# Kalm's St. John's-wort (*Hypericum kalmianum*)

Kalm's St. John's-wort is a bright yellow flower that blooms in summer. It has pretty petals and is loved by butterflies and bees!

- **Category:** [Plants](https://www.snappit.app/explore/categories/plant)
- **Rarity:** Common
- **Danger:** 1/5 · Very low
- **Habitat:** Grasslands

![Kalm's St. John's-wort](https://commons.wikimedia.org/w/index.php?title=Special:Redirect/file/Hypericum_kalmianum_-_Botanischer_Garten%252C_Frankfurt_am_Main_-_DSC02524.JPG&width=800)

Photo: Daderot, CC0 · [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Hypericum_kalmianum_-_Botanischer_Garten%252C_Frankfurt_am_Main_-_DSC02524.JPG)

## Appearance

The Kalm's St. John's-wort is a small, bushy shrub featuring abundant, cheerful yellow flowers with five petals and a burst of long, prominent stamens. Its narrow, lance-shaped leaves are bright green and often have tiny translucent dots, making it distinct from other shrubs.

## Taxonomy

- **Kingdom:** Plantae
- **Phylum:** Tracheophyta
- **Class:** Magnoliopsida
- **Order:** Malpighiales
- **Family:** Hypericaceae
- **Genus:** Hypericum

## Interesting facts

- After blooming, it forms cool, woody seed capsules that look like tiny bells!
- Its cheerful yellow flowers can actually close up at night or on cloudy days!
- Its leaves have tiny, see-through dots you can spot when held to light!
- Named after Pehr Kalm, a Swedish explorer who studied North American plants!

## Special abilities

- **Pollinator Beacon:** Kalm's St. John's-wort has bright yellow flowers with numerous stamens that act like a glowing target, guiding busy bees to nectar.
- **Water-Wise Roots:** Its adaptable root system helps it survive by finding moisture in diverse soils, tolerating both some drought and dampness.
- **Winter Armor:** This woody perennial can shed its leaves but regrows vigorously in spring, allowing it to withstand cold winters.

## Measurements & details

- **Height:** 30-90 cm
- **Spread:** 30-90 cm
- **Flower Size:** 2-3 cm
- **Bloom Season:** Late Spring to Late Summer
- **Edible:** No
- **Toxicity:** Mild
- **Lifecycle:** Perennial
- **Pollination Method:** Insect

## Ecological connections

- **Pollinates:** Honey Bee (*Apis mellifera*) — Gathers nectar and pollen from its sunny blooms.
- **Pollinates:** [Common Eastern Bumble Bee](https://www.snappit.app/explore/common-eastern-bumble-bee) (*Bombus impatiens*) — Visits flowers for nectar, helping pollen move.
- **Pollinates:** Drone Fly (*Eristalis tenax*) — Looks like a bee while visiting flowers for sweet nectar.

## Traits

- [Flowering](https://www.snappit.app/explore/traits/flowering): Flowering plants are any plants that produce flowers as part of their reproductive cycle.
- [Summer Blooming](https://www.snappit.app/explore/traits/summer-blooming): Summer blooming plants produce their flowers during the summer season, often providing vibrant color when many other plants have finished.
- [Fragrant Flower](https://www.snappit.app/explore/traits/fragrant-flower): Fragrant flowers emit a pleasant aroma, often to attract pollinators or for defense.
- [Medicinal](https://www.snappit.app/explore/traits/medicinal): Medicinal plants possess chemical compounds that can be used for therapeutic purposes to treat illnesses or maintain health.
- [Edible](https://www.snappit.app/explore/traits/edible): Edible plants are those parts of a plant that are considered safe for human consumption.
- [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.
- [Pollinator Magnet](https://www.snappit.app/explore/traits/pollinator-magnet): Describes plants that are particularly attractive and beneficial to a wide range of pollinating organisms.

## Collections

- [Plants](https://www.snappit.app/explore/collections/plants)

## Safety

**Danger:** 1/5 · Very low

Always look but don't touch plants unless you know they are safe.

## Frequently Asked Questions

### How to identify Kalm's St. John's-wort?

Start with the whole plant, then compare leaf arrangement, leaf edges, stems and any flowers or fruit. Opposite leaves grow in pairs; alternate leaves come one at a time along the stem. These details tell you far more together than a single green leaf does. Plant Identifier: upload a photo and compare the visible details.

### How tall is Kalm's St. John's-wort?

30-90 cm

### How wide does Kalm's St. John's-wort spread?

30-90 cm

### How big are the flowers on Kalm's St. John's-wort?

2-3 cm

### When does Kalm's St. John's-wort bloom?

Late Spring to Late Summer

### Is Kalm's St. John's-wort edible?

No

### Is Kalm's St. John's-wort toxic?

Mild

### What is Kalm's St. John's-wort'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: [Kalm's St. John's-wort: Facts & Places to See — Snappit](https://www.snappit.app/explore/kalms-st-johns-wort)