Scientific Name:
Lactuca sativa
Pronunciation:
lac-TOO-sa sah-TEE-vah
Common Name:
lettuce
Family Name:
Asteraceae
Plant Type:
Annual (true), Weed (horticultural)
Key ID Features:
Common types include: 1. Butterhead lettuce leaves rounded 10-20cm long x 8-15cm wide in loose heads, texture soft, tender, and slightly crinkled or smooth, light green to pale yellow, sometimes with reddish tinges; 2. Romaine lettuce leaves Long, upright leaves with a central rib 20-30cm long x 5-10 cm wide, texture: crisp and firm, especially along the midrib, dark green on the outer leaves, with lighter green to white near the base; 3. Iceberg lettuce leaves tightly packed forming a dense, spherical head, outer leaves 15-20cm long x 10-15cm wide, texture crisp, firm, and smooth, pale green to white at the core; 4. Loose-leaf lettuce leaves loosely arranged with frilly, wavy, or deeply lobed edges, 10-25cm long x 5-15cm wide, texture soft to moderately crisp, depending on the variety, bright green to deep red or bronze hues.
Habit:
Upright
Form:
Oval - vertical
Texture:
Coarse
Mature Height:
0.7 - 1.3m
Mature Spread:
0.3 - 0.6m
Growth Rate:
Fast
Origin:
Central / west Asia, Europe (Siberia to the Mediterranean)
Hardiness Rating:
Zone 2: (-46 to -40 °C)
Exposure:
Full sun
Soil/Growing Medium:
Rocky or gravelly or dry
Landscape Uses:
Urban agriculture
Additional Info:
Google. Note: many varieties exist such as romaine lettuce and iceberg lettuce (with notched, scalloped, frilly or ruffly leaf varieties). Red varieties shown may include L. alkindus.
Leaf Morphology:
Form:
Simple
Arrangement:
Basal
Texture/Venation:
Soft flexible, Pinnate venation
Surfaces:
Glabrous
Colour in Summer:
Green, Dark-red
Colour in Fall:
Yellow
Shapes:
Oblong, Orbicular, Spatulate
Apices:
Rounded
Bases:
Truncate
Margins:
Dentate, Entire, Undulate (wavy)
Inflorescence Type:
Head (capitulum)
Flower Morphology:
Flowers perfect
Corolla Shape:
Ligulate
Ovary Position:
Inferior
Colour (petals):
Not showy, Yellow
Flower Time at Peak:
Aug, Sep
Additional Info:
Leaves not considered edible after flowering
Fruit Type:
Cypsela (achene + calyx)
Fruit Colour:
Brown, Silver
Fruiting Time:
Sep, Oct
Additional Info:
Fruit insignificant
Bark or Stem Colour:
Organ Modifications:
Storage tap root
Propagation:
Seed
Maintenance:
Medium
Pest Susceptibility:
Abiotic disorder, Mildew, Slugs or snails
Specific Pests:
Rabbit, Downy mildew
