There are over 400 Hypericum species and all have yellow flowers, usually with 5 petals. They can be annuals, perennials and even shrubs. Hypericum athoum is one of the jewels of the genus making a very nice clump that flowers much of the middle and late summer.
H. athoum makes a nice tight clump. Leaves are 8-15 mm long, ovate to oblong-ovate and softly hirsute (ie hairy). It forms clusters of 2 to 7 yellow flowers, about 15 mm in diameter. The flowers are quite large for the size of the plant.
The common name, St. John’s wort is used to name many of the Hypericum species and is of little use in identifying plants. There is little information about the hardiness of this species, and it may not be long lived, as is the case with many smaller hypericum species.
A great rock garden plant that deserves to be grown more frequently.
Hypericum athoum
(hy-PER-ee-kum ath-oo-um)
Life Cycle: perennial
Height: 1 cm (4 inch)
Bloom Time: mid to late summer
Natural Range: Greece
Habitat: shady rocks, gravelly soil
Synonyms: none
Cultivation of Hypericum athoum:
Light: full sun to part shade
Soil: humus rich gravelly soil
Water: drought tolerant once established
USDA Hardiness Zone: range not known – overwinters in zone 5
Propagation: seed and cuttings in late summer