Lactuca sativa

lettuce

 

Lactuca sativa

L. 1753

pronounced: lak-TOO-kuh sat-EYE-vuh

(Asteraceae — the daisy family)

 

common name: lettuce

Lactuca (milk-sap) is the Roman name for lettuce, from lac (lactis), milk; sativa is from sativus, cultivated.

Paintings of what appear to be Cos lettuce have been found in Egyptian tombs dating back to as early as 4500 BC, although there is some uncertainty about their identity. The first authenticated records of cultivated lettuce date back to Greek historical records of 450 BC. By the first century AD, the Romans were growing a number of different lettuce cultivars. Lettuce originates from the wild Lactuca serriola found in the Mediterranean and the Near East, and later introduced into Australia. All of our lettuce cultivars such as Cos, Leaf, Butterhead and Iceberg are regarded as being variants of Lactuca sativa. Lettuce has been transformed from an erect plant with bitter leaves (rather like the plant photographed, that has been allowed to go to seed) to the wonderful varieties found today on our supermarket shelves.

Lettuce is a very easy plant to grow, and also a very easy plant from which to save seed. Flowers produced by the lettuce plant are self-pollinated, so it is difficult to produce seed that has been cross-pollinated. So when seed from your own plants is used to grow the next crop of lettuce, it will be true to type. The only problems that arise will be due to saving seed from a lettuce type that is a hybrid. In this case, there are 4 possibilities:

       • the seed will be sterile and not germinate;
       • the plant will go to flower, but not produce any seed;
       • the plant will produce seed that will germinate, but the resulting plants will throw back to one of the parent plants, or go mad and produce something odd; or
       • you might be lucky and get exactly the same plant.

To save seed, first you should isolate the plants from which you want to collect seed. It is advisable to save seed from more than one plant, because of plant diversity. They are all basically the same plant, but over time they develop slightly different characteristics. Some plants may tolerate more sun, some more shade, others may be more insect tolerant. In a normal season this may not matter, but in any abnormality of weather it is possible to lose the whole crop. Tag the selected plants, and then wait until the plants ‘bolt’. Slowly a stalk will emerge from the top of the plant, and eventually flower. Each flower will self-pollinate and turn into a tiny puff-ball. Let the seed heads dry a little. Carefully cut each stalk and shake it on to a sheet to release the seeds. Let the seed dry for a couple of days – outside if the days are sunny, but cover at night to prevent any mildew or moulds from forming. Alternately, the seed may be put into a paper bag and hung in a dry cupboard. Once it is thoroughly dry, it should be placed in a glass jar and stored in a dark, cool and dry place until the next growing season.

If you are not saving for seed, pull out any plants that ‘bolt’, and compost them. When a plant ‘bolts’, its leaves become very bitter.

Lettice is a food plant for the caterpillars of several Lepidoptera, including:

      • the Cotton Cutworm Spodoptera litura;
      • the Lucerne Leaf Roller Merophyas divulsana; and
      • the Beet Armyworm Spodoptera exigua.

 

Photographs taken in Picnic Bay 2010
Page last updated 25th January 2019