Lactuca virosa (leaf)

Nomenclature

Lactuca virosa L.   Asteraceae  
Standardized common name (English): wild lettuce

Botanical Voucher Specimen

Source: MOBOT, Tropicos.org	Source: Royal Botanic Gardens, Kew.	Lactuca virosa var. cruenta Source: Royal Botanic Gardens, Kew.

Organoleptic Characteristics

[Lactuca virosa] is lactescent, and has a strong disagreeable odor like that of opium, and a bitterish, acrid taste. Source: United States Dispensatory (1918)

Macroscopic Characteristics

This is a bright-green plant, from 2 to 7 feet high, covered with a whitish bloom. It has an erect, rigid stem sometimes smooth throughout but at times hairy at the base, with numerous clasping, oblong lance-shaped leaves with finely toothed margins and spiny bristles along the underside of the midrib. The lower leaves are at times 10 inches long and 3 inches wide, but the upper ones are much smaller. The pale yellow flowers, which appear in the early fall, occur in very numerous heads up to a third of an inch broad, having the feathery appearance of the ripe dandelion bloom, arranged in open clusters, each head consisting of 6 to 12 flowers. Source: American Medicinal Plants of Commercial Importance (1930) Lactuca virosa, the acrid or strong-scented lettuce, is biennial, with a stem from two to four feet high, erect, prickly near the base, above smooth and divided into branches. The lower leaves are large, oblongovate, undivided, toothed, commonly prickly on the under side of the midrib, sessile, and horizontal; the upper are smaller, clasping, and often lobed; the bracts are cordate and pointed. The flowers are numerous, of a sulphur-yellow color, and disposed in a panicle. The plant is a native of Europe. Source: United States Dispensatory (1918) Source: PlantaPhile Source: PlantaPhile

Microscopic Characteristics

Large trichome found on the lower epidermis near the vein showing lignified cell observed at 400x with Acidified Chloral Hydrate Glycerol Solution. Source: Elan M. Sudberg, Alkemist Laboratories	Dark brown latex observed at 400x with Acidified Chloral Hydrate Glycerol Solution. Source: Elan M. Sudberg, Alkemist Laboratories

High Performance Thin Layer Chromatographic Identification

Lactuca virosa HPTLC ID - Natural Product Reagent + PEG UV 365 nm Wild Lettuce (leaf) (Lactuca virosa) Lane Assignments Lanes, from left to right (Track, Volume, Sample): 2 μL Rutin, Caffeic Acid, Hyperoside, Chlorogenic Acid ~ 0.1% in Methanol 3 μL Lactuca virosa-1 (leaf) 3 μL Lactuca virosa-2 (herb) 3 μL Lactuca virosa-3 (leaf) 3 μL Lactuca virosa-3 (leaf) 3 μL Lactuca virosa-4 (herb) 3 μL Lactuca virosa-5 (herb) 2 μL Rutin, Caffeic Acid, Hyperoside, Chlorogenic Acid ~ 0.1% in Methanol Reference materials used here have been authenticated by macroscopic, microscopic &/or TLC studies according to the reference source cited below held at Alkemists Laboratories, Costa Mesa, CA.  Stationary Phase Silica gel 60, F254, 10 x 10 cm HPTLC plates  Mobile Phase ethyl acetate: formic acid: glacial acetic acid: water [10/0.9/0.9/2]  Sample Preparation Method 0.3g+3mL CH3OH sonicate/heat @~50° C ~ 1/2 hr  Detection Method Natural Product Reagent + PEG -> UV 365 nm  Reference see Lactuca_virosa_-_Alkemists_Laboratories.jpg Source: Elan M. Sudberg, Alkemist Laboratories