ASCIDIA, STIPULES, AND BRACTS. 



93 



9. Quinate, when there are five leaflets radiating from the 

 same point of the petiole, as in Potcntilla argcntea. 



10. Septinate, when there are seven leaves from the same 

 point in the petiole, and so on. 



242. With regard to insertion, the leaf is said to be 



1. Amplexicaul, when its base snn-onnds or clasps the stem. 



FIG. 33. — Modes of insertion. 



2. Perfoliate, when the base lobes of an amplexicaul leaf are 

 united together, so that the stem appears to pass through the 

 leaf 



3. Decurrent, when the base lobes of the leaf grow to the 

 stem below the point of insertion, so that the leaf seems to run 

 downwards (Lat. decurro). 



4. Connate, when the bases of two opposite leaves are united. 



5. Stellate, verticillate, or whorled, "when several leaves are 

 arranged around the stem at the same node. 



243. It is often found necessary, in the description of a plant, to combine two 

 or more of the terms above mentioned, to express some intermediate figure or 

 quality ; thus ovate-lanceolate, signifying between ovate and lanceolate, &c. 



a. The Latin preposition sub (under), prefixed to a descriptive term, denotes 

 the quality which the tenn expresses, in a lower degree, as subsessile, neaiiy ses- 

 sile, subsetrate, somewhat serrate, &c. ^ 



§9. ASCIDIA, STIPULES, AND BRACTS. 



244. In the teazel (Dipsacus) of our own fields, and in the Tillandsia, or wild 

 pine of South America, there are hollows at the point of union between the leaf- 

 stalk and the stem, capable of holding a considerable amount of Avater. The 

 midrib and petiole of the leaves of the Arum, also, are channeled out in such a 

 manner as to convey water to the axil. 



245. But the most remarkable of all leaves are those which are hollowed out 

 into the fonn of pitchers, called ascidia. 



a. In the SaiTacenia, a plant common in our OAvn peat-bogs, these pitchers are 

 evidently formed by the very deep channeling of the petiole, and the uniting 

 together of the involute edges of its winged margin so as to form a complete 

 vase, with a broad expansion at the top, which may be regarded as the true leaf. 



