A-Z of botany: Dichogamy

The term may sound unfamiliar but it is something that lots of plants exhibit and is it a way that plants use to prevent self pollination and a small gene pool, as unwanted in the plant world as it is in humans and other breeding systems. (except for those apomictic plants mentioned the other day, of course)

dichogamous-copy

Most flowers have both male and female parts so it would be easy for the pollen of a flower to land on its stigma and effectively pollinate itself. Plants have various ways to prevent this and the two parts may be far apart or, as in dichogamous plants, the two parts ‘ripen’ at different times. So some plants open their stigmas first, before the stamens shed pollen and others shed pollen first and when it is gone the stigmas then become receptive. A plant that is functionally male first is called protandrous and one that is female first is protogynous (sensible really since proto means first). If the style, on which the stigma is located, is longer than the stamens it can help prevent stray pollen landing on it.

dichog

Foxgloves are protandrous and the stamens start to open as soon as the flower expands. Afterwards they are then functionally female. This means that the lower flowers on a spike are female and the upper ones are male. Since bumble bees always fly to the base of the spike and work their way up it ensures that pollen from one flower is deposited on the flowers of a different plant.

digitalis-pams-choice-flowers3-copy-2

 

, , ,

2 Comments on “A-Z of botany: Dichogamy”

  1. derrickjknight
    October 15, 2016 at 9:19 am #

    More fascinating education

  2. susurrus
    October 15, 2016 at 8:54 pm #

    I hadn’t realised that there’s a method to the ways bees graze on foxgloves. I’ll be watching out for this next year.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Ravenscourt Gardens

Learning life's lessons in the garden!

One Good Life in Los Angeles

Roslyn's observations about places and events around Southern California

IGPS Blog

The Irish Garden Plant Society - Lovers of Irish plants and gardens

AltroVerde

un altro blog sul giardinaggio...

vegetablurb

four decades of organic vegetable gardening and barely a clue

The Long Garden Path

A walk round the Estate!

Flowery Prose

Sheryl Normandeau's growing words....

ontheedgegardening

Gardening on the edge of a cliff

Uprooted Magnolia

I am a freelance Photographer born and raised in the Southeast. I have uprooted my life in Macon Georgia for a new life as an unlikely cowgirl in love with a handsome cowboy in Wyoming. I hope you enjoy my photo journal on life, love, and the spirit of Wyoming.

Interesting Literature

A Library of Literary Interestingness

Garden Variety

A Gardening, Outdoor Lifestyle and Organic Food & Drink Blog

For the Love of Iris

Articles, Tips and Notes from Schreiner's Iris Gardens

One Bean Row

Words and pictures from an Irish garden by Jane Powers

Plant Heritage

The world's leading garden plant conservation charity

HERITAGE IRISES

An English experience of gardening in Ireland - and back in the UK

%d bloggers like this: