Petrophyton caespitosum
Encyclopedia
Petrophyton caespitosum (orth. var. Petrophytum caespitosum) is a species of flowering plant in the rose family
known by the common name mat rock spiraea. It is native to the western United States where it grows in mountainous areas from the Sierra Nevada to the Rocky Mountains
. It grows among rocks in forested and woodland habitat. This is a very low matted shrub
growing in carpets up to 80 centimeters wide, creeping over rocks. The plant often grows on vertical surfaces and hangs by its roots, which cling to cracks in rock. The stems are thick and very short, covered densely in rosettes of oval leaves. It produces many inflorescence
s which are spikelike clusters of flowers arising on erect peduncles
up to 10 centimeters tall. Each inflorescence is packed with flowers, each with five tiny white petals, many whiskery stamen
s, and usually 5 hairy pistils
. The flower parts dry and may fall away, leaving a cluster of developing fruits, follicle
s containing the seeds.
Rosaceae
Rosaceae are a medium-sized family of flowering plants, including about 2830 species in 95 genera. The name is derived from the type genus Rosa. Among the largest genera are Alchemilla , Sorbus , Crataegus , Cotoneaster , and Rubus...
known by the common name mat rock spiraea. It is native to the western United States where it grows in mountainous areas from the Sierra Nevada to the Rocky Mountains
Rocky Mountains
The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...
. It grows among rocks in forested and woodland habitat. This is a very low matted shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
growing in carpets up to 80 centimeters wide, creeping over rocks. The plant often grows on vertical surfaces and hangs by its roots, which cling to cracks in rock. The stems are thick and very short, covered densely in rosettes of oval leaves. It produces many inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
s which are spikelike clusters of flowers arising on erect peduncles
Peduncle (botany)
In botany, a peduncle is a stem supporting an inflorescence, or after fecundation, an infructescence.The peduncle is a stem, usually green and without leaves, though sometimes colored or supporting small leaves...
up to 10 centimeters tall. Each inflorescence is packed with flowers, each with five tiny white petals, many whiskery stamen
Stamen
The stamen is the pollen producing reproductive organ of a flower...
s, and usually 5 hairy pistils
Gynoecium
Gynoecium is most commonly used as a collective term for all carpels in a flower. A carpel is the ovule and seed producing reproductive organ in flowering plants. Carpels are derived from ovule-bearing leaves which evolved to form a closed structure containing the ovules...
. The flower parts dry and may fall away, leaving a cluster of developing fruits, follicle
Follicle (fruit)
In botany, a follicle is a dry unilocular many-seeded fruit formed from one carpel and dehiscing by the ventral suture in order to release seeds, such as in larkspur, magnolia, banksia, peony and milkweed....
s containing the seeds.