How to avoid having sex with your (plant) self

How to avoid having sex with your (plant) self

			I>	How many ways can you think of to avoid sex with self if you're a plant?

			II>	Some answers (don't go here until you've thought it through yourself and have as many answers as you can come up with)

			A.	'self incompatibility' (where studied, often 1 locus, many alleles; if alleles match, just say no)

			1.	if pollen and stigma 'recognize' each other (at the molecular level), stigma fails to hydrate pollen (normally, pollen germination is triggered by hydration performed by stigma), Brassica

			2.	Pollen tube's continued growth may be physically blocked by within style Grasses

			3.	Pollen may be induced to 'prematurely ejaculate'--normally the pollen tube 'bursts' when it reaches the ovule; in some incompatibility systems, this is apparently induced prior to reaching ovule

			4.	Abortion of fertilized ovules (cocoa)

			B.	Separate male and female flowers (cucumber, cantaloupe, pumpkin et al.)

			C.	Separate male and female plants (Ginkgo)

			D.	Separate maturation time of male and female parts within a flower

			E.	Separate physical location of male and female parts (dusting/receiving pollen from diff't parts of insect)

			F.	Male and female parts on different points in 'travel paths'; conceptually they collect pollen on ingress; deliver on egress (bug small compared to flower) (some orchids, incl. Coryanthes)