Botany for Seed Savers

To be successful seed savers it can be helpful to know some basics of plant botany.

In order to ensure that the collected seed will produce true-to-type offspring we first need to make sure we know what plant we are dealing with and then understand the reproductive mechanism used by the plant.

Botanical Names

Common names can be misleading. They can vary from location to location. They are often determined by how the plant is used in the kitchen rather than what species the plant is. So what is the ‘spinach’ you are growing and therefore what you need to know about it as a seed saver is best determined by finding out it’s botanical name (also known as binomial, scientific or Latin name). 

These names can seem intimidating so it can be useful to remember that you don’t need to be able to pronounce them to use them.

The scientific name is made up of two main parts. The first word identifies the genus and the second word the species (eg. Daucus carota). There may be subspecies which are usually indicated with ‘subsp’. If the species is unknown it may be abbreviated as ‘sp’ (eg. Physalis sp) . To refer to a group of species ‘spp’ is used (eg. Brassica spp).

Finding out the scientific name is usually a straightforward process. Most reputable seed companies put the scientific name on the packet. It is usually in small italic print and may be under the name the seed is being marketed as or it might be tucked away in the small print on the back of the packet. Searching on the internet or on this site are also good ways to track down the scientific name and make sure you are getting the right information for your seed saving efforts for that plant. If you still aren’t able to identify it then, for edible plants, asking on the Connect and Share Forum in the discussion group will likely resolve the mystery. Pictures of the seed and/or the plant will help enormously.

Reproductive Processes

Plants may produce sexually (through pollination and the production of seeds) or asexually (through vegetative propagation).

The two sexual reproductive categories are self-pollinating and cross-pollinating. One of these two processes is used to produce seed.

Self-pollinating

Self-pollinating plants have complete flowers that both produce and accept pollen, and most importantly, either  pollination occurs before they open or they never open. This means that there is little to no chance for external factors such as insects or wind to interfere in the pollination process. 

(diagram of flower parts here?)

Examples of self-pollinating plants are: peas, common beans, lettuce and most tomatoes.

Cross-pollinating

All other sexual reproduction processes are referred to as cross-pollinating. Plants that produce seed by cross pollination may :

  • have complete flowers that both produce and accept pollen, but that are open so that external pollen may be introduced;
  • be dioecious, meaning it has only pollen producing flowers or only pollen accepting flowers, not both;
  • be monoecious, meaning it has both pollen producing flowers and pollen accepting flowers on the same plant, but each individual flower only has one of those functions.

(Diagrams?)

Other factors at play with cross-pollinating plants is whether the pollen is usually carried by insects or the wind.

Cross-pollinating plants may be able to pollinate themselves, however some species are self-incompatible meaning that pollen from another plant is required for pollination to occur. Even though the flower also produces pollen it is not accepted by that plant.

Examples of self-incompatible species are : broccoli and sunflowers.

Vegetative Propagation

In Australia many of our important edible plants are not reproduced through pollination processes producing seed. For many plants this is a natural reproduction mechanism, but it can also be an artificial process that humans have developed, eg. cuttings, grafting, tissue culture etc. Vegetative propagation produces offspring that are genetically identical to the parent plant.

Tuber

Tubers are underground storage organs that develop from the stem or roots of the plant.

Example: potato and sweet potato

Corm

Corms are swollen parts of the plant stem that provides an underground storage organ. The can easily be confused with bulbs but are solid all the way though.

Example: waterchestnut

Bulb

Bulbs are also an underground storage organ formed at the base of the stem. Bulbs are made up of layers, called scales.

Example: shallot and onion

Bulbil or Bulblet

Small bulbs that are formed either in place of a flower head or within or beside bulbs.

Examples: Walking onions, some garlics, perpetual leeks. 

Rhizome

Rhizomes are plant stems that run horizontally under the ground. It puts out both roots and vertical shoots from it’s nodes.

Example: Ginger and turmeric

Stolon

Similar to a rhizome but sprouts from an existing stem and is generally longer than a rhizome.

Examples: strawberry runners

Crop Cycles

Annual

Annual plants are those reproduce and die within one growing season.

Biennial

Biennial plants are those that require a period of vernalisation (winter chilling) in order to initiate the reproductive cycle.

Perennial

Perennial plants are those that live multiple years, growing and reproducing multiple times over their lifetime.

Photo-period

Some plants require a specific day length in order to initiate flowering. Short-day length types require days shorter than a specific number of hours. Long-day length types require days longer than a specific number of hours.

Examples: broadbeans start flowering with the number of daylight hours increases sufficiently to trigger flowering in that variety.


Contributors: Liz Worth


Still to be added to the article above…

Delete the terms from this working list as they are covered above. Some of these may best be explained just by using them in diagrams?

Stamen

Anther

Filament

Pistil

Stigma

Style

Ovary

Petal

Sepal

Cotyledon

Dicotyledon

Monocotyledon

Stem

Xylem

Phleom

Cambium

Hilim

Micropyle

Endosperm

Radicle

Hypocotyl

Endocotyl

Seed coat

Seed leaf = cotyledon

First true leaves

Families

Last updated byLiz