GLOSSARY 349 
Epiphyte. A plant which grows upon other plants. 
Fertilization. The act of uniting an egg and a sperm. 
Fibrovascular bundles (fiber vessels). The strands that make up the 
framework of higher plants. 
Filament (a thread). The stalk of the stamen that supports the 
anther; also the individual threads of algee or fungi. 
Filiform. Thread-like. 
Fission (splitting). Cell division resulting in division into halves. 
Fleshy. Thick, succulent. 
Flowering glume. In grasses, the bract that subtends each flower, 
sometimes called lower palet. 
Formation. An ecological group. It signifies a well-defined assem- 
blage of plants characteristic of some kind of station. 
Frond (a leaf). A name given to the leaf of ferns. 
Fruit. The ripened ovary and its contents. 
Funiculus (a slender rope). The stalk of an ovule or seed. 
Gametangium (gamete vessel). The specialized organ for production 
of gametes. 
Gamete. A reproductive cell which ordinarily becomes functional 
only upon union with another. As a result of this union a sexual spore 
is formed. 
Gametophyte (gamete plant). The sexual stage of an alternating plant. 
Gemma (a bud); pl. gemmz. In bryophytes, many-celled buds special- 
jzed for vegetative propagation. 
Generative cell. The cell within the male gametophyte of spermato- 
phytes (usually within the microspore wall) which divides to form the 
two male cells. 
Geotropism (turning toward the earth). The tendency of organs or 
portions of organs to go downward. 
Glaucous (pale green, gray). Whitened with a bloom, like that on 
a cabbage leaf. 
Glume (a husk). A chaff-like bract belonging to the inflorescence of 
grasses; the outer glumes subtend the spikelet; the flowering glume 
is the bract of the flower. 
Gluten (glue). A term used for the gluelike products of plants, 
especially of seeds. 
Grain. A seed-like fruit, like those of grasses, with pericarp grown 
fast to the seed; also any small, rounded body, as of starch. 
Growing point. The group of meristem cells at the growing tip of 
an organ, from which the various tissues arise. 
Guard cells. The cells (usually two) which open and close a stoma. 
Gymnosperms (naked seeds). One of the two groups of spermato- 
phytes (seed plants). 
