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scarlet pimpernel (Anagallis arvensis)




















scarlet pimpernel
red pimpernel
red chickweed
poorman's barometer
poor man's weather-glass
shepherd's weather glass
shepherd's clock


Some of the above listed common names may apply to one or both

of the subspecies associated with scarlet pimpernel.


SCIENTIFIC SYNONYMS: There are no scientific synonyms for
Anagallis arvensis L.


CONFIRMATION STATUS: Pending confirmation.


TAXONOMY: The currently accepted scientific name for scarlet
pimpernel is Anagallis arvensis L. Until recently, it has been assumed
there were two subspecies of Analallis arvensis found in North Amer-

ica: 1) subspecies arvensis, and 2) foemina (Mill.) Schinz & Thell.

Subspecies foemina is commonly called poorman's weatherglass; it

has not been recorded as occurring in Virginia. However, in 2007, a

molecular phylogenetic study showed that Anagallis foemina is more

closely related to Anagallis monelli than to Anagallis arvensis, and

should be treated as a separate species. Scarlet pimperenel is often

mistakenly identified as common chickweed (Stellaria media), how-

ever scarlet pimpernel has square stems and reddish-orange flowers

while common chickweed has round stems and white flowers. Add-

itionally, the purple spots on the lower leaf surfaces of scarlet pim-

pernel help to distinguish this weed from other similar weed species.


NATIVE STATUS: Introduced, United States and Canada.




Habit: Scarlet pimpernel is a low-growing, branching, winter or sum-

mer annual, and occasionally, biennial broadleaf plant. The mature

plant grows up to 1-1/3 feet tall. Stems are square in cross-section,

fleshy, hairless, branching at the base, and grow upright or prostrate.


Leaves: Leaves are stalkless, oval to football shaped with triangular

tips, reaching 1 inch in length, and sometimes dotted with dark or

purplish glands on the lower surface. Leaves are opposite to one
another along the stem, or sometimes around the stem in a whorl

(occassionally occurring in whorls of three) and are without petioles.

Leaves may have tiny hairs.


Flowers: Solitary flowers arise from the area between the stem and

leaves (leaf axils) and occur on relatively long stalks (pedicels).

Flowers have five salmon-orange colored petals, slender stalks; on

rare occasion flowers can be brick red, bright blue or white. The

flowers are only open during dry, sunny weather; they remain closed

during cool or cloudy weather. Even in bright weather, the flowers

are only open for a comparatively short time - never opening until

between eight and nine in the morning and shutting up before three

o'clock in the afternoon. As the petals are only brilliantly coloured

on their upper faces, the flowers when closed disappear from view

among the greenness of the leaves.


Fruit/Seeds: Fruit are tiny, round capsules about 1/10 to 1/6 of an

inch (3–4 mm) in diameter that contain many small (1.3 mm long),

brown seeds. They are suspended from downward curved stalks. A

lid at the top of each capsule opens and releases seeds. Seeds are egg

to football shaped, threesided, black or brown, 1/25 to 1/16 of an inch

(1–1.5 mm) long, and covered with small wartlike projections.


Roots: The roots are fibrous.


REGENERATION PROCESS: Scarlet pimpernel propogates itself

by reseeding.


HABITAT TYPES: Scarlet pimpernel occurs in a wide range of

habitats, many of which are human created. Typical habitats include

crop fields, vineyards, orchards, pastures, grassland, turf, gardens,

landscaped areas, urban sites, roadsides, margins of vernal pools,

streams, marshes, coastal terraces, ocean beaches, and other disturb-

ed sites.


SITE CHARACTERISTICS: Scarlet pimpernel has a wide range

of soil situations suitable for growth. It can thrive in light (sandy),

medium (loamy) and heavy (clay) soils. It also can thrive in acid,

neutral and basic (alkaline) soils. It prefers full sun to partial sum; it

cannot grow in the shade. It requires dry or moist soil.


SEASONAL DEVELOPMENT: Scarlet pimpernel has a long

blooming period - flowering generally takes place from March into

August (June into August most common), with some plants bloom-

ing into September.


GENERAL DISTRIBUTION: Scarlet pimpernel occurs in all

states in the United States except Colorado, Wyoming, and North

Dakota, and in all Canadian provinces except Manitoba, the Labra-

dor region of Newfoundland and the far northern provinces. It has

not been reported as occurring in Alaska.




IMPORTANCE AND USES: There is insufficient information per-

taining to the value scarlet pimpernel may have for wildlife. Butter-

flies, and possibly some ants, may be attracted to this non-native plant.


If consumed, scarlet pimpernel can be toxic to livestock and humans.
Toxicity level ranges from virtually nontoxic to fatally toxic and ap-

pears to correlate with summer rainfall levels. Although leaves contain

saponins and other potentially toxic compounds, it is uncertain as to

what substance is responsible for livestock poisonings. If more palat-

able forage is available, livestock will avoid eating this bitter-leaved




Back to Inventory of Herb/Forb Families and Species

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