jimsonweed (Datura stramonium)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

COMMON NAMES:
purple thorn-apple
moonflower
thornapple
jimsonweed
stinkwort
mad apple
common thorn-apple
jimson weed
thorn apple
purple stramonium
stramonium
Jamestown weed

 

The common name 'jimsonweed' is probably a corruption of 'James-

town Weed,' referring to where this species was first observed in

North America.

 

SCIENTIFIC SYNONYMS:
Datura stramonium L. var. tatula (L.) Torr.
Datura tatula L.

 

CONFIRMATION STATUS: Pending confirmation.

 

TAXONOMY: The currently accepted scientific name of jimsonweed
is Datura stramonium L. Two varieties of jimsonweed have been des-
cribed. The typical variety has green stems and white flowers, while var.
tatula has purple stems and pale violet flowers. However, variety tatula
is now generally not accepted; charcteristics subscribed to it are now

seen as morphological variations within the single species.

 

NATIVE STATUS: Introduced, United States and Canada.

 

GENERAL BOTANICAL CHARACTERISTICS:

 

Habit: This adventive plant is a summer annual about 3-5' tall that branch-

es dichotomously. The stems are green or purple and largely hairless, al-

though young stems often have conspicuous hairs.

 

Leaves: The alternate leaves are up to 8" long and 6" across (excluding

the petioles). They are ovate or ovate-cordate in outline, but pinnately

lobed. These lobes are somewhat shallow and pointed at their tips; there

are usually 2-3 of these lobes on each side of the leaf blade. The margin

of each leaf may have a few secondary lobes or coarse dentate teeth,
otherwise it is smooth or slightly undulate. The leaves may be slightly

pubescent when young, but become hairless with age; the upper surface

of each leaf is often dark green and dull. The foliage of Jimsonweed

exudes a bitter rank odor.

 

Flowers: Individual flowers occur where the stems branch dichotom-

ously; the upper stems also terminate in individual flowers. The fun-

nel-form corolla of each flower is up to 5" long and 2" across when

fully open; its outer rim has 5 shallow lobes. Each of these lobes forms

an acute point in the middle.The corolla is white or pale violet through-

out, except at the throat of the flower, where thick veins of dark violet

occur. The light green calyx is shorter than the corolla and conspicuous-

ly divided along its length by 5 membranous wings. The flowers don't

open up fully until around mid- night and close early in the morning;

each flower lasts only a single day.

 

Fruit/Seeds: Each flower is replaced by a hard fruit that is dry and spiny;

it is about 1½" long, 1" across, and spheroid-ovoid in shape. Underneath

each fruit is a truncated remnant of the calyx that curves sharply down-

ward. These fruits are initially green, but become brown with maturity;

they divide into 4 segments to release the seeds. The large seeds are dull,

irregular, and dark-colored; their surface may be pitted or slightly reticu-

lated.

 

Roots: The root system consists of taproot that is shallow for the size of

the plant; it branches frequently. Jimsonweed spreads by reseeding itself.

 

REGENERATION PROCESS: Jimsonweed propogates itself by reseed-

ing.

 

HABITAT TYPES: Jimsonweed is probably adventive from tropical

America and was first observed in the United States at the James-
town colony during the 17th century. Typical habitats include cropland
(particularly corn fields), fallow fields, old feed lots, piles of soil at con-

struction sites, mounds of decomposed mulch and discarded vegetation,

and miscellaneous waste areas. Disturbed areas are strongly preferred.

 

SITE CHARACTERTICSTICS: Jimsonweed prefers full or partial

sun, moist to mesic conditions, and a rich fertile soil with high nitrogen

content. This type of soil is necessary to supply the nutrients that are

required by the prodigious growth of this annual plant. The foliage is

often pitted by tiny holes that are made by flea beetles (the same species

that attack eggplant). The seeds can remain viable in the ground for

several years.

 

SEASONAL DEVELOPMENT: The blooming period occurs from mid-

summer to early fall and lasts about 2 months.

 

GENERAL DISRIBUTION: Jimsonweed is found throughout most

of North American with the exceptions of Wyoming in the United
States, and Newfoundland and the northern territories of Canada.

 

SKY MEADOWS DISTRIBUTION: To be determined.

 

IMPORTANCE AND USES: The flowers are pollinated by Sphinx
moths. Various species of beetles are attracted by the flowers, especial-

ly at night, where they steal nectar and chomp on the pollen. The foliage

and its juices are consumed by flea beetles, aphids, psyllids, and other

small insects; their presence attracts ladybird beetles and other predatory
insects. The foliage and seeds contain an impressive assortment of toxic
alkaloids that can be fatal to mammalian herbivores and humans. Some

of these alkaloids are mildly narcotic and hallucinogenic. The immature

seeds are especially poisonous; as few as 20 seeds can fatally poison a

child. It is doubtful that birds make any use of these toxic seeds. Humans

help to spread the seeds around through activities that are related to agri-

culture, construction, and landscaping.

 

 

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