GLOSSARY 353 



Palmate (pertaining to the hand). Radiating like the fingers ; said 

 of the veins or divisions of some leaves. 



Panicle (a tuft). A loose and irregularly branching flower cluster, as 

 in many grasses. 



Pappus (down). The modified calyx of the composites. 



Paraphysis (accompanying organs) ; pi. paraphyses. Sterile bodies, 

 usually hairs, which are found mingled with the reproductive organs of 

 various lower plants. 



Parasite. An organism that obtains its food from the living tissues 

 or the secretions of other organisms. 



Parenchyma. Ordinary or typical cellular tissue, i.e. of thin-walled 

 cells nearly equal in all their dimensions. 



Parthenogenesis. The formation, without fertilization, of a spore which 

 is functionally the same as a sexual spore. In general it means that the fe- 

 male gamete becomes a spore directly, and may grow without fertilization. 



Pedicel (a little foot). The stalk upon which a structure is borne. 



Peduncle (a little foot). The flower stalk. 



Pentacyclic (five cycles). Applied to flowers whose four kinds of 

 floral organs are in five cycles. 



Perianth (around the flower). The floral envelopes or leaves of a 

 flower, taken collectively ; and an analogous envelope of the sporogo- 

 nium of certain liverworts. 



Periblem (a cloak). A name given to that part of the meristem at 

 the growing point of the plant axis, which lies just beneath the epider- 

 mis and develops into the cortex. 



Pericambium (surrounding growing tissue). In roots, the external 

 layer of the fibrovascular cylinder. 



Pericarp (around the fruit). The wall of the ovary, developed into a 

 part of the fruit. 



Perigynous (around the ovary). Applied to those flowers whose sta- 

 mens and perianth arise from around the wall of the ovary. 



Peristome (around the mouth). In mosses, usually bristle-like or 

 tooth-like structures surrounding the orifice of the capsule. 



Petal (a leaf). A corolla leaf. 



Petiole (a little foot). The stalk of a leaf. 



Phanerogamia (evident marriage). A primary division (the highest) 

 of plants, named, from their mode of reproduction, the seed-producing 

 plants. Phanerogam is the English equivalent. 



Phloem (the inner bark). The bark or bast portion of a fibrovas- 

 cular bundle. 



Photosynthesis (light construction). The name applied to the process 

 by which chloroplasts under the influence of sunlight manufacture such 

 carbohydrates as sugar and starch from water and carbon dioxide. 



