Definitions of hermaphroditism, dioecious and monoecious?

Question

What is the difference between these terms "monoecious","Hermaphrodite". my lecturer says hermaphrodite is a zoological term and monoecious is botanical term, but in contrary to it, in my textbook both of these terms are used both botany and zoology.

So what is the actual difference?

Answer 1

Below are definitions that I've seen; there may be less strict definitions under which monoecy (the noun form of 'monoecious'). and hermaphroditism would be the same thing.

Dioecious: Although rarely used for animals, one could say that human are dioecious because each individual produces only one type of gamete. In a dioecious species, some individuals are males and others are females.

Monoecious: In monoecious plants, individuals carry both males and female flowers but not flowers that can produce both female and male gametes.

Hermaphrodite: Hermaphroditic plants have flowers that can produce both male and female gametes.

Then, there are many other fancy terms such as dichogamous, gynomonoecious, subandroecious, heterostyly or androgynomonoecious! Plant mating systems are fantastically diverse and complex!

More information

Some of these terms are defined in The Evolution of Sex Determination, which is very pleasant to read. For shorter articles, consider Barrett 2002 or just Wikipedia > plant reproductive morphology or Wikipedia > dioecy (the noun form of 'dioecious').

Answer 2

According to "Plant Identification Terminology: An Illustrated Glossary" (Harris & Harris, 2001):

The main difference is the frame of reference. "Monoecious" refers to a whole plant having both male and female parts, while "hermpahroditic" refers to an individual flower having both male and female parts.

Hermaphroditic:

With pistils and stamens in the same flower; bisexual; monoclinous; perfect

• Note: "Perfect" = with both male and female reproductive organs (stamens and pistils).

Monoecious:

Flowers imperfect; the staminate and pistillate flowers borne on the same plant

I will caution you that different sources use "bisexual" inconsistently to refer to either instance.