310 SCIENTIFIC AND APPLIED PHARMACOGNOSY 



or less resinous; inner surface dark red or reddish-brown, with one 

 or two circles of collateral fibrovascular bundles separated by broad 

 medullary rays, pith large; odor slight; taste strongly astringent. 



Inner Structure. A thick stratum of reddish-brown cork cells; 

 the cortical -parenchyma, containing either starch, resin or tannin, 

 the walls being colored reddish-brown; fibrovascular bundles in two 

 circles (a), those near the cambium ring having on the exterior small 

 groups of collapsed sieve cells surrounded by parenchyma having 

 lattice-like thickenings of the wall; and (&), an inner circle of bundles 

 composed of whitish wood wedges separated by broad parenchyma- 

 like medullary rays; wood wedges composed of porous tracheae and 

 wood fibers, among which are distributed the wood parenchyma 

 containing a reddish-brown amorphous tannin content: pith com- 

 posed of starch-bearing, nearly isodiametric parenchyma cells con- 

 taining rosette aggregates of calcium oxalate. In young rhizomes 

 starch grains preponderate, being replaced in older and more fleshy 

 rhizomes by resin. 



Constituents. Tannic acid from 18 to 30 per cent; tormentilla 

 red, a product of decomposition of the tannin; ellagic acid, a trace 

 of volatile oil and a resin. 



LEGUMINOS^I, OR PULSE FAMILY 



The second largest family of plants, comprising almost 8000 

 species. They are widely distributed and are most numerous in 

 the tropical and sub-tropical regions. They exhibit a great range 

 of habit from creeping annual herbs to climbing shrubs, and vary 

 from delicate herbs to very tall trees. They are characterized by 

 alternate, stipulate, usually compound leaves; papilionaceous or 

 sometimes regular flowers, having usually monadelphous or diadel- 

 phous stamens, and a single free pistil, becoming in fruit a legume. 

 It is by reason of the latter feature that the family receives its 

 name. 



As to be expected in a large family like this, there are certain 

 distinct morphological characters which admit of dividing it into 

 smaller groups. This is done by some botanists and the groups 

 given the rank of families. These are the following : 1, Papilionaceae, 

 those plants which produce irregular, papilionaceous flowers. They 

 are also characterized in having calcium oxalate in the form of sty- 

 loids or small rod-like crystals, being not infrequently inserted in the 

 thickenings of the cell walls. Tannin-sacs, secretion cells, resin 

 canals, lysigenous gum canals and other secretory cavities occur 



