Excerptfrom: Costa Rican NaturalHistory, ed.Danief H. Janzen, pp.2O2-204. 1983.

Byrsonima crassifolia (Nance,Nancite, Shoemaker'sTree) W. R. Anderson This of the family Malpighiaceaeis a or a small about 7 m tall, though it reportedlygrows up to 10 m (fig. 7.28c). Interpreted broadly to include closelyrelated segregates, it rangesfrom southto Paraguay.It grows in lowland savannasand open, semi- deciduouswoods; indeed, in Central AmeicaByrsonima crassfolia (L.) H. B. K. and Curatella americana (Dilleniaceae)dominate many savannas.Like most sa- vannaplants , B . crassifoliais resistantto fire, andit often shows the twisted, even gnarled architectureof savanna '1 .The mafurefruit (fig. .28b)is a smallorange drupe with an edible exocarpand a single stonecontaining one to three . Birds dispersethe , and it seems likely that small ground animals do too, though no one has reportedsuch observations. The fleshis slightly oily and astringentbut not unpleasant,and the fruits are sold in marketsin Central America fuance)and the Amazon (murucfi. In the same regions a dnnk is made by re- moving the stones and mashing the flesh in water with ; this is delicious, either straight or fermented. Horses eat these fruits readily (D. H. Janzen, pers. comm.). In Bel6m one can relish the ultimate in exotica, muruci ice cream. The cortex of the stem has astringent chemicalsthat make it useful in tanning hides (byrsa is Greek for "leather"); this may explain its use in the preparation of various folk remedies such as febrifuges. The yellow and orange of crassifu- lia (fig. 7 .28a) aretypical of thoseof the , in which the flowers are very conservativerelative to other structures (Anderson 19'79).The only rewards for pollinatorsare andan oil that collectsin blisterson ACCOUNTS-

FIcune7 .28. a, Flowerof Byrsonimacrassifolia. b, to SantaRosa National Park. Guanacaste. Costa Rica. of B. crassifolia.c, LargeadultB. crassifoliaat entrance d, Maturefoliage (photos, D. H. Ianzen).

the large glandsborne on the abaxial side of the sepals. Many genera of Malpighiaceaehave extrafloral nec- Tiigorutbees take pollen from ttre flowers (K. S. Bawa, taries on the petiole or blade of the . These large B. Gates,pers. comm.), butitis not certainwhetherthey glands secretea sugary and are visited by ants. are effectivepollinators. The oil is collected by the fe- Costa Rican genera with such glands are , malesof certainanthophorid bees, most commonly Cen- ,andStigmaphyllon; all are vines with sam- rris spp.(Yogel 1974; K. S. Bawa, S. L. Buchmann,B. aroid fruits. Byrsonima and a few of its closest relatives Gates,pers. comm.). The bee alightson the , ori- have lost (or never had?) such nectaries,and the only entingwith her headtoward the flagpetal and graspingits glands on the plant are the calyx glands. claw with her mandibles.Reaching-between the clawed Byrsonima is a very large ( I 30 speciesor more), with her front two pair of legs, she scrapesthe probablythe largestin the Malpighiaceae.It hasachieved glands,depositing the oil in specialstructures on her hind a level of diversity and distribution far greater than its legs. The oil is mixed with pollen to make food for her more primitive relatives in the subfamily Byrson- larvae;the adult bee herselffeeds on sugarynectars ob- imoideae.This seemslikely to be relatedprimarily to its tained from other speciesof flowering (Vogel evolution of bird-dispersedfruits, whereasmost mem- 1974). Some species of Byrsonima have eglandular bers of the subfamily have little or no adaptation for flowers, either throughoutthe speciesor only in certain efficient dispersal.Two other generaof Malpighiaceae, individuals or populations. It would be interesting to and , have evolved bird-dispersed study the pollination biology of such species,especially fruits. They are not closely related to Byrsonima or to in populationswith both glandularand eglandularplants, each other, and fleshy fruits very probably evolved three as in B. chrysophylla on the campusof INPA in Manaus. times in parallel in this family (Anderson 1978). Al- There are several hypothesesthat could explain such though some species of Byrsonima inhabit wet forests, polymorphism,some of them tied to the behaviorof the the great majority grow in savannas, where they vary oil bees. In this connectionit is important to note that from fairly large trees down to twiggy with Bawa (1974) found B. crassifoliato be self-compatible. subterraneanstems, forming a matlike covering on ter- Also seeAnderson (1980). mite mounds in cenffal Brazil.

203 PLANTS *

Anderson,W R. 1978.Byrsonimoideae: A new subfam- ily of the Malpighiaceae.Leandra 7;5-18. 1979. Floral conservatismin NeotropicalMal- pighiaceae.Biotropica I l:219_23. 1980. Cryptic self-fertilization in the Mal- pighiaceae.Science 207 :892-93. Bawa,K. S.1974. Breedingsystems of treespecies of a Iowland tropical community.Ev olution 28:85-92. Vogel, S. 1974. Olblumen und cilsammelndeBienen. Ziop. subtrop.Pflanzenwelt 7 :l-547 .