perennial ragweed

Names and Synonyms

Common Names

• Cuman ragweed
• perennial ragweed
• western ragweed
• Dunbible-weed
• Roman wormwood

Scientific Names

Accepted name

Synonyms

• Ambrosia californica
• Ambrosia lindheimeriana
• Ambrosia psilostachya var. coronopifolia
• Ambrosia coronopifolia
• Ambrosia psilostachya var. californica
• Ambrosia psilostachya var. lindheimeriana
• Ambrosia rugelii

Regional and Traditional Names

Sources: Wikidata, Catalogue of Life

Taxonomical Classification

This plant, Ambrosia psilostachya, belongs to the kingdom Plantae and the phylum Streptophyta. It is classified under the class Equisetopsida and the subclass Magnoliidae within the order Asterales. Finally, it is a member of the family Asteraceae and the genus Ambrosia.

Sources: The World Checklist of Vascular Plants (WCVP)

Distribution

This plant exhibits a broad distribution across several regions within the European continent. In Northern Europe, its presence is documented in Denmark, Great Britain, Norway, and Sweden. Moving toward the center of the continent, it can also be found in Middle Europe. Specifically, the species is recorded as growing in Austria. Together, these locations highlight the plant's ability to inhabit various northern and central territories.

Sources: The World Checklist of Vascular Plants (WCVP)

Botanical Identification

Ecology

The ecology of Ambrosia psilostachya is characterized by its ability to thrive in disturbed environments, specifically favoring anthropogenic landscapes such as managed areas and roadsides. This species is typically found at very low altitudes, with an elevational range that reaches a maximum of only 15 m AMSL, indicating a preference for coastal or lowland plains. Its presence in managed habitats suggests a high tolerance for human-induced soil disturbance and shifting ecological succession patterns.

Elevational range max:

15 m AMSL

Habitat :

roadsides, managed

Life history

The life history of Ambrosia psilostachya is characterized by a perennial lifecycle, allowing the plant to persist across multiple growing seasons. As a member of the cryptophyte group, its regenerative organs are protected below the soil surface, a strategy that facilitates survival through unfavorable environmental conditions. Specifically, its life form is classified as a geophyte, meaning it relies on underground storage organs to endure periods of dormancy and to re-emerge during favorable climatic cycles.

Life form :

geophyte

Life form :

cryptophyte

Lifecycle :

perennial

Morphology

The morphology of Ambrosia psilostachya is characterized by its growth form as a non-woody herb and forb. It is a terrestrial, self-supporting plant that does not function as a climber or an epiphyte, nor does it act as a parasite, growing instead as an independent organism. In terms of stature, the plant exhibits significant variability in height, with specimens ranging from a minimum of 0.2 m to a maximum of 2 m, maintaining an average plant height of approximately 0.45 m.

Aquatic :

terrestrial

Climber :

self-supporting

Epiphyte :

terrestrial

Growth form :

herb

Growth form :

forb

Parasite :

independent

Plant height max:

2 m

Plant height mean:

0.45 m

Plant height min:

0.2 m

Woodiness :

non-woody

Physiology

The physiology of Ambrosia psilostachya is characterized by a C3 photosynthetic pathway, indicating its reliance on the standard Calvin cycle for carbon fixation. As a non-carnivorous species, it obtains its nutrients through soil uptake rather than through the capture of prey. Its leaf morphology plays a critical role in its resource management, exhibiting a mean Specific Leaf Area (SLA) of 193.4 cm²/g, which reflects its strategy for balancing light interception and water loss. The leaf dimensions vary significantly, with lengths ranging from a minimum of 5 cm to a maximum of 12 cm, while the widths fluctuate between a minimum of 2 cm and a maximum of 4 cm. Consequently, the plant maintains a mean leaf size of approximately 5.8775 cm², a structural configuration optimized for its specific ecological niche.

Carnivory :

non-carnivorous

Leaf length max:

12 cm

Leaf length min:

5 cm

Leaf size mean:

5.8775 cm²

Leaf width max:

4 cm

Leaf width min:

2 cm

Photosynthetic pathway :

C3

Specific Leaf Area (SLA) mean:

193.4 cm²/g

Reproduction

The reproduction of Ambrosia psilostachya is characterized by a sexual process, as asexual reproduction is notably absent. The flowering period typically commences in August and extends through October. During this phase, the plant relies on insect pollination, utilizing various insect vectors to facilitate fertilization; notably, self-fertilization is absent, ensuring genetic diversity through cross-pollination. The resulting fruit is classified as an achene, which is indehiscent, meaning it does not burst open at maturity to release its contents. The seeds produced are quite small, with a mean mass of approximately 0.0066035 g, ranging from a minimum of 0.00648 g to a maximum of 0.006727 g. Dispersal of these seeds occurs via an anthropochorous syndrome, indicating that human activity plays a role in the movement and spread of the species.

Dehiscence :

indehiscent

Dispersal syndrome :

anthropochorous

Flowering time :

Aug

Flowering time :

Oct

Fruit type :

achene

Pollination syndrome :

insect

Reproduction asexual :

absent

Seed mass max:

0.006727 g

Seed mass mean:

0.0066035 g

Seed mass min:

0.00648 g

Self fertilization :

absent

Sources: Global Inventory of Floras and Traits (GIFT)

Chemicals

Ambrosia psilostachya has 1 reported phytochemicals identified across 0 scientific publications and several other databases. The most consistently reported chemicals include cumanin.

cumanin

1. Journal of ethnopharmacology

Activities

Ambrosia psilostachya has 1 reported activities identified across 0 scientific publications and several other databases. The most consistently reported activities include Cytotoxic.

Cytotoxic

1. Journal of ethnopharmacology