GRASS FAMILY (GRAMINEAE) 



3. Bambu, common bamboo 



Bamboos, giant introduced evergreen grasses 

 with clustered, jointed hollow stems and feathery 

 foliage, are so dift'erent that they are not likely to 

 be confused with any other trees. Perhaps they 

 are not trees at all, because they grow in clumps of 

 several stems, like many shrubs, and do not have 

 a single trunk from the base. Their large treelike 

 size and usefulness justify their inclusion here. 



The first and l)y far the commonest of about 30 

 exotic species of bamboo, this species was intro- 

 duced into Puerto Rico more than a century ago 

 and thus is sometimes incorrectly called native 

 bamboo. It is diflicult to distinguish between 

 some of the different species, as the flowers needed 

 for positive identification are rarely produced. 

 However, as a group bamboos are easily recog- 

 nized by: (1) clusters of several to many slender, 

 tapering, slightly curved stems 2—1 inches in diam- 

 eter, dark green to orange, with swollen rings or 

 joints 8-18 inches apart; (2) several verj^ slender 

 branches spreading horizontally and regularly at 

 the joints; and (3) grass leaves in 2 rows, consist- 

 ing of basal sheath around the slender twig and 

 long-pointed blade with many lateral veins paral- 

 lel with midrib. 



In this species stems (culms) attain 30-.50 feet 

 in height and toward the top diverge from the 

 center. The smooth surface, green to dark green, 

 becomes orange or yellow in age. From a distance 

 the plant appears like a clump of giant ferns. 

 The slender lateral branches, about 14 inch in di- 

 ameter, are nearly horizontal and bear wirelike 

 yellow-green twigs. Spines are absent in this 

 species. A horticultural variety has variegated 

 stems with yellow and green vertical stripes. 



The light green leaf sheaths are li/^-2i4 inches 

 long, closely fitting the twig. Blades are 6-10 

 inches long and %-l% inches wide, or as short as 

 2 inches at base of twig, with rough edges, long- 

 pointed at apex and short -pointed where narrowed 

 and jointed into sheath. The upper surface of the 

 flat thin blade is green and slightly shiny, the 

 lower surface pale blue green. 



The large bamboos bloom only once. Generally, 

 after a long period of many years of growth, many 

 plants growing together flower simultaneously, 

 produce seeds, and then die. Like most other 

 grasses, bamboos have inconspicuous flowers 

 usually light brown or straw colored. The flower 

 cluster (panicle) of this species is composed of 

 slender branches bearing bracted clusters of 3-15 

 or more stalkless spikelets i/^-% inch long, oblong 

 and pointed, each with several to many flowers 

 (florets) about % inch long. The flower has 

 2 narrow scales, 6 stamens with purple protruding 

 anthers, and pistil, producing an oblong grain. 



Not divided into bark and wood, the stem is hol- 

 low except at the nodes, lightweight, hard, and 



Bambusa vulgaris Schrad.* 



strong. It completes its height growth from the 

 clustered roots at base in about 3 months, elongat- 

 ing very rapidly as much as 8 inches daily. Nor 

 does it expand in diameter after it is first formed. 



A new growing shoot at the outside of a clump 

 is readily distinguished by the absence of branches 

 and by the presence at each node or joint of a large 

 leaf, with triangular spreading blade. These 

 clasping leaves along the main axis have a very 

 large gray-green sheath 6-12 inches long, extend- 

 ing nearly to the next node and bearing many 

 brown needlelike hairs that stick in the flesh when 

 touched, and a short triangular pointed yellow- 

 green blade 2-3 inches long and broad, also with a 

 few brown hairs. Toward the apex of the elongat- 

 ing stem the leaves are closer together and over- 

 lapping. 



Bamboos of this and other species have many 

 uses besides ornament and pasture shade. Their 

 masses of intertwining roots and accumulations of 

 leaf litter check erosion on roadside banks and 

 slopes. Poles of various kinds for construction, 

 fences, fenceposts, ladders, tool handles, flagpoles, 

 and stakes are easily made from bamboo. The 

 stems will serve as temporary water pipes after 

 opening them on one side at each node and remov- 

 ing the partitions. Short pieces are used as pots 

 for seedlings to be transplanted later. Bamboo 

 boai'ds can be prepared by slitting, splitting, and 

 spreading ojien the stems, and the split pieces 

 woven into baskets. Bamboo stems have been uti- 

 lized in the manufacture of various articles, in- 

 cluding furniture, lattices, fishing rods, picture 

 frames, lampshades, mats, and flower vases. This 

 is not the best bamboo because the stems are not 

 resistant to damage by the bamboo powder-post 

 beetle [Dhodermminutiis (F.) ) as are those of 

 certain more recently introduced species. Also 

 very susceptible to attack by dry-wood termites. 



With outer scales removed, the tender growing 

 tips of bamboo shoots can be eaten by boiling 

 about one-half hour and changing the water once 

 or twice to remove any bitter taste. There is no 

 distinct flavor except "for a slight suggestion of 

 young corn. Bamboo shoots are prepared in meat 

 stews, salads, and other ways. 



This species is commonly planted throughout 

 Puerto Rico in moist soil, .such as along streams and 

 roadsides and for ornament because of the attrac- 

 tive feathery foliage. Also in St. Croix, St. 

 Thomas, and St. John. Spreading from cultiva- 

 tion but not naturalized as it does not grow ordi- 

 narily from seeds. However, in the Lesser Antilles 

 natural vegetative propagation by breaking and 

 rooting of the fragile short branches occurs. 



♦Exotic, or introduced. Species ( or families ) with scien- 

 tific names followed by an asterisk are not native in Puerto 

 Rico and the Virgin Islands. 



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