106 



SIMPLE PISTILS. 



[SECTION 10. 



305. Carpels. It is convenient to have a name for each flower-leaf of 

 the gyuceciura ; so it is called a Carpel, in Latin Carpellum or Carpidium. 

 A simple pistil is a carpel. Each component flower-leaf of a compound 

 pistil is likewise a carpel. When a flower has two or more pistils, these 

 of course are simple pistils, that is, separate carpels or pistil-leaves. There 

 may be only a single simple pistil to the flower, as in a Pea or Cherry 

 blossom (Fig. 271) ; there may be two such, as iu many Saxifrages ; or 

 many, as in the Strawberry. More commonly the single pistil in the 

 centre of a blossom is a compound one. Then there is seldom much 

 difficulty in ascertaining the number of carpels or pLstil-leaves that com- 

 pose it. 



306. The Simple Pistil, ™wed morphologically, answers to a leaf- 

 blade with margins incurved and united where they meet, so forming a 

 closed case or pod (the ovary), and bearing ovules at the suture or junction 

 of these margins : a tapering upper portion with margins similarly inroUed, 

 is supposed to form the style ; and these same margins, exposed at the tip 

 or for a portion of the length, become the stigma. Compare, under this 

 view, the three accompanying flgures. 



307. So a simple pistil should have a one-celled ovary, only one line of 



attachment for the ovules, a single style, 

 and a single stigma. Certain variations 

 from this normal condition which some- 

 times occur do not invalidate this mor- 

 phological conception. For instance, the 

 stigma may become two-lobed or two- 

 ridged, because it consists of two leaf- 

 margins, as Fig. 324 shows; it may 

 become 2-looellate by the turning or grow- 

 ing inward of one of the sutures, so as to 

 divide the cavity. 



308. There are two or three terms which primarily relate to the parts 

 of a simple pistil or carpel, and are thence carried on to the compound 

 pistil, viz. : — 



Ventral Suture, the line which answers to the united margins of the 

 carpel-leaf, therefore naturally called a suture or seam, and the ventral 

 or inner one, because in the circle of carpel-leaves it looks inward or to the 

 centre of the flower. 



DonSA-L Suture is the line down the back of the carpel, answeriug to 



Fig. 323. An inrolled small leaf, such as in double-flowered Cherry blossoms is 

 often seen to occupy the place of a pistil. 



Fig. 324. A simple pistil (of Isopyrum), with ovary cut across ; the inner (ven- 

 tral) face turned toward the eye : the ovules seem to he borne on the ventral suture, 

 answering to leaf-margins : the stigma above seen also to answer to leaf-margins. 



Fig. 325. Port or simple pistil of Caltha or Marsh-Marigold, which has opened, 

 and shed its seeds. 



