GLOSSARY Vli 



plur-anmial. A plant of a tropical or semi-tropical climate that is 

 annual in a colder country only because it is killed by frost; as 

 tomato, castor-bean. 

 pollen. The dust or grains contained in the anther and which, falling 



on the stigma, grows and fertilizes the forming ovules. 



pollination. The transfer of pollen from the anther to the stigma. 



The transfer may be accomplished by wind, insects, birds, water 



(in the case of water plants), or by the natural falling of the pollen. 



polypetaloas (" many-petaled"). Said of a corolla with the petals not 



united. 

 polysepalous (" raany-sepaled "). Said of a calyx with sepals not united. 

 poi7te. An apple-like or pear-like or quince-Uke fruit, with a five-car- 



peled or ten-carpeled " core." 

 proterandrous. Said of a flower when the anthers mature in advance 



of the pistils in the same flower. 

 proterogynoiis. Said of a flower when its pistils mature before its 



anthers. 

 prothallus (" first thallus "). The minute leaf-like body or organ pro- 

 duced by the germination of a spore, in ferns and allied plants. 

 It bears the sex organs. 

 protoplasm. The living matter in plants. It is the living part of the 



cells, usually in a semi-fluid, translucent state. 

 pseud-annual. A plant that is apparently annual, but which is carried 



over winter by a bulb, tuber, or similar body ; as potato, onion. 

 pyxis. A dry fruit or capsule in which the top comes off', like a cover 



to a jar. 

 raceme. A simple (unbranched) cluster in which the flowers are on 



short pedicels and open from the base upwards. 

 raphe. A ridge or elevation on some seeds caused by the seed-stalk 



and seed-coats growing together. 

 ray. The elongated corolla-limb of some members of the Compositas 



family. 

 receptive. Said of a stigma when it is " ripe " or ready to receive the 



pollen. 

 regular flowers are those in which all the members of each series (as 

 all the sepals, or all the petals, or all the stamens) are like each 

 other in shape, size, and color. 

 reinforced. See accessory fruits, 

 respiration. Breathing; manifest by oxygen taken in and carbon 



dioxid given off'. 

 rhizome. A rootstock ; an underground root-like stem. It has joints, 

 usually scales representing leaves, and is often thick and fleshy. 



