amphitropous ovule
Definition
Noun: A type of ovule (the structure in seed plants that develops into a seed after fertilization) that is partially inverted. Specifically, it is bent or curved along its axis so that the body of the ovule is at a 90-degree angle relative to its stalk (funicle), and the micropyle (the opening for pollen entry) is positioned near the base.
Usage
This is a highly specialized botanical term used to describe the orientation and morphology of an ovule within a plant's ovary. It is used in scientific descriptions, classifications, and botanical texts. - The genus is characterized by having amphitropous ovules. - Under the microscope, the amphitropous ovule was clearly visible, bent at a right angle to its funicle.
Advanced Usage
- Classification Context: The term is used in contrast to other ovule types like orthotropous (straight), anatropous (completely inverted), and campylotropous (curved). It describes a specific developmental and structural adaptation.
- Phylogenetic Studies: The presence of amphitropous ovules can be a taxonomic character used to differentiate plant families or genera.
Variants and Related Words
- Ovule (n): The general structure that becomes a seed.
- Anatropous ovule (n): An ovule that is completely inverted.
- Campylotropous ovule (n): An ovule that is curved so the micropyle is near the funicle, but not at a precise 90-degree angle.
- Orthotropous ovule (n): An ovule that is straight and upright.
Synonyms
- Partially inverted ovule (descriptive synonym)
Related Terms and Concepts
- Funicle (n): The stalk that attaches the ovule to the placenta of the ovary.
- Micropyle (n): The small opening in the integuments of an ovule through which the pollen tube usually enters.
- Chalaza (n): The base of an ovule, opposite the micropyle.
Noun
-
a partly inverted ovule turned back 90 degrees on its stalk
