POLYGALACE^. 223 



are subterranean or next the ground, often of simpler and 

 less irregular structure and with short styles, which are 

 fertilized in the bud, in the manner of Viola, and of Im- 

 patiens (Plate 153, page 133), &c. Pedicels commonly 

 articulated, bracteate, and mostly bibractcolate at or near 

 the base. 



Etymology. A name applied to this genus by the earliest botanists, 

 compounded of iroXvs, much, and yaXa, milk; from the prevalent idea 

 that these plants possessed the property of increasing the lacteal secre- 

 tion. 



Geographical Distribution, Properties, &c., are considered under 

 the order. 



Note. This large genus, comprising two or three hundred species, was 

 arranged by De Candolle in eight sections, which now greatly need entire 

 revision. Two of the more distinct forms which occur in the United States 

 are here chosen for illustration. The hypogeeous fertile flowers of P. pau- 

 cifolia which we examined exhibited the corolla reduced to the keel-petal 

 alone, to the margins of which the two phalanges of three stamens each 

 directly adhere. 



PLATE 183. PoLYGALA Senega, Linn.; — a plant, of the natural size 

 (Northern New York). 



1. Diagram of the flower. 



2. Vertical section of a flower, magnified, dividing the ovary and display- 



ing the ovules. 



3. The calyx spread out and magnified, seen from underneath. 



4. Inside view of the corolla and stamens, spread out and magnified, the 



two phalanges united nearly to the summit. 



5. An anther, with the distinct portion of the filament, magnified. 



6. The pistil, seen laterally, with the receptacle, magnified. 



7. Capsule, w-ith the persistent calyx, magnified. 



8. A magnified seed, showing its raphe and the two-horned caruncle. 



9. A vertical section of the same, displaying the embryo. 



10. Transverse section of the same and of the cotyledons. 



11. The embryo detached (inverted), the large cotyledons separated, mag- 



nified. 



12. Seed of PoLYGALA CKVcik-r k, Linn. ; — magnified. 



13. Transverse section of the same. (Tlie albumen in this species is of 



equal thickness all round the embryo ; but the engraver has wrong- 

 ly represented it as thinner at the edges of the cotyledons, as is in- 

 deed the case in P. Senega.) 



