nearly throughout the tropics, inchiding the Old 

 World. 



Related Species 



All other native tree species of each genus are 

 mentioned, usually under the first species of the 

 genus or sometimes under a similar one, to aid in 

 further identification. Preferred Spanish and 

 English names are given where known, though 

 some species probably bear the same names or onlj' 

 those of the genus. Distinguishing characters for 

 comparing related species with those figured have 

 been compiled largely from Britten and Wilson 

 (5). Distribution is given by islands. In the two 

 largest tree genera, Evgenia with 2.5 native species 

 and Miconia with 16, the other species have merely 

 been listed. Keys for identification in these as 

 well as the other genera were published by Britten 

 and Wilson also. 



Where no related species are mentioned, all na- 

 tive tree species of the genus, usually only one or 

 two, are illustrated. However, introduced tree 

 species, shrubs, and herbs have not been cited. Of 

 course, some entire genera and 20 families, mostly 

 with few species of small, less important trees, 

 have been omitted. 



EXPLANATION OF BOTANICAL 

 TERMS 



Botanical descriptions for the classification and 

 identification on trees are based principally on dif- 

 ferences of leaves, flowers, and fniits, and their 

 parts, such as pre.sence or absence, number, ar- 

 rangement, shape, size, and union or separation. 

 To record these details, systematic botanists, or 

 plant taxonomists, have a special terminology of 

 technical words derived from Latin and Greek, 

 defined and illustrated in botany textbooks and 

 floras. In this book, nontechnical terms have been 

 used wherever possible, though some technical 

 terms have been inserted in parenthesis or adopted 

 where there was no clearer equivalent. Principal 

 terms used in this book are explained here, while 

 manj^ are illustrated by the drawings. Thus, it 

 has seemed unnecessary in include a glossary. 



Leaves 



These flat, green organs serving for food manu- 

 facture are very useful in the identification of trees, 

 usually present in quantities and of large size. 

 The point on a twig where 1 or more leavefi are at- 

 (aclied is the node. In arrangement on the twig, 

 leaves attached singly or 1 at a node are aJternnte^ 

 leaves borne in pairs or 2 at a node are opposite, 

 and leaves inserted 3 or more at a node are whorled. 

 Parts of a leaf are the leafstalk or petiole and the 

 flat expanded part or bhide. In some species there 

 are 2 (or 1) scales at the base of a leaf called 

 ifipiilefi, usually shedding early but sometimes 

 forming distinctive buds at the end of a twig. 



In number of blades a leaf with 1 blade is simple., 



while a compound leaf has usually several blades 

 (rarely only 2) called leaflets, which may or may 

 not have stalks. A leaflet is distinguished from a 

 simple leaf by the absence of a bud at the base and 

 by the shedding of the axis. Also, leaflets are in 

 2 rows along the axi.s, while simple leaves may be 

 similar but more often not in 2 rows on the twig. 

 Compound leaves are pinnate or pinnately com- 

 pound when the leaflets ai-e inserted along a com- 

 mon axis and fl'/t/Zfr/Yf (or palmate) when attached 

 together at the end of the petiole. If the axis has 

 liranches a leaf may be twice pinnate or hipinnate 

 or if branched again the leaf is three times pinnate 

 or triplnnrife. Pinnate leaves may be even pinnate 

 when the leaflets are paired and end in a pair, and 

 odd pinnate wlien ending in a single leaflet. 



Several terms describe the shape of leaf blades. 

 A linear leaf has a narrow grasslike blade with 

 edges parallel, and an ohlong leaf is broader but 

 with edges also nearly parallel. A lance-shaped or 

 lanceolate leaf has the form of a lance, several 

 times longer than broad, pointed at apex or tip 

 end, and broadest near base, while the reverse 

 shape is oblanceolate. An ovate leaf has an oval 

 shape broadest toward the base, more or less as in 

 an egg, while an ohovate leaf is the reverse, 

 broadest toward apex. An elliptic leaf has an oval 

 shape but broadest in the center. A circular leaf 

 has the blade more or less in form of a circle, while 

 a spafulate leaf is spoon-shaped. 



As to margin or edge a leaf blade may be 

 toothed, lobed, without teeth, or rolled under. The 

 a])ex and base of a leaf blade may be long-pointed, 

 short-pointed, or rounded, or the base heart- 

 siiaped, if with two rounded lobes. 



In venation or arrangement of the veins a leaf 

 blade may be parallel-veined, if the veins are 

 closely placed side by side or parallel; pinnate- 

 reined, with a single main vein or midrib and lat- 

 eral veins on both sides somewhat as in a feather; 

 or palmate-veined, when several main veins arise 

 at the base and spread like fingers in a hand. 



Flower Clusters 



The grouping of flowers and fruits in clusters 

 (inflorescences) and their location and arrange- 

 ment often provide characters useful in identifica- 

 tion of trees. A flower cluster is terminal when it 

 is at the apex or end of a twig and lateral when 

 borne at the base of a leaf or on the side of a twig. 

 The flowers may be produced singly, one by one. 

 A spike is a flower cluster with elongated axis 

 bearing stalkless flowers, while a raceme has an 

 elongated axis with stalked flowers, and a panicle 

 is a compound raceme with branched axis. An 

 umbel has flowers on spreading stalks of equal 

 length attached together at the apex of a larger 

 stalk somewhat like an umbrella. A head bears 

 stalkless flowers on the broad disklike apex of the 

 axis. In a cyme the flower clu.ster is definite, with 

 the main axis ending in the first flower and with 

 other flowers borne on branches below. 



