Overview
The lecture explains how to distinguish between different types of lettuce, especially wild lettuce and its lookalikes, using physical characteristics and smell.
Identifying Lettuce Types
- The central stem of lettuce can be red or white, not always red.
- Lettuce leaves near the base are always rounded.
- As lettuce grows, its leaves become more serrated or jagged, resembling lion’s teeth.
- Wild lettuce (lactuca virosa) leaves either droop due to their weight or stick out sideways.
- Wild lettuce has an unpleasant odor, especially near the end of its life cycle.
- The stem of wild lettuce is often red and may have thorns.
- Lettuce cariole (likely lactuca serriola) has leaves that grow upwards and rarely have serrated edges.
- The stem of lettuce cariole is red but does not have thorns or prickles.
- Wild lettuce has prickles under the leaf, making it rough to the touch.
- Crushing wild lettuce leaves in your hand releases a less unpleasant smell compared to true wild lettuce.
- All parts of the plant exude a milky sap when broken.
Key Terms & Definitions
- Serrated leaves — Leaves with saw-like or jagged edges.
- Lactuca virosa (Wild lettuce) — A species of lettuce with serrated leaves, red thorny stem, and unpleasant smell.
- Lettuce cariole (Lactuca serriola) — A wild lettuce variety with upward leaves, red but smooth stem, and rarely serrated leaves.
- Prickles — Small, sharp outgrowths found under the leaf.
- Milky sap — White latex-like liquid produced by the plant when broken.
Action Items / Next Steps
- Practice identifying lettuce varieties in the field using these visual and tactile cues.
- Memorize the differences between wild lettuce and lettuce cariole for accurate identification.