SECTION 10. J 



PISTILS. 



109 



tiguous margius of two pistil-leaves grown together. There is every grada- 

 tiou between this aud the three-celled ovary with the placenta} in the axis, 

 even in the same genus, someiimes even in diflereut stages iu the same 

 pistil (Fig. 335, 33G). 



§ 2. GYMNOSPERMOUS GYN(ECIUM. 



313. The ordinary pistil has a closed ovary, and accordingly the pollen 

 can act upon the contained ovules only indirectly, through the stigma. 

 This is expressed iu a term of Greek derivation, viz. : — 



Aiiffioi^permous, meaning thaL the seeds are borne in a sac or closed 

 vessel. The counterpart term is 



Gymnospermous, meaning naked-seeded. Tliis kind of pistil, or gynoe- 

 cium, the simplest of all, yet tlie most j)eculiar, characterizes the Pine 

 family and its relatives. 



314. While the ordinary simple pistil is conceived by the botanist to 

 be a leaf rolled together into a closed pod (306), those of the 

 Pine, Larch (Pig. 337), Cedar, and Arbor-Vitai (Fig. 338, 

 339) are open leaves, in the form of scales, each bearing two 

 or more ovules on tlie inner face, next the base. At tlie time 



^■'^ of blossoming, these pistil-leaves of the young cone diverge, 



and the pollen, so abundantly shed from the stam- 

 iuate blossoms, falls directly upon the exposed 

 ovules. Afterward the scales close over each 

 other until the seeds are ripe. Tlien ihey sepa- 

 rate that the seeds may be siied. As the pollen 

 acts directly on the ovules, such pistil (or organ 

 acting as pistil) has no stigma- ' 



315. In the Yew, and in Torreya and Giiigko, 

 the gynoecium is reduced to extremcst simplicity, 

 that is, to a naked ovule, without any visible 

 carpel. 



316. In Cycas the large naked ovules are borne 

 on the margins or lobes of an obvious open leaf 

 plants have other peculiarities, also distinguishing 

 Angiospeumous plants. 



All Gymnospermous 

 them, as a class, from 



Fig. 337. A pistil, tliat is, a scale of the cone, of a Larch, at tlic time of flower- 

 ing; inside view, showing its pair of naked ovules. 



Fig. 338. Branchlet of the American Arbor- Vitje, considerably larger thar. in 

 nature, terminated by its pistillate flowers, each consisting of a single scale (an 

 open pistil), together forming a small cone. 



Fig. 339. One of the scales or carpels of the last, removed and more enlarged, 

 the inside exposed to view, showing a pair of ovules on its base- 



