# Common Knapweed (*Centaurea nigra subsp. nigra*)

Common Knapweed is a bright purple flower that grows in fields. It's known for its spiky petals and attracts many pollinators.

- **Category:** [Plants](https://www.snappit.app/explore/categories/plant)
- **Rarity:** Common
- **Danger:** 1/5 · Very low
- **Habitat:** Fields and meadows
- **Also known as:** Centaurea nigra

![Common Knapweed](https://res.cloudinary.com/drieglelr/image/upload/v1771426272/objects/4895.jpg)

## Appearance

The Common Knapweed has striking purple-pink, thistle-like flower heads atop erect, branching stems. Its distinctive, bristly, brown-black bracts below the petals give it a scaly appearance, differentiating it from similar wildflowers. Its leaves are lance-shaped and often hairy.

## Taxonomy

- **Kingdom:** Plantae
- **Phylum:** Tracheophyta
- **Class:** Magnoliopsida
- **Order:** Asterales
- **Family:** Asteraceae
- **Genus:** Centaurea

## Interesting facts

- Ancient people sometimes used knapweed to treat skin problems and sore throats!
- Goldfinches love to eat the tiny seeds from its dried flower heads!
- It thrives in poor soil where many other beautiful flowers struggle to survive!
- Its tough stems provide shelter for small insects from the wind.

## Special abilities

- **Deep Drinker:** Common Knapweed has a deep taproot that helps it find water in dry conditions and survive droughts.
- **Sweet Nectar Lure:** Common Knapweed produces abundant, sweet nectar that attracts many insects, helping it get pollinated easily.
- **Seed Spreader:** Common Knapweed can produce numerous seeds annually, ensuring new plants grow even if some are lost.

## Measurements & details

- **Height:** 30-80 cm
- **Spread:** 20-40 cm
- **Flower Size:** 2-4 cm
- **Bloom Season:** Summer to early autumn
- **Edible:** Yes
- **Toxicity:** None
- **Lifecycle:** Perennial
- **Pollination Method:** Insect

## Ecological connections

- **Pollinates:** Honeybee (*Apis mellifera*) — Drinks nectar, carrying pollen between flowers.
- **Pollinates:** Buff-tailed Bumblebee (*Bombus terrestris*) — An important pollinator, attracted to its rich nectar.
- **Parasitizes:** Banded Knapweed Gall Fly (*Urophora quadrifasciata*) — Its larvae create galls within the flower heads.
- **Eats:** [European Goldfinch](https://www.snappit.app/explore/european-goldfinch) (*Carduelis carduelis*) — Feeds on the numerous seeds found within its dried flower heads.

## Traits

- [Aromatic](https://www.snappit.app/explore/traits/aromatic): Aromatic plants produce and emit fragrant volatile organic compounds, often for defense or to attract pollinators.
- [Flowering](https://www.snappit.app/explore/traits/flowering): Flowering plants are any plants that produce flowers as part of their reproductive cycle.
- [Grassland](https://www.snappit.app/explore/traits/grassland): Grassland habitats are terrestrial biomes dominated by grasses and herbaceous plants, supporting a variety of grazing animals.

## Collections

- [Flowers](https://www.snappit.app/explore/collections/flowers)

## Safety

**Danger:** 1/5 · Very low

Explore with care and ask an adult if you’re unsure what to do.

## Frequently Asked Questions

### How to identify Common Knapweed?

Count the petals where you can, then compare the flower's center, its symmetry, how the blooms are grouped and the leaves below. Color varies between garden varieties and shifts with the light. Flower Identifier: upload a photo and compare the visible details.

### How tall is Common Knapweed?

30-80 cm

### How wide does Common Knapweed spread?

20-40 cm

### How big are the flowers on Common Knapweed?

2-4 cm

### When does Common Knapweed bloom?

Summer to early autumn

### Is Common Knapweed edible?

Yes

### Is Common Knapweed toxic?

None

### What is Common Knapweed's lifecycle?

Perennial

## More Plants

- [white snakeroot](https://www.snappit.app/explore/white-snakeroot) (*Ageratina altissima*)
- [tree-of-heaven](https://www.snappit.app/explore/tree-of-heaven) (*Ailanthus altissima*)
- [western sword fern](https://www.snappit.app/explore/western-sword-fern) (*Polystichum munitum*)
- [common milkweed](https://www.snappit.app/explore/common-milkweed) (*Asclepias syriaca*)

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Source: [Common Knapweed: Facts & Places to See — Snappit](https://www.snappit.app/explore/common-knapweed)