Lactuca serriola | Prickly Lettuce | Broom
• Scientific Name: Lactuca serriola
• Common Name(s): Prickly Lettuce, Milk Thistle, Wild Lettuce, Compass Plant, Wild Opium
• Nickname: Broom
• Introduced: L48
• Group: Dicot
• Family: Asteraceae
• Duration: Annual/Biennial
• Growth Habitat: Forb/herb
• Known Human Hazards: See Miscellaneous
• Poisonous Look-Alikes: None
IDENTIFYING CHARACTERISTICS: midrib (central leaf vein) spines and distinct “C” shaped lobe cut-out pattern of the leaves make this plant easy to recognize at any stage of growth / pale yellow dandelion-like flowers / alternating leaves that twist skyward / only branches in pyramid shape atop a long, erect main stem. TIME OF YEAR: blooms July to September / individual plants will remain in bloom for about a month. ENVIRONMENT: roadsides / along embankments / open fields / abandoned fields / fence rows / along railroads / vacant lots / waste areas / disturbed areas. METHOD OF PREPARATION: young leaves mild; good raw or cooked; pick leaves when the plants are less than 8 inches tall and before it flowers / older leaves very bitter; boil in multiple changes of water; can be eaten raw.
FORM: 2 to 7 feet tall / unbranched, except where the upper flowering stems occur / upper portion of plant branches outwards and resembles a pyramid. FLOWERS: dandelion-like / about 1/3 inches across and about 1/2 inch long / pale yellow but can appear to be white from a distance due to the wooly hairs (pappus) on each seed / flower buds are capsule to vase shaped. PETALS: 13 to 27 pale yellow petals (ray flowers; no disk), often tinged purple / flat tips with 5 small teeth. LEAVES: first leaves form a short lived basal rosette / stem leaves alternate / up to 12 inches long and 4 inches across / become smaller as they ascend the stem / waxy blue-green color / often have red around the edges / hairless / pinnately (feather-like) lobed / oblong to lance-shaped or dandelion-like / stiff / shape is distinctive, with the indentation between lobes forming a “C” shape / irregularly toothed around edges / commonly twisted at the base to lie in a vertical north south direction / lobes have a tendency to curve backwards toward the central stem / tips are pointed / short spines along edges and underside of midrib (central leaf vein) / undersides have whitish veins / base of leaf has a pair of angular lobes that clasp stem (no leaf stem) / contain a white milky sap / spines are somewhat soft; incapable of tearing flesh or clothing / emits rank odor when crushed. BRACTS: blue-green / hairless / overlapping in 3 to 5 rows / egg to arrow shaped / leafy / purple tips / rough / differing lengths. STAMEN: 5 / yellow anthers (tips). ROOT: stout / taproot / deep. STEMS: rises from middle of a basal rosette of leaves / erect / stout / woody / light green or straw color; may also be reddish / hairless / may have a few spines toward its base / contain a white milky sap. SEED: achene / grey-brown / oval / smooth / 3 to 6 mm long by 1 to 3 mm wide / slightly flat / striped with 5 to 9 longitudinal ribs / ribs rough near the bottom / short bristly hairs near the top / long white thread-like beak on top; about as long or longer than achene / many a pappus / pappus is silky white, downy, dandelion-like. SIZE: 2 to 7 feet tall.
LEGENDS, MYTHS AND STORIES
• The Ancient Greeks believed its pungent juice to be a remedy against eye ulcers.
• Since early ages, antecedents of the wild lettuce have enjoyed a special status as a beneficial therapeutic plant and were treasured as a tranquilizer and pain killer. The herb valued so much that during the 19th century people used it as a substitute for opium! The story goes that Roman emperor Augustus supposedly constructed a statue of a physician who had recommended lettuce to treat him of a serious ailment. While it is not comprehensible which variety of lettuce cured the emperor, it is believed that the herb was prickly lettuce.
• Known Human Hazards: Eating large quantities of raw young leaves may cause an upset stomach. Also, normal medicinal doses of this plant can cause drowsiness. Excessive doses cause restlessness and overdoses can cause death through cardiac paralysis.
• Similar Species: Lactuca virosa is similar but it’s stem and leaves have a more purple tint, and the leaves are less divided/lobed. Medicinal properties of Lactuca virosa are stronger than L. serriola.
• The sap contains ‘lactucarium’, which has the effects of a mild opium, but without its tendency to cause addiction. Concentrations of lactucarium are low in young plants and most concentrated when the plant comes into flower.
• The leaves can be smoked alone or as part of an herbal blend. The effects of smoking the herb are milder than that of the tea, but take effect sooner. The herb itself is very bitter, and does not taste well when smoked alone.
• This sap hardens and dries when in contact with the air.
• One of the common names given to the plant is ‘compass plant’ because the margins/edges of the leaves are always arranged in a north south direction, to avoid the strong radiation and heat of the noon day sun.
• Finding the flowers on the plant might be difficult. The small pale yellow flowers opens up in the early morning and closes up soon after the sun rises and the temperature gets warm. For example at the end of June, the flowers would be already closing about 9am.
• It’s an ancestor of all forms of cultivated lettuce. Rounded heads of lettuce were not recorded until 1543. There can be a lot of variations in the shape of the leaves of wild lettuces, but they will all have flat leaves, not heads like an iceberg lettuce.
• Another common name for this plant is Wild Opium because the sap contains compounds that are mildly sedating and analgesic.
MEDICINAL PROPERTIES: Hypnotic, Sedative, Anodyne, Antiseptic, Antirheumatic, Antipyretic, Diuretic, Anxiolytic
PARTS USED: Leaves, Stems, Sap
COMMON CONDITIONS: Anxiety – Leaf and stem infusion to calm nerves • Cough (Dry) – Leaf and stem infusion • Fever – Flowers and seeds infusion • Headache – Drink leaf and stem infusion or inhale infusion’s vapor • Insomnia – Leaf and stem infusion to ensure a good nights sleep • Muscle Pain – Leaf and stem infusion • Neuroses – Leaf and stem infusion for symptoms such as insecurity, anxiety, depression and irrational fears • Rheumatism – Drink leaf and stem infusion • Wounds – Apply sap to cuts and scrapes.
• For better memory and to personalize the story a bit; embellish it by incorporating your five senses as much as possible. Mnemonic techniques rely on the fact that your brain uses information from all your senses — touch, sight, smell, hearing, and taste — to form memories. Create images that are clear, pleasant, funny, exaggerated or sensual as long as it can help you remember the information. It will also help your memory retention to act out each part of the mnemonic over and over again.
• Mnemonics, shared in the course, are designed to have the distinguishing plant parts trigger the mnemonic when you spot them in the field. This is called the “trigger effect”. If ever you have trouble recalling the complete mnemonic, after spotting a distinguishing plant feature, study all of the plant parts closely; they will remind you.
VIVIDLY IMAGINE: Grasp the broom with both hands. Now start sweeping around the edges, along the base boards, of your kitchen. What you are sweeping up are a trail of ants that are attracted to something. Keep sweeping around the edge in order to follow the ants’ trail. The ants’ trail diverges suddenly from around the edge of the kitchen and goes straight down the middle of it. The ants’ trail leads right to your kitchen table! Someone has left a half eaten sandwich and a glass of milk, which has spoiled, upon it. You proceed to pour the spoiled milk into the sink and throw the half eaten, ant covered, sandwich into the trash can. Then, of course, you open the door to take the trash out. As soon as you open the door a huge gust of wind starts blowing a variety of leaves inside. You quickly set the trash bag just outside of the door then shut it again. Now you must sweep up the large variety of the leaves. This time, when you open the door to take the trash out, you are shocked to find a full grown lion at your door. It’s gotten into the trash bag you had just left outside and it’s now eating the rest of the half eaten sandwich. You startle the lion when it sees you and it turns white as a ghost. Then the lion stands up on it’s hind two legs and throws it’s front paws into the air like hands; as if you were a police officer, then it backs away slowly. When the lion is gone you are finally able to take the trash out to the curb.
MNEMONIC EXPLAINED: Grasp the broom with both hands (leaves clasp the stem). Now start sweeping around the edges (spikes grow around leaf edges), along the base boards, of your kitchen. What you are sweeping up are a trail of ants that are attracted to something. Keep sweeping around the edge in order to follow the ants’ trail. The ants’ trail diverges suddenly away from the edge of the kitchen and goes straight down the middle of it (spikes also grow along leaf stalk; midrib; underneath). The ants’ trail leads right to your kitchen table! Someone has left a half eaten sandwich (leaves bare “C” shaped edges, like someone had been taking bites out of them) and a glass of milk (the entire plant oozes a milky white sap when cut), which has spoiled, upon it. You proceed to pour the spoiled milk into the sink and throw the half eaten, ant covered, sandwich into the trash can. Then, of course, you open the door to take the trash out. As soon as you open the door a huge gust of wind starts blowing a variety (alternate) of leaves (leaves alternate on the stem) inside. You quickly set the trash bag just outside of the door then shut it again. Now you must sweep up the large variety of the leaves. This time, when you open the door to take the trash out, you are shocked to find a full grown lion (flowers are dandelion-like) at your door. It’s gotten into the trash bag you had just left outside and it’s now eating the rest of the half eaten sandwich. You startle the lion when it sees you and it turns white as a ghost (flowers are pale yellow but can appear to be white from a distance due to the wooly hairs [pappus] on each seed ofter the plant flowers). Then the lion stands up on it’s hind two legs and throws it’s front paws into the air like hands (stem leaves twist to point skyward); as if you were a police officer, then it backs away slowly. When the lion is gone you are finally able to take the trash out to the curb.