Genus: Lactuca
Family: Asteraceae
Type: Annuals, Perennials, Biennials
Weediness: Most species are weedy
Pollination: Insect

Lactuca, commonly known as lettuce, is a genus of flowering plants in the Sunflower family Asteraceae. The genus includes about 100 species, distributed worldwide, but mainly in temperate Eurasia.


Its best-known representative is the garden lettuce (Lactuca sativa), with its many varieties. But many are just common weeds. They are annuals or perennials. Their height can vary between 10-180 cm. They form heads or capitula in panicles of yellow, brown or purple flowers in ray florets.

The non-edible species may contain bitter elements. Others contain a milky juice.

Growing conditionsEdit


  • Lactuca biennis : Tall Blue Lettuce, Wild Blue Lettuce
  • Lactuca canadensis : Canada Lettuce, Florida Blue Lettuce, Wild Lettuce (North America)
  • Lactuca sativa : Garden Lettuce, Lettuce
  • Lactuca serriola : Prickly Lettuce, China Lettuce, Wild Lettuce (Southern Europe)
  • Lactuca tatarica : Blue Lettuce, Chickory Lettuce, Russian Blue Lettuce (Asia, India)


The garden lettuce is grown as a salad green, other species occur as weeds.

Pests and DiseasesEdit



  • Pea Aphid: Acyrthosiphon pisum
  • Bean Aphid: Aphis fabae
  • Brown Ambrosia Aphid: Dactynotus ambrosiae
  • Potato Aphid: Macrosiphum euphorbiae
  • Green Peach Aphid: Myzus persicae
  • Red Lettuce Aphid: Uroleucon pseudambrosiae
  • Cabbage Aphid: Brevicoryne brassicae
  • Lettuce Aphid: Nasonovia ribisnigri
  • Lettuce Root Aphid: Pemphigus bursarius




  • Pale Legume Bug: Lygus elisus
  • Western Tarnished Plant Bug: Lygus hesperus
  • Tarnished Plant Bug: Lygus lineolaris
  • False Cinch Bug: Nysius raphanus
  • Garden Fleahopper: Halticus bractatus



  • American Serpentine Leafminer: Liriomyza trifolii
  • Chrysanthemum Leafminer: Phytomyza syngenesiae


  • Banded Cucumber Beetle: Diabrotica balteata

Flea Beetles

  • Palestriped Flea Beetle: Systena blanda
  • Redheaded Flea Beetle: Systena frontalis


  • Zebra Caterpillar: Ceramica picta
  • Corn Earworm: Helicoverpa/Heliothis zea
  • Variegated Cutworm: Peridroma saucia
  • Beet Armyworm: Spodoptera exigua
  • Yellowstriped Armyworm: Spodoptera ornithogalli
  • Cabbage Looper: Trichoplusia ni
  • Celery Leaftier: Udea rubigalis
  • Alfalfa Looper: Autographa californica Western US
  • Celery Looper: Anagrapha falcifera
  • Saltmarsh Caterpillar: Estigmene acrea
  • Western Corn Rootworm: Diabrotica virgifera virgifera
  • Western Yellowstriped Armyworm: Spodoptera praefica
  • Angle Shades: Phlogophora meticulosa
  • Autumnal Rustic: Eugnorisma glareosa
  • Cabbage Moth: Mamestra brassicae
  • Common Swift: Korscheltellus lupulina
  • Garden Dart: Euxoa nigricans
  • Ghost Moth: Hepialus humuli
  • The Gothic: Naenia typica
  • Grey Chi: Antitype chi
  • Heart and Club: Agrotis clavis
  • Heart and Dart: Agrotis exclamationis
  • Ingrailed Clay: Diarsia mendica
  • Large Yellow Underwing: Noctua pronuba
  • The Nutmeg: Discestra trifolii
  • Setaceous Hebrew Character: Xestia c-nigrum
  • The Shark: Cucullia umbratica
  • Small Angle Shades: Euplexia lucipara
  • Turnip Moth: Agrotis segetum

Slugs and Snails


Bottom Rot

  • Rhizoctonia

Downy Mildew

Gray Mold

White Mold

  • Sclerotinia

Other ProblemsEdit

Calcium Deficiency


  • Ann Fowler Rhoads and Timothy A. Block (2000). The Plants of Pennsylvania: An Illustrated Manual. Anna Anisko, illustrator. Morris Arboretum, University of Pennsylvania Press. pp. 225-227. 
  • Staff of the L. H. Bailey Hortorium (1976). Hortus Third: A Concise Dictionary of Plants Cultivated in the United States and Canada. Cornell University Press. pp. 631. 
  • Cranshaw, Whitney (2004). Garden Insects of North America: The Ultimate Guide to Backyard Bugs. Princeton University Press. pp. 602. 
  • Pippa Greenwood, Andrew Halstead, A.R. Chase, Daniel Gilrein (2000). American Horticultural Society Pests & Diseases: The Complete Guide to Preventing, Identifying, and Treating Plant Problems (First Edition ed.). Dorling Kindersley (DK) Publishing, inc.. pp. 202. 
Last modified on 21 May 2009, at 22:38