Didymopanax morototoni (Aubl.) Decne. & Planch. Yagrumo Macho

Araliaceae Ginseng family L. H. Liegel

Yagrumo macho (Didymopanax morototoni) is a Soils and Topography well-known pioneer species throughout the tropical Americas. In commerce, the common name is Yagrumo macho is not exacting in soil require- morototo or matchwood because the wood is used for ments. Therefore, it grows well on a variety of soils, match splints in several countries. The light weight especially those that have been abandoned after wood is also substituted for certain grades of balsa. agricultural use. In Trinidad, stands are found on flat areas having deep, bleached sands (Entisols) and on gently undulating areas having outcrops of acidic Habitat clays (Ultisols or Inceptisols) (2,19). In Puerto Rico the species grows most commonly on either deep or shallow acid clays (Ultisols and Inceptisols) in the Native Range mountains or on calcareous soils (Mollisols) in the “haystack” (mogote) limestone hills. Yagrumo macho is the most widely distributed Although yagrumo macho grows on flat areas in species within the genus Didymopanax. The range is Puerto Rico, particularly near streams, it is more (17) extensive, roughly from latitude 17” N. to 25” S., and predominant in upland dissected terrain from covers wet and moist forests of the West Indies, from 100 to 900 m (330 to 2,950 ft); slopes are usually 45 Cuba to Trinidad, and continental tropical America percent or more. On the western end of Puerto Rico, from the States of Oaxaca and Veracruz in Mexico, it grows almost at sea level (21). The highest eleva- through , , the Guianas, , tions reported for yagrumo macho are in Colombia, and Argentina (4,12,X,23,25,26,33). The species was where it can be found from 500 to 1700 m (1,640 to 5,580 fi) (28). introduced to Jamaica and has been planted in southern Florida. In Puerto Rico it is quite common, growing in over half of the municipalities and in 8 of Associated Forest Cover 13 State Forests, but it is not common anywhere else in its range. In Panama it is reportedly more abun- Throughout its range yagrumo macho is a common dant on the Pacific side than on the Atlantic side. species in secondary forests, in natural or man-made Local or regional range maps are known only for openings in mature forests, or along roadsides and Colombia and Puerto Rico (13,16,28). river banks. In Puerto Rico’s Subtropical Wet Forest it is often associated with yagrumo hembra or trum- pet-tree (Cecropia peltata) and guano or balsa Climate (Ochroma pyramidale), which are also fast-growing, large-leafed successional species having similar physiognomies (10). In openings caused by blow- In Puerto Rico yagrumo macho grows in Subtropi- downs it is also associated with tabonuco (Dacryodes cal Moist, Subtropical Wet, and Subtropical Rain excel@, the mature component in natural remnants Forest life zones (10). Mean annual temperatures in of the Subtropical Wet Forest in Puerto Rico. these life zones range from 24” to 26” C (75” to 79” In the State of Oaxaca, Mexico, yagrumo macho F), 22” to 24” C (72” to 75” F), and 22” to 23” C (72” grows with other thicket species like pegoge (Taber- to 73” F) with mean annual precipitation of roughly naemontana arborea), mata-raton (Gliricidia 1500, 3000, and 4000 mm (60, 120, and 160 in), sepium), Vernonia patens, Acacia globulifera, respectively. Elsewhere, yagrumo macho grows in camasey (Miconia spp.), Belotia cambellii, and cerezo similar life zones, and mean annual precipitation (Cordia glabra) (32). Three locally important and as- may exceed 5000 mm (200 in) in some parts of the range, as in Colombia (28). sociated hardwood species in Trinidad are gommier (Protea insigne), Sterculia caribaea, and serette (Byr- sonima spicata) (2). In Venezuela yagrumo macho The author is Soil Scientist, Pacific Northwest Research Station, and yagrumo hembra form a transition zone between Portland, OR. (Research on this species was done in cooperation guaba (Inga spp.) stands growing along the rivers with the University of Puerto Rico, Rio Piedras.) and high forest stands of pendula occurring

288 Didymopanax morototoni

further inland (34). In the Bajo Atrato region of seeds is quite small and germination is extremely Colombia it is associated with Simarouba spp., box- poor. Of over 800 individual seeds collected at one wood (Jacaranda copaia), and Schizolobium site in Puerto Rico, only 5 were viable (21). parahybum (20,22). Highest germination percentages recorded were 30 percent after 70 days in Brazil and 35 percent after Life History 40 to 90 days in Costa Rica. In Brazil the seeds were soaked for 9 to 10 hours in an unspecified chemical, Reproduction and Early Growth covered with a thin layer of soil, and protected from direct sunlight. Seeds in Costa Rica were treated Flowering and Fruiting-Yagrumo macho has with a 3 percent solution of sodium hypochlorite (21). perfect flowers and reproduces in a yearly cycle. Of After germination periods of 52 to 120 days, only 12 96 trees observed for 14 months between 1976 and of 300 seeds germinated in three trials in Puerto 1977 in the Luquillo Mountains and at the Rio Rico. Several soaking treatments with 9 iV sulfuric Piedras Agricultural Experiment Station in Puerto acid were used. Old records from Trinidad show that Rico, 58 flowered mainly from October through treating with unknown hormone solutions and December (21). There was significantly less flowering human urine aided seed germination. in other months. Minimum sizes of trees producing Some 16 bird species feed on yagrumo macho seed fruits were 6.4 m (21 ft) tall and 10.2 cm (4 in> in or fruits in Puerto Rico. This may provide a plausible d.b.h. In Trinidad, flowers have been observed main- reason why good germination in the field cannot be ly in October but also in April and September (19). duplicated in laboratory or nursery conditions. Information on flowering in other countries is not Studies have shown that after seeds are ingested by available, but with yagrumo macho’s rather extended birds, they are subjected to scarification in the giz- range, great latitudinal variation in flowering and zard and chemical treatment by gastric juices in the fruiting can be expected. Flowers are numerous and stomach (20). Although attempts to germinate seeds grouped at ends of branches into many rounded taken from bird feces have failed in Puerto Rico, they clusters, from 0.3 to 0.6 m (1 to 2 ft) long. The 5 have been successful in Costa Rica. It is also petaled, fine brownish and gray hairy flowers are proposed that some species feed only on the outer about 5.0 mm (0.2 in) across, with white petals about coat of yagrumo macho seed and others feed on the 1.5 mm (0.06 in) long, and five stamens and two seed endosperm. Thus dormancy could be broken by styles (16,21). mechanical puncturing or breaking of the seed coat. Pollination mechanisms have not been studied in Until further evidence is gathered, it can be assumed detail. Bees of the Tkigona and Mellipona genera that birds play the primary role in germination and have been observed on yagrumo macho flowers in dissemination of yagrumo macho seed. In Trinidad, Costa Rica. Ants of the Crematoguster genus may bats also act as dispersal agents (3). also play a role. Yagrumo macho seed is unwinged and heavy. Of It takes approximately 1 to 2 months for flowers 341 fruits and 125 individual seeds collected beneath to develop into fruits. Immature fruits are dark green or deep purple. They are fleshy, 4 to 6 mm (0.16 to one tree in Puerto Rico, all came from one quadrant 0.24 in) long, 7 to 10 mm (0.28 to 0.39 in) wide, and around the tree’s base. about 2 mm (0.08 in) thick. Fruits usually contain two and occasionally three oblong and flattened Seedling Development-Germination is epi- brown seeds, about 5 mm (0.2 in) long. Mature fruits geous. Few studies document seedling growth of are dropped almost every month in Puerto Rico, but yagrumo macho in either field or nursery conditions. production peaks from November through June (21). Early growth is fairly rapid and best when seedlings In Costa Rica fruits mature in January and fall from are exposed to direct sunlight. In Brazil, d.b.h. and February through May. height mean annual increments (MAI’s) were 3.0 cm (1.2 in) and 1.7 m (5.6 ft) for 2-year-old plantations Seed Production and Dissemination-Seed (5). A 7-year-old plantation had mean annual height production for yagrumo macho is an almost con- and d.b.h. increments of 1.7 m (5.6 ft) and 19 mm tinuous process, as it is for other successional (0.8 in). A 20-month-old plantation in Bajo Atrato species. Seeds have a hard, impermeable outer coat; region of Colombia, planted at 3- by 3-m (9% by they can thus remain on the ground for a long time 9%ft) spacing, had very good form and fine branch- and still retain viability to germinate when openings ing, with a branch angle usually greater than 70”. in the canopy occur. When seed is collected and taken Height and d.b.h. averaged 8 m (26 ft) and 12 cm (4.7 away from field conditions, the number of viable in) (20).

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Table l-Mean annual increment by diameter clas- ses for yagrumo macho (Didymopanax morototoni) measured over a 7-month period within the Luquillo Mountains in Puerto Rico (21)

Trees D.b.h. classes Mean annual increment at b.h. sampled cm cm no. 10 x 10 m quadrant 0.0 to 0.5 0.52 0.5 to 1 .o 0.53 1.0 to 1.5 0.56 1.5 to 2.0 0.35 50 x 50 m quadrant 0.0 to 2.5 0.86 5 2.5 to 5.0 1.30 10 5.0 to 7.5 2.46 18 7.5 to 10.0 1.40 2 in in no. 33 x 33 ft quadrant 0.0 to 0.2 0.20 0.2 to 0.4 0.21 0.4 to 0.6 0.22 0.6 to 0.8 0.14 164 x 164 ftquadrant 0.0 to 1.0 0.34 5 1.0 to 2.0 0.51 10 2.0 to 3.0 0.97 18 3.0 to 4.0 0.55 2

An MA1 of 5.6 mm (0.22 in) in diameter was recorded in Puerto Rico for 20 individuals, where the initial overbark d.b.h. was mostly between 5 to 15 mm (0.2 to 0.6 in) (table 1). Growth was somewhat irregular when related to size class, perhaps because of crown position and the fact that some trees were exposed to direct sunlight and others were not. Mor- tality for the 20 individuals was 5 percent in 1 year and was attributed to vine overgrowth (21).

Vegetative Reproduction-Yagrumo macho wildings transplant readily and the species ap- Figure l-Naturally regenerated yagrumo macho in the Luquillo parently reproduces by coppicing (19,221. In Puerto Mountains, PR. Note the good natural pruning and umbrella-like Rico sprouting was seen from stems broken off by crown. wind but not on stems killed by lightning (21). Cut- tings were used in Brazil (5). at the base, and has a ringed appearance. Natural Sapling and Pole Stages to Maturity pruning in the lower half is excellent (fig. 1). Yagrumo macho cannot be included in biomass es- Growth and Yield-Mature yagrumo macho may timations from regression equations because of its reach a height of 30 m (100 ft) and a d.b.h. up to 36 unusual umbrella-like crown (8). The outer bark is cm (14 in) (6,291. More commonly, as in the Luquillo smooth and gray and the inner bark has a slightly Mountains of Puerto Rico (17), the tree is of medium bitter or spicy taste (16). Maximum age is probably height and diameter, 15 to 17 m (49 to 56 ft) and 20 between 35 and 50 years (21). Rooting is reportedly to 22 cm (8 to 9 in). The bole is cylindrical, swollen superficial.

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Table a--Mean annual increment for yagrumo ses, it was statistically lower at lower elevations, macho (Didymopanax morototoni) within the Luquil- where it was 1.9 mm (0.07 in) per year, than at lo Mountains of Puerto Rico, 1957 to 1975 (9) higher elevations, where it was 3.7 mm (0.15 in) per year (9). Item Sabana 8 Rio Grande Sabana 4 Mean annual increment Rooting Habit-No information available. Diameter-mm 3.3 3.1 5.3 -in 0.13 0.12 0.21 Reaction to Competition-Yagrumo macho is Basal area-cm2 11.1 10.6 23.4 classed as intolerant of shade. When planted in full -in* 1.8 1.7 3.7 sunlight it exhibits its best growth and reproduction Trees-number 134 36 23 and may be very aggressive against other species. Elevation -m 180 to 360 420 to 600 210 to 600 Over a 2- to 6-year d.b.h. measurement period in --ft 590 to 1,181 1,378 to 1,968 689 to 1,968 Rainfall -mm 2290 3300 3560 tabonuco forests in Puerto Rico (11, MAI of yagrumo -in 90 130 140 macho was 3.3 mm (0.13 in). Two more tolerant species found in the same locality, palo de matos (Ormosia krugii) and ausubo (Manilkara bidentata), averaged 5.1 and 6.6 mm (0.20 and 0.26 in). Other Growth or yield data for mature trees are scarce work in Puerto Rico indicates that many species since yagrumo macho is harvested for local markets growing in association with yagrumo macho have and is seldom grown under intensive plantation con- larger periodic diameter increments, probably be- ditions. Limited data on diameter growth are avail- cause they are more tolerant of shade (31). able for older stands in Puerto Rico. Ten-year d.b.h. Few special silvicultural systems for yagrumo macho are found in existing literature. Some 30 measurements in mature tabonuco forests in the Lu- years ago in Trinidad, a policy of “let nature heal quill0 Mountains showed an MAI from 1.5 to 4.6 mm herself” was followed when reforesting degraded or (0.06 to 0.18 in) (30). Observed growth differences poor sites (3). Yagrumo macho was one of 18 timber appeared to be related to crown position, with sup- species whose natural regeneration was allowed to pressed trees growing least. Eighteen-year d.b.h. grow under a high shelterwood system (2). In Brazil measurements showed MA1 rates from 3.3 to 5.3 mm there are pure yagrumo macho plantations designed (0.13 to 0.21 in) on three sites (table 2) (9). The to produce wood for match splints (5,27). Because highest rate was found at Sabana 4, where yagrumo yagrumo macho rapidly colonizes open areas and is macho is a component of mature tabonuco forests. intolerant, some sort of selective clearcutting is When analyzed across all three sites, growth dif- needed to promote adequate regeneration by natural ferences between crown classes were not positively seeding. After cutting, yagrumo macho is one of the correlated with increasing crown dominance. Meas- first species to become established. It should then be urements in the Toro Negro State Forest from 1951 one of the first to be cut for commercial use, selec- to 1976 showed MA1 growth for yagrumo macho at 5 tively leaving more valuable species to be harvested mm (0.2 in) (31). later in the established rotation cycle. Mean annual d.b.h. growth rates observed in Puer- to Rico do not even approach the 10 mm (0.39 in) Damaging Agents-Several agents cause damage figure sometimes quoted for mature rain forest tree or death to saplings or mature trees. The most com- species in the tropics. They are also surprisingly slow mon is probably wind, which can break off branches for a reportedly fast-growing successional species. Yet or uproot entire trees. Wind damage is most acute on caution should be used in interpreting these data very wet, steep sites where saturated unstable soils because of the long measurement intervals used that cannot provide adequate anchorage for roots. In the could cancel initial fast growth spurts occurring after Luquillo Mountains, climbers or stranglers like successful regeneration was established (table 1). Clusia griesebachiana and morning glory (Ipomoea Data from Puerto Rico for yagrumo macho and spp.) are common to wetter sites and have caused yagrumo hembra, also a successional species, show branch breakage or death of larger seedlings or sap- that periodic diameter growth for codominant, inter- lings. mediate, and suppressed trees is comparable. This Yagrumo macho is apparently free from serious suggests that a dominant position is required before diseases in nursery and field conditions, but several good diameter growth is shown. Finally, although insects (Scarabaidae and Pyraustidae) consume periodic d.b.h. growth of older yagrumo macho in either foliage or woody tree material in Puerto Rico. Puerto Rico was not related to initial diameter clas- Young trees are sometimes killed by grazing cattle in

291 Didymopanax morototoni

rural areas. Clearing land for agricultural or other 2. Ayliffe, R. S. 1952. The natural regeneration of Trinidad development often causes widespread mortality. forests. In Proceedings, Sixth British Commonwealth Forestry Conference, Ottawa, ON. 19 p. 3. Beard, J. S. 194445. A silvicultural technique in Trinidad for the Special Uses rehabilitation of degraded forest. Caribbean Forester 6:1-18. 4. Brooks, R. L. 1935. Forests and forestry in Trinidad and Yagrumo macho’s specific gravity is between 0.35 Tobago. In Proceedings, Third British Empire Forestry and 0.60. Mechanical and physical properties of the Conference, South Africa. 26 p. 5. Buch, C., and J. H. M. Lima. 1973. Morototo no reflorestamento wood are somewhat higher than those of yellow- do norte e nordeste brasileiro. In Proceedings, Second poplar (Liriodendron tulipifera) (6,149. Yagrumo Brazilian Forestry Conference. Curitiba, Brazil, September macho is used for general carpentry and interior con- 17-2Ll973.5 p. struction (18). It is also suited for crates and boxes, 6. Chudnoff, Martin. 1984. Tropical timbers of the world. USDA utility plywood or core stock, match splints, even Forest Service, Agriculture Handbook 607. Washington, DC. particleboard, and could probably be substituted for 464 p. heavier grades of balsa (16). Felled timber is very 7. Chudnoff, M., and E. Goytia. 1972. Preservative treatments susceptible to decay and fungal attack if not con- and service life of fence posts in Puerto Rico, progress report. verted almost immediately. Penetration and absorp- USDA Forest Service, Research Paper ITF-12. Institute of tion of treating solutions, either in open or pres- Tropical Forestry, Rio Piedras, PR. 28 p. surized tanks, is fair but can be improved 8. Crow, T. R. Common regressions to estimate tree biomass in tropical stands. Forest Science 24:110-114. considerably by incising untreated material first. 9. Crow, T. R., and P. L. Weaver. 1977. Tree growth in a moist Nonincised posts, cold-soaked for 5 days in a lo-per- tropical forest of Puerto Rico. USDA Forest Service, Research cent solution of pentachlorophenol dissolved in diesel Paper ITF-22. Institute of Tropical Forestry, Rio Piedras, PR. fuel, lasted from 9 to 26 years in graveyard tests in 17 p. Puerto Rico. Double diffusion treatment with several 10. Ewel, J. J., and J. L. Whitmore. 1973. The ecological life chemicals gave similar results, but cold-soaking with zones of Puerto Rico and the U.S. Virgin Islands. USDA only a &percent solution of pentachlorophenol dis- Forest Service, Research Paper ITF-18. Institute of Tropical solved in diesel fuel was far inferior, the life expec- Forestry, Rio Piedras, PR. 72 p. tancy being only about 3 years (7). 11. Fanshawe, D. B. 1954. Forest products of British Guiana. Yagrumo macho leaves are used for home remedies Part 1. Principal timbers. British Guiana Forest Department, Forestry Bulletin 1,2d ed. Georgetown. 106 p. in some countries (16). Special uses of the wood in 12. Fors, Albert0 J. 1937. Las maderas cubanas. Imprenta y include drums and canoes (11). Brazil has Papeleria de Rambla, Bouza y Ca., La Habana, Cuba. 106 p. tested yagrumo macho suitability for ethanol produc- 13. Holdridge, L. R. 1970. Investigation y demostraciones tion along with 24 other tree species (24). Yield was forestales. 1968. Panama. Manual dendrologico para 1000 299 liters (79 gal) per ton of raw material, close to especies arboreas en la Republica de Panama. Programa de the maximum yield of 315 liters (83 gal) per ton las Naciones Unidas para el Desarrollo. PNUD/FAO Pub. registered for Protium spp. FOR:SF/PAN 6. Informe Tecnico 1. FAO, Rome, Italy. 325 p. 14. Laboratorio de Tecnologfa de la Madera de1 Instituto Interamericano de Ciencias Agrfcolas. 1968. Informe sobre un Genetics programa de ensayo de maderas realizado para el proyecto UNDP-192. Investigation y Desarrollo de Zonas Forestales Existing literature shows no references to genetic Selectas de Costa Rica. Turrialba. 131 p. or tree breeding research for yagrumo macho. Wide 15. Little, Elbert L., Jr., 1973. Arboles de1 noreste de . natural variation in genetic traits would be expected Programa de Desarrollo de las Naciones Unidas, Instituto de for yagrumo macho because of its extensive natural Foment0 National y la Organization Mundial para la Agricultura y la Alimentacion. Document0 de Trabajo 2A, range and the fact that it grows in several life zones FO:SF/NIC 9, No. 13. FAO, Rome, Italy. 77 p. under varied environmental conditions. Since there 16. Little, Elbert L., Jr., and Frank H. Wadsworth. 1964. are also several other species within the same genus Common trees of Puerto Rico and the Virgin Islands. p. throughout Latin America, undescribed hybrids may 428-429. U.S. Department of Agriculture, Agriculture exist or might be possible if species were brought Handbook 249. Washington, DC. together under controlled laboratory or field condi- 17. Little, Elbert L., Jr., and Roy 0. Woodbury. 1976. Trees of the tions. Caribbean National Forest, Puerto Rico. USDA Forest Service, Research Paper ITF-20. Institute of Tropical Forestry, Rio Piedras, PR. 27 p. Literature Cited 18. Longwood, Franklin R. 1961. Puerto Rican woods: their machining, seasoning, and related characteristics. p. 93-94. 1. Anonymous. 1950. Tolerant species outgrow intolerants in U.S. Department of Agriculture, Agriculture Handbook 205. virgin rain forest. Caribbean Forester 11:68-69. Washington,DC.

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19. Marshall, R. C. 1939. Silviculture of the trees of Trinidad and 27. United Nations Development Programme. 1976. Forestry Tobago, British West Indies. Oxford University Press, development and research. Brazil. A tree improvement London. 247 p. programme for Amazonia. FAO Report FO:DP/BRa/71/545 20. Melchior, G. H. 1981. Personal communication. Institut fur Technical Report 3. FAO, Rome, Italy. 42 p. Forstgenetik und Forstpflanzenzuchtung. Ahrensburg 28. Venegas Tovar, Luis. 1978. Distribution de once especies (Holstein), Federal Republic of Germany. forestales en Colombia. Proyecto Investigaciones y Desarrollo 21. Nieves, Luis Oscar. 1979. Ecological life history study of Industrial Forestales COL!74/005. PIF 11. Bogota. 74 p. Didymopanux morototoni. Thesis (M.S.), University of Puerto 29. Vink, A. T. 1965. Surinam timbers, 3d ed. Ministry of Rico, Rio Piedras. 85 p. Development, Surinam Forest Service, Paramaribo, Surinam. 22. Record, Samuel J., and Robert W. Hess. 1943. Timbers of the 253 p. New World. p. 71. Yale University Pres, New Haven, CT. 30. Wadsworth, F. H. 1957. Seventeenth annual report, Tropical 23. Record, Samuel J., and Henry Kuylen. 1926. Trees of the Forest Research Center. Caribbean Forester 18:1-11. lower Rio Montagua Valley, Guatemala. Tropical Woods 31. Weaver, Peter L. 1979. Tree growth in several tropical forests 7:10-29. of Puerto Rico. USDA Forest Service, Research Paper 24. Reicher, Fanny, Sieg Odebrecht, and Joao Batista Chaves SO-152. Southern Forest Experiment Station, New Orleans, Correa. 1978. Composicao em carboidratos de algumas LA (Institute of Tropical Forestry, Rio Piedras, PR). 15 p. especies do Amazonia. Acta Amazonica 8:471-475. 32. Williams, Llewelyn. 1938. Forest trees of the Isthmus of 25. Roig, J. T. 1935. Cat&logo de maderas cubana. Estacion Tehuantepec, Mexico. Tropical Woods 53:1-11. Experimental Agronomica Santiago de las Vegas, Boletin 52. 33. Williams, Llewelyn. 1939. Maderas economicas de Venezuela. Secretaria de Agricultura y Comercio, La Habana, Cuba. Ministerio de Agricultura y Cria, Boletin Tecnico 2. Caracas. 77 p. 97 p. 26. Standley, P. C. 1932. Vernacular names of trees of the 34. Williams, Llewelyn. 1940. Botanical exploration in the middle Tapajoz River, Brazil. Tropical Woods 296-13. and lower Caura, Venezuela. Tropical Woods 62:1-20.

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