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(Petrophytum caespitosum)
Mat Rock Spirea (Petrophytum caespitosum)
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Matt Berger
CC BY 4.0
Image By:
Matt Berger
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Copyright:
CC BY 4.0
Copyright Notice:
Photo by: Matt Berger | License Type: CC BY 4.0 | License URL: http://creativecommons.org/licenses/by/4.0/ | Rights Holder: Matt Berger | Publisher: iNaturalist | Date Created: 2019-09-28T12:57:59-07:00 |
Estimated Native Range
Summary
Petrophytum caespitosum, commonly known as Mat Rock Spirea, is a perennial herb native to alpine and subalpine regions, often found growing in rocky crevices and talus slopes in the western United States and Mexico. It forms very low, dense mats that can spread up to 80 centimeters wide, with a unique ability to cling to vertical surfaces by its roots. This adaptation allows it to survive in its harsh native habitat, where it plays a role in soil stabilization and provides nectar for pollinators. The plant is characterized by its spikelike clusters of flowers, which are borne on erect peduncles up to 10 centimeters tall. Each inflorescence is densely packed with small white flowers, each with five petals, blooming in spring, summer, and fall. The flowers are modest in size but can be quite showy en masse due to their abundance.
Mat Rock Spirea is valued for its ability to thrive in rock gardens, alpine gardens, and other challenging garden environments where it can provide ground cover and erosion control. It is also appreciated for its low water requirements and its ability to grow in well-drained soils. In cultivation, it prefers full sun and tolerates a range of soil types, provided they have good drainage. While it is generally low-maintenance, it can be susceptible to root rot if overwatered or planted in poorly drained soils.CC BY-SA 4.0
Mat Rock Spirea is valued for its ability to thrive in rock gardens, alpine gardens, and other challenging garden environments where it can provide ground cover and erosion control. It is also appreciated for its low water requirements and its ability to grow in well-drained soils. In cultivation, it prefers full sun and tolerates a range of soil types, provided they have good drainage. While it is generally low-maintenance, it can be susceptible to root rot if overwatered or planted in poorly drained soils.CC BY-SA 4.0
Plant Description
- Plant Type: Subshrub
- Height: 0.1-0.5 feet
- Width: 1-3 feet
- Growth Rate: Slow
- Flower Color: White
- Flowering Season: Spring, Summer, Fall
- Leaf Retention: Evergreen
Growth Requirements
- Sun: Full Sun
- Water: Low, Medium
- Drainage: Medium, Fast
Common Uses
Erosion Control, Low Maintenance, Rock Garden
Natural Habitat
native to alpine and subalpine regions, often found growing in rocky crevices and talus slopes in the western United States and Mexico
Other Names
Common Names: Rock-Spiraea, Tufted Rockmat, Mattspirea
Scientific Names: , Petrophytum caespitosum, Petrophyton caespitosum, Petrophytum caespitosum subsp. caespitosum, Spiraea caespitosa, Petrophyton caespitosum var. caespitosum, Petrophytum caespitosum var. caespitosum, Spiraea caespitosa var. elatior, Eriogynia caespitosa, Spiraea coespitosa
GBIF Accepted Name: Petrophytum caespitosum (Nutt.) Rydb.