JUNGLE PLANT 471 



to gallotannic acid distributed throughout the parenchyma. Small 

 groups of bast fibers are occasionally found in the pericycle. The 

 fibrovascular bundles are bi-collateral, frequently having an intra- 

 xylary development of leptome. The tracheae have simple pores, 

 except when in contact with the wood parenchyma, when bordered 

 pores are developed. The wood fibers possess bordered pores and 

 the medullary rays are narrow. Calcium oxalate is usually secreted 

 in the form of rosette aggregates giving rise to translucent dots in 

 the leaves. In the stems the calcium oxalate is in the form of crystal 

 fibers accompanying the bast fibers. The non-glandular hairs are 

 unicellular or consist of two horizontally placed cells connected at 

 their bases. The glandular hairs possess either long or short stalks. 



COMBRETUM. Jungle Plant. The leaves of Combretum sun- 

 daicum (Fam. Combretacea3), a woody climber, indigenous to 

 Sumatra and used to some extent in the treatment of the opium habit, 

 thereby receiving the name of " anti-opium plant." 



Description. More or less crumpled and mixed with rather large 

 stem portions; leaves broadly elliptical or ovate, short petiolate, 

 from 8 to 15 cm. in length and 5 to 7 cm. in breadth, summit acute, or 

 acuminate, base rounded, margin entire or slightly wavy, upper 

 surface light to dark greenish-brown, lower surface somewhat lighter 

 in color, reticulate and marked by a distinct midrib and veins of the 

 first order, the latter diverging at an angle of about 50 and uniting 

 with each other along the margin, coriaceous; petiole from 7 to 

 15 mm. in length, having a shallow groove on the ventral surface; 

 odor slight; taste slightly bitter and acrid. 



Stems from 6 to 15 cm. in length and from 3 to 15 mm. in diameter, 

 light brown or light reddish-brown, longitudinally striate, waxy, 

 sometimes with long, grayish patches of cork, branches opposite; 

 fracture short, fibrous, internally bark thin, light brown, wood large, 

 porous and a small pith. 



IM& Inner Structure. Epidermal layer of upper surface of rectangular 

 or tabular cells, having very thick, colorless walls and each usually 

 containing a large nucleus; palisade layer of two or three rows of 

 rather short, narrow cells; loose mesophyll of 8 to 12 rows of thick- 

 walled cells having large intercellular spaces and among which are 

 distributed the fibrovascular bundles and cells containing calcium 

 oxalate; epidermal cells of dorsal surface resembling those of the 

 ventral surface; fibrovascular bundle of the veins, hemispherical in 

 shape, consisting of a large crescent-shaped xylem, having in the 

 sinus as well as at the periphery the strands of leptome and sur- 

 rounded by a nearly continuous ring of narrow stereome or scleren- 



