 15.85 10 14.48 16.79 10 18.68 13.15 7 10.08 8.30 7 Youngia japonica 6.73 14.67 15 3.19 2.64 9 3.33 3.53 19 2.94 10.68 17 TÁBLE3 I ,¡¿...... ".' .. ,. 1 ,.,Bariloche, Argentina. Mean availablefood(frelhweight in afidfiel/Hencies per 0.25 m2 sample. S.D. == standard desvia'tion ' . • '. grams), .,. (f) ' ¡II Species Dirtroa. ds &Path�.aYs \Ta.cantl ots . Orchard . Aband. fields No, 191 210.I:lighwilYs��.. ,: ;si'>. 1780 65 80 m an siu,nples S.D. . f . f' mean S.D. f S.D. f me8ll. �; S.D. ' 's.b. . . �: � 0.18 Aehillea miÚefóli;;';; 0.04 0.13 .. 0.39 ". . • 2 �f� Alstroemeriaaurea * . .. 0.3. t' Blfrbf!risbuxifolia * . 0.02;:$:'i 0.06'Ü 8 1 - "" � 2.880 3.90 18 3.3 9 '4.58 23 14.36' 10.99 24 0.77 Bfa,ssi(!q,rapa 0r� C.ichori3s'ititybúsQirSiumvulgl;lré I 0.44 6 I , = Claytoñia perfoJiaia ._. ''Ji�r�''O'IJk, 0.02 1 Cytisus seópafitis - I 1 - C;henopodiúmalb/.ÜIJ' 6 4.94' 10.50 10 21.71 .14.87 36 3;34 2 Ü6. 21.00: . "'" éhrleueanihernum',,,ysqntli§iriWJi 0.06 .• 4.99 24. r 0:ü3" O�30f"" ·;3 2;65 : O;RQ 0.96 1.12 0.66 1fl '0:10 0.29 4' - Hypoe��ris"'radieata 0 "'4 Lactuea serriolá 0.21::44 0.65 1 I Malussylllestris.. 1.34 4.22 1 0.22 1 I - ·Millvasylvestrls. 0.71 1I - Medieago lupuli 0.03 0,06 1 1 - ÍÍ!J Melilotus albus Hh65 9:81 21 0.29 0.7l 2 1 - Me1:uha Spp. 2 - adorata·* 0.92 1.76 6 2.65 . 2.89 28 ��;.�.36:i! I 2. . OerWtheraOsmormza ehilensis * 0.17 1 1.54 6 I Papaver rhoeas 0.54 o.n 0.02 1 laneeolata 7:89 4.54. 67 14.61 10.70 ·0.012.28 1.54 ' 2& 0.01 0.02 1 i1 RumexPlantago aeetosella 1.60 1.24 25 3.0& 2.46 . m34 3.3:8 4.83 22 34.46 74.70 9 3 35- 2.75 19 Rumex longifolius 0.39 0.88 1 $anguisorbaminor' 0.55 . .J:24 3 Silybum marianum 0.24 0.76 F 1.21 Sonenúsasper 0:12 0.27 1 2.21 4.72 L Sonehu$ oleta¡;eús 7 Stellaria media 15.19 1 tarQJ:aeum officinale h5 3.89 8.46 11.39 4.54 30 3.69 6.87 4 14 0.10 1 2 Tragopogondubius .0 Trifoliumrépens· .. 0.050 0.140.16 0.04 1 * native spécies

V> .;� 334 REVIST A DE BIOLOGÍA TROPICAL

TABLE4 between 9.1 and 36.4 g/min, with a mean of 17.0 ± 8.8 g/mino (SD) of leaf blades without A comparison of food paT1s in Mexican (168 species) and Argentine (160 species) weeds their central nerves. (ti) Chenopodium album samples, 9 minutes gathering time). Yields (3 México Argentina were from 38.3 to 56.3 g/min, with a mean of Perennials . Annualsl Perennials Annualsl (%) Biennials (%) (%) Biennials (%) 48.0 ± 9.1 g/mino OnIy leaves and tender api cal stems were considered. (iii) Montia perfo 15.4 7.7 19.1 8.0 Roots, rbizomes liata (11 sampling sites, 40 minutes total gath Leaves, stems, 30.7 44.0 41.2 54.0 buds ering time). Yields from 31.0 to 239.6 g/min, Flowers 4.4 3.5 8.8 4.3 with a mean of 80.4 ± 65.0 g/mino Leaving 13.2 10.5 8.8 2.2 Fruits aside the figures obtained in Heliconia carib Seeds 19.8 26.6 11.8 24.8 Condiments 4.4 2.8 4.4 5.1 aea, which represents a special case for its edi HeIbals 12.1 4.9 5.9 2.2 ble roots, yields seem more productive in (tea, coffee) Bariloche than in Coatepec. Outstanding bio masses are produced by Montia perfoliata, a TABLE 5 North American invader of Patagonian urban

Assessment of available food per hectare forests.

Coatepec No. samples Meanfresh sd (0.25 m2) weight Tbe most protitable plants in Bariloche: Montia perfoliata (=Claytonia perfoliata) yield (kglha)

Plantation (coffee, This species shows c1ear capabilities to sugar cane) 100 2031.3 1285.2 recover after harvesting. Durlng the 1995 Urban & suburban vacant 10ts 100 1277.1 663.5 growth season, in Bariloche we measured the Streets and pathways 100 1453.4 1441.1 fresh biomasses of three 0.25 m2 plots com Main roads 100 3582.4 3051.0 pletely dominated by M. perfoliata. The proce

Bariloche dure was repeated on the same plot ca. 30 and Abandoned fields 80 287.2 219.2 60 days later, with the following results (in Urban & suburban grams). vacant 10ts 193 1253.5 392.8 Orchards 65 2938.8 3064.0 Streets and pathways 191 1008.0 524 .0 October November December Totals Main roads 210 1326. 6 460 .0 Plot A 138.6 115. 1 22.3 276.0 g. Plot B 487.9 141. 9 96.7 726.5 g. Plot C 381.0 398.6 48.5 828.1 g. TABLE 6

Food yield (g) per minute in Coatepec, Mexico. Mean On the basis of 34 samples where M. per values based on 5 samples foliata was abundant, food biomasses varied 2 Species Coffee Sugar cane Dirt Vacan! from 108.5 to 973.6 g per 0.25 m plot. Mean plantations plantations roads lots value 275.9 ± 210.6 g (SD). The aerial parts of this plant are 100 edible. Average water con Bidens odorata 5.3 % Commelina diffusa 11.8 12.8 13.8 tent varied around 78.5 ± 7.3 %. Commelina erecta 18.2 Drymaria gracilis 14.6 10.8 Galinsoga quadriradiota 2.3 Plantago lanceolata Heliconia caribaea 110.2 Leaf fresh weight per 0.25 m2 plots (n = Hydrocotile bonariensis 4.8 1.7 25 plots) showed figures ranging from 39.2 to Hydrocotyle mexicana 4.0 Oxalis latifolio 4.5 309.2 g. Mean value 124.1 ± 60.2 g. Seeds 23.8 37.8 Rumex obtusifolius should be added to this food source. At the end 5.0 Sida rhombifolio 2 Spilanthes americana 5.2 4.9 6.0 of the summer, we selected three 1 m plots Xanthosoma robustum .33.2 29.4 15.0 21.6 showing ripe fruits. On average, there were DÍAZ et al: Weeds as a source for human consumption 335

TABLE7

Proportions of food plants in different biomes and communities

Natural Ecosystems

Total No. edible No. spp. spp. % Site Source

18 ,956 1;112 6 NorthAmenca. Foodplan:ts used by-- Dukei992 *- the aboriginal populations 2,500 375 15 Sonoran Desert Felger & Nabhan 1978* 430 26 6 Tierra del Fuego, Ona Indians (1) Martínez-Crovetto1968 360 75 21 Bolivian Amazon Boom 1987 275 11 4 Peruvian Amazon (only fruit trees Peters et al. 1989 considered)

Anthropic Ecosystems

653 124 19 SW Córdoba Province, Argentina Bianco & Cantero 1992 446 77 17 W Uruguay, E Entre Ríos Prov., Lema 1988 Argentina, S Brazil (Salto Grande Dam) 165 55 33 Parque La Chata, La Habana, Cuba E.H. Rapoport, C.R. Martínez, P. Herrera (unpublished)

Strict1y Weeds

51 31 61 Experimental Field, Saskatchewan Derksen et al. 19 93 14 6 43 Slash & bum, NE India Misra et al. 1992 761 177 23 Weed Catalog, Argentina Marzocca lit al. 1976 300 90 30 Weeds and escapes, NW Patagonia Rapoport & Brión 1991 200 59 30 Random samp1e, World Weeds Rapoport unpublished 40 20 50 Most cornmon weeds of Cuba Sánchez & Huranga 1970 176 51 31 Urban weeds, Rosario City, Argent. Franceschi 1996 168 111 66 Canadian weeds Frankton & Mulligan 1977 422 177 42 U.S.A. weeds Wilkinson & Jaques 1979 305 137 45 Xalapa City, Menco Domínguez-Barradas 1995 18 16 89 World's most aggressive weeds Holm et al. 1977

* Data provided by the authors. The rest was assessed by us in Kunkel's (1 984 ) list and our own records.

(1 ) Of the 9 Ona Indians extant only 6 were interviewed. They were very old people and only one woman used Shelknam language exclusively. Of the 430 native vascular species of the island 24 were used as food (5.6 %). Two additional native edible plants were iguored by the reporters. From 128 exotic species only Hypochaeris radicata and Taraxacum officinale were included in their diets, although there are7 more species which appear as edible in Kunkel's listo

356.0 ± 38.4 spikes/m2 in highdensity patches. Of course, it would imply the design of ade spike may contain about 500 seeds mea quate mechanical technology to accelerate the Each suring 2 mm each, showing about 36 % abor process of screening seeds. Average water con tions. Viable seeds were assessed in 162.1 glm2• tent of leaves varied around 78.6 ± 4.9 %. Although the process is laborious (about one hour-person to screen the seeds of one square Rumex acetosella meter), it is useful to know that a one hectare Yields vary between 8.9 and 186.7 g/0.25 monospecific plot may yield more than 1.5 tons m2. Mean 53.3 ± 47.9 g = 15 samples). The (n of seeds, in addition to almost 5 tons of leaves. species is widely distributed in disturbed and 336 REVISTA DE BIOLOGÍA TROPICAL undisturbed habitats, especially in sunounding from the occasional gathering to a more per grasslands and pasturelands. Average water manent cultivation of "weeds". Popular mar content varied around 77.1 ± 4.6 %. kets in Mexico (Linaresand Aguirre 1992) and Korea (Pemberton and Lee 1990) offer a vari Taraxacum officinale ety oí' gourmet "weeds" at higher prices than Yields varybetweel1 11.2 al1d 107.4 g/0.25 the common vegetables. m2 (central ribs excluded). Mean 47.2 ± 27.6 g A case of human-livestock-plant mutual (n = 17 samples). Average water content vm'ied ism is mentioned by Kuznm' (1993), especially around 82.2 ± 4.7 %. refened to species of Chenopodium proliferat ing in unusual concentrations in corrals. Herd animals transport these forage species to pas DISCUSSION toral campsites where the plants thrive in the organic corral soils. This creates a mutllally Common weeds prove to be an interesting beneficial relationship where certain plant resource in sma11 to medium-sized human set species become camp followers of pastoral tlements where they may provide supplemen campsites. This is the process by whích plant tm'y food. In large cities, suburban populations invaders reach the status oí' weeds first and, may also profit from edible weeds. The data later on, the status of cultivars, according to from Table 7 show that edible, non-weedy Vavilov (1938). And this process may explain plants comprise between 6 and 21 percent of the fact that the majOlity of the most aggres the biomass of the natural communities sur sive and cosmopolitan weeds are edible. veyed. The proportion of edible plants increas Inítially, plant domesticatíon began early, and es considerably in anthropic environments, in an unconsciolls way, probably in the especially in weed communlties. Roughly, ten Paleolithic Age, in primitive hunter-gatherer percent of the 260,000 known vascular species cultures (Rapoport et al. 1995). lt is interesting of the world should be considered as a poten to note that Jeaf-cutting ants (Acromyrmex), as tial source for human consumption. It is prob determined Fmji-Brener(1996), show clear by ably not by mere chance that the majority of foraging preferences for exotÍc roderal weeds the centers of origin or domesticatíon of culti which, accordil1g to Coley et al. (1985), are vated plants proposed by Vavilov (1938) corre plants that invest more energy in reproduction, sponded to ancient, sedentary cultures. The growth and dispersal than in anti-herbivore idea that civilizatlons arose in areas with abun chemical defenses. It is suggestive that 52% of dant edible plants adequate for culturing 1S the early introductions (archaeophytes) in probably incorrecto Since edible plants abound Poland listed by Trzcinska (1982) are edibJe. everywhere, it seems that civilizations devel Our results show that in anthropíc habitats oped in any environment where for historical there are immense amounts of edible plants reasons, people had time enough to exploit which are not always totally profited from. their natural resources in a more permanent This is clearly evident in Argentina where peo and intensive way. By selection, plants origi pIe have almost lost the ancient practice of naUy wild, began to be more productive and gathering wild food plants. In a tropical m"ea adequate for human consumption. Rye, oats, such as Coatepec, the overall 'standing crop' carrots and several other cllltivatedplants orig averages 2.1 tons/ha whilst in temperate inated as weeds, a fact that gives a c1em' idea of Bariloche it reaches 1.3 tonslha. Tropical the enormOllS potential of weeds and other weeds are richer in species number and more wild non-weedy plants as a source for new cul productive than temperate weeds. The latter tures. The economic incentive provided by the are almost absent during the long winter sea revival of ancient gastronomic traditions per son, althollgh they can be dehydrated and suaded some private entrepreneurs lo change cooked during the cold season. el al: Wéeds as a source fGj'hUlnall consumption 337 DÍAZ

Because a signifieant seetor of Bianc(j, C.A. & ]J. Cantéro. 1992. Las p¡antasvas�ulares . the de suroeste de i Argentine population . suffers ' serious l la Prov ncia de Córdoba. kOl1ografía. from Facultad AgronOlnía y Veterinaria. Universidad problems of malnutritlOn, the Universidad del Nacional Río Cuarto, Río Cuarto, Argentina,p. 229 Comahue de Bariloehe and' Municipalidad booklet (Rap()port et published a al. 1997) Boom, B. M. 1987. Ethnobotanyof the Chácobo Indians, illustrating the most common edible weeds. Beni, Büllvia. Adv. Econ. Bot. 4: 1-68, 20 Free copies were distributed in pub- provincial . schools, Clarke, eE. 1 977 I�dible and useful phmts of California. - líe This il1struction manual represents of Califórnia,�erk eIey, California. p. 280. the beginning a program whích hopes to of restore, at partially, our ancestors' knowl least Coley. PO., J,P, Briant & ES. Chapin. 1985. Resource edge. result this printed information availabiJity and plant ami-herbivore defense. Science As a of and a television program, a substantíal incre 230: 895-899. ment popular awareness and utilizatian of af Derksen, D. A, A. G. TIlOmas, G. P blfol1(l, H. A i"oeppky resource,. was register d. e & e J. Swanton. ¡ 993, Impactof agmnomic pracc• tices on weed communities:Fal1ow within til1age systems. Weed Sci. 42: Itl4-194.

ACKNOWLEDGEMBNTS Dbminguez Barradas, B, A. 1995. La'!egetación vascular espontánea en calles y banquetas . de la Ciudad de Our thanks to Andrea Premolí, Tom Xalapa, Veracruz Tesis Licenciatura, Universidad Barba.ra Drausal their useful . , Wíthamand for Veracruzana, Facultad de Biología, Veracmz comments on the article: México. p, 93.

Duke, J. A. 1992. Hruldbobk al' edibleweeds, CRC, Boca Raton, Florida. p, 246, RESUMEN ElCciola, S. 1990. CornucopíaoAsourcebook of edible Las malezas abundan en ambientes urbal'ios y plants;Kampong, vista, Callfomia. p.678. , rurales.. Según la. regioú y lugar hasta el 6Mb delils especies de malezas pueden ser comestibles y constituir un FAO, 1987. ProduclÍbn jeitrbook. andAgricultúre, recurso alimentalÍo adicional para el �er humano. Sobrela Organization, United.Na1Xüns, ROme: 1-306. base de 400 muestras cje1/4 m2cada 1111a, recolectadas el! áreas tropicales (rutas, tem;no,8 baidíos, c.r,lles y plafl.ta Farjí-BreneJ', 1996, Posibles vías de.exp,insión de la ciones en Coatepec, México) el promedio de lahQrnasaen hotmí¡sacortadora de hojas /Í.cromytmex ¡ubicotni!>' . peso fresco varió entre 1 277 y 3 582 l;:glha. Un muestreo . baciala . Ecol6gía.AuslnÜ 6:. f44-150. simÜar en ',m área templada (739 muestrq� ,en Bar1lóche, Axgentina) ¡¡croJó valores medios entre 287 y 2. 939 kgrh.a. En total se rezistraron 43. especies en Coat�.pec y 32 Fe!g·"r., ¡¡ud Nahhan, i 978. Agroecosystem O especies en B;,siloche. La 111ediag eneral di\¡�rsity; P.. rnodel from ¡he S lloran deserto AAAS y 1.3 ton/ha, .respectivamente. A una (Am, Assoc, Adv. Sei ) Selected Symposia 10. mayor, una cornparación enrn! las rr\a¡E;�as n\¡�Xi,;arl:rs y argentinas no rlJo�tr{:) nlayores varia�ciones regtonaJes en FrrulCe,chi,E,A, 1.996. The ruderal vegetatillll of Rosario CUrulto ¡¡ qué partes u órganos son los .:;ornestibles. En City, Argel,:11w.Landscape Urb. Plann, 34: 11-18. ambos . lugarcs, el orden· de aprovec:hamiento, de mayor a menor. fue: hoja�, semillas, raices,'rrutos, m¡:US:IODLe;s. Frankton, e & G.A; Mu!Hgé,n. 1(j·jJ. Weeds oL Ci,lllad,L res ji coücUmentO¡;, LaE n,ices (:omestibJes (.incluyendo Canada Deptartmcn! oL, Ag1'Ículture,PllbJicatior: b�Jlbos y 'rliOluas) pareceü ser n:(�tS c'oruunes entre. la}.; 94iL p, 217. especiec' perenne8 que cntre las Godwin, H. 1969. The historyof in Britain. p. 1-10. In: The bio]ogy of weeds. J.L, Harper (ed.), Blaekwdl, Oxford, U,K

A!louymol\1,.. ·199<. Cat<.'\logo de espede" vegetales consj· Gómez, C.M. & M. Sotn, [990. Climático del Municipio malezas, ,A,soc. Melí, Ciencia de la Maleza, de Coatepec. Instituto de Ecología, PubL No. 27, AMCM Méxi.co, D.E p. 92, :Xalapu¡ Ver3.crllz�:)\t1éx'ico. 338 REVISTA DE BIOLOGÍA TROPICAL

Grigera, D., E. Bianchi, e. Brión, J. Puntieri & N. and bum agriculture) and terracecultivation in north Rodríguez. 1989. Carta del medio ambiente y su east India. Agric., Ecosyst. Env. 41: 285-295. dinámica de San Carlos de Bariloche, 1987 . Universidad Nacional del Comahue, Bariloche, Pemberton, R W. & N. S. Lee. 1996. Wild food plants in Argentina. p. 40. South Korea: market presence, new crops, and exports to the United States. Econ. Bot. 50 : 57 -70. Harris, B.e. 1969. Eat the weeds. Keats Publishing Inc., New Canaan, Connecticut, p. 254. Peters, e. M., A. H. Gentry & R O. Mendelsohn. 1989. Valuation of an Amazonian rainforest. Nature 339: Holm, L.G., D.L. Plucknett, J.v. Pancho & J.P. Herberger. 655-656. 197 7. The world's worst weeds. University of Hawaii, Honolulu, Hawaii, p. 609. Rapoport, E.H., & e. Brión. 1991. Malezas exóticas y plantas escapadas de cultivo en el noroeste patagóni King, L. W. 1966. Weeds of the world. Biology and co. Segunda Aproximación. Cuadernos de Alter Control. Leonard Hil!, London. p. 526. Natura No. 1, Bariloche, Argentina. p. 19.

Kunkel, G. 1984. Plants for human consumption. Koeltz Rapoport, E.H., L.S. Margutti & E.H. Sanz. 1997 . Plantas Scientific Books, Koenigsten, Gerrnany. p. 393. silvestres comestibles de la Patagonia Andina. Parte 1. Exóticas. Programa Extensión Universitaria, Univ. Kuznar, L.A. 1993. Mutualism between Chenopodium, Nac. del Comahue, Depto. Ecología, CRUB, herd animals, and herders in the south central Andes. Bariloche, Argentina. p. 51 . Moun. Res. Dev. 13 : 257 -265. Rapoport, E.H., E. Raffaele, L. Ghermandi & L. Margutti. Ladio, A.H., E. Raffaele, L. Gherrnandi, M.E. Díaz 1995. Edible weeds: A scarcely used resource. Bull. Betancourt, l. López-Moreno & E.H. Rapoport. Eco!. Soco Amer. 76: 163 -166. 1998. Las malezas en las ciudades de S.e. de Bariloche y Coatepec y su potencial oferta alimenta Rudloff, W. 1981. World-Climates. Wissenschaftliche ria. Actas XIII Congr. Latinoam. Malezas, Buenos Verlagsgesellschaft, Stuttgart, Germany. p. 632. Aires, Argentina. Sánchez, P. & H. Huranga. 1990. Malezas importantes de Lema, O. W. 1988. Catálogo ilustrado de la flora de Salto Cuba. Instituto de Investigación Fundamental de Grande. Introducción a su estudio. Tomo l. Comisión Agricultura Tropical A. de Humboldt, Ministerio de Técnica Mixta de Salto Grande, Argentina-Uruguay. Agricultura, Cuba. p. 63 . p.312. Tanji, A. & Nassif, F. 1995. Edible weeds in Morocco. Linares, E. & J. Aguirre (eds.) 1992. Los quelites, un Weed Techno!. 9: 617 -6 20 . tesoro culinario. Universidad Autónoma de México & Instituto Nacional de la Nutrición "Salvador Trzcinska-Tacik, H. & K. Wasylikowa. 1982. History of Zubirán", México. p. 141. the synanthropic changes of flora and vegetation of Poland. Mem. Zool. 37 : 47 -69. Michael, P. 1980. AH good things around uso A cookbook aud guide to wild plants and herbs. Holt, Rinehart & UNe. 1983.Cartas de precipitación de las provincias de Winston, New York, p. 240. Río Negro y Neuquén. Facnltad Ciencias Agrarias, Universidad Nacional del Comahue, Cinco Saltos, Martínez-Crovetto, R. 1968 . Estudios etnobotánicos. Argentina. IV. Nombres de plantas y su utilidad, según los indios onas de Tierra del Fuego. Etnobiologica 3: Vavilov, N.!. 1938. Los centros genético-geográficos de 12 -19. las plantas cnltivadas. Rev. Fac. Agron. Univ. Nac. La Plata 22: 65-94 . Marzocca, A., O.J.V. Mársico & O. Del Puerto. 1976. Manual de malezas. Hemisferio Sur, Buenos Aires, Wilkinson, RE. & H.E Jaques. 197 9. How to know the Argentina. p. 564 . weeds. W.C. Brown, Dubuque, Iowa p. 230 .

Misra, J., H. N. Pandey, R S. Tripathi & U. K. Sahoo. Znrlo, e. & M. Brandao. 1990. As ervas comestíveis. 1992.Weed population dynamics under 'jhum' (slash Globo, Sao Paulo, Brazil. p. 167 .