862 WEED FLORA OF IOWA 



GLOSSARY. 



BY HARRIETTE S. KELLOGG. 



Accumbent. Lying against, as when the edges of the cotyledon 

 lie against the caulicle or radicle. 



Achene. A dry, hard. 1-celled, 1-seeded, indehiscent fruit. 



Acuminate. Tapering somewhat gradually to a point. 



Acute. Ending in a sharp angle, not prolonged. 



Aerial roots. Those appearing on the stem above ground; may 

 be brace roots as in corn, or clinging roots as in ivy. 



Albumen. Nutritive material in seeds accompanying the 

 embryo. 



Aleurone grains. Protein grains replacing albumen in a few oily 

 seeds, and starch in others. 



Aleurone layer. Outer layer of the endosperm next to the peri- 

 sperm. 



Alternate (leaves). One at a node, not opposite; (flowers) parts 

 of one whorl opposite to intervals of next. 



Anatropous. Inverted and straight. 



Angiosperms. Higher seed plants. 



Angium. Case for pollen grains. 



Annual. A plant that performs its life cycle from germination 

 to matured seed in one season. 



Annual (Winter). A plant that germinates in the fall, grows 

 until frost; but blooms and matures seed the following spring. 



Anther. The part of the stamen which contains the pollen. 



Apetalous. Without petals. 



Apex. Is opposite to point of attachment. 



Appressed. Lying flat against. 



Arachnoid. Cobwebby; covered with tangled hairs, fewer and 

 longer than when tomentose. 



Arrow-shaped. See Sagittate. 



Ascending. Rising obliquely or curving upward. 



Auricle. An ear-shaped appendage. 



Awn. An appendage composed of bristles. 



Axil. The upper angle formed between the leaf and stem. 



Axis. The central line of any organ or support of a group of 

 organs. 



Axillary. In the axil. 



Barbed. With ridged points or short awns usually reflexed. 



