| Family | ROSACEAE |
| Genus species | Petrophytum caespitosum (Nutt.) Rydb. |
| Bibliography | Mem. New. York Bot. Gard. 1: 206 (1900) |
| Native Range | w. & c. USA to ne. Mexico |
| Primary Biome | Temperate |
| Habitat | rocks |
| Altitude | 1100-3000m |
| Description | leaves spathulate to oblanceolate, 7-14mm, uninerved, on both faces grey-green, raceme densely crowded, spicate, 2-5cm long, petals ca. 1mm long |
| Size | 5-10cm |
| Color | white |
| Bloom | summer |
| Ca | ind |
| Type | shrub |
| Cultivation | sunny rock crevices, protection against winter wet alpine house, poor, drained soil, sun |
| Propagation | seed in winter, germ. 1-3 months, 16-18°C cuttings in late summer |
| Synonyms | Eriogynia caespitosa (Nutt.) S.Watson Luetkea caespitosa (Nutt.) Kuntze Petrophytum caespitosum var. elatius (S.Watson) Tidestr. Petrophytum elatius (S.Watson) A.Heller Spiraea caespitosa Nutt. Spiraea caespitosa var. elatior S.Watson |
| Territory | 7 Northern America 73 Northwestern U.S.A. (COL Colorado, IDA Idaho, MNT Montana, WAS Washington) 74 North-Central U.S.A. (SDA South Dakota) 76 Southwestern U.S.A. (ARI Arizona, CAL California, NEV Nevada, UTA Utah) 77 South-Central U.S.A. (NWM New Mexico, TEX Texas) 79 Mexico (MXE Mexico Northeast) |