Article from Bean's Trees and Shrubs Hardy in the British Isles
Recommended citation
'Hypericum × moseranum' from the website Trees and Shrubs Online (treesandshrubsonline.
A hybrid between H. patulum and H. calycinum, raised in Moser’s nursery at Versailles about 1887. It is a dwarf plant of tufted habit, sending up arching, reddish shoots each year 1 to 11⁄2 ft long. Leaves intermediate between those of the parents and up to 2 in. long, ovate, rather glaucous beneath. Flowers from one to five in a cluster at the end of the shoot, but not more than one of each cluster is open at any one time; each flower 2 to 21⁄2 in. across, with broad, overlapping, golden yellow petals. Stamens in five bundles with pinkish-purple anthers.
This is one of the most attractive of the hypericums, whose only fault is that it is frequently killed back in winter, and when planted in a group, leaves the ground bare until the young growths push again, which is not until May. It is hardier than H. patulum, although it has inherited the cymose inflorescence of that species, and thus a great flower beauty. A bed at Kew stood unchanged for twenty years, only protected by dry leaves during hard frost. It flowers from July up to October.