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five green sepals of, the calyx are united somewhat unequally so 
that the teeth at the top of the tube are thrown into two sets, 
the anterior containing three and the posterior two. The corolla 
has five petals, the posterior (standard or vexillum) being larger 
and enclosing the others in the bud, but expanding and turning 
back at maturity. Interior to the two lateral petals lie the two 
lower ones and these last cohere along their anterior edges form- 
Fig. .81. — 1, Cross section of young stem at time of beginning of cambial 
activity, p, pith ; x, xylem ; pin, phloem ; c, cambium. 2, Portion of cross 
section of older stem, rb, region of bast. 
ing the carina which encloses the stamens and pistil (5, figure 
83). The stamens, ten in number, are diadelphous, the one next 
the vexillum being free to the base while the rest are united 
for three-fifths of their length. In the bud the anthers occur 
in two sets or cycles, one above the other (6, figure 83), but at 
maturity the lengthening of the filaments has brought them to 
