A tall, erect species 3 to 5 ft in cultivation, evergreen or partly deciduous according to the locality and winter; branchlets not angled. Leaves 1 to 2 in. long, 1⁄2 to 11⁄2 in. wide, ovate or triangular-ovate, round or pointed at the tip, truncate at the base, glaucous beneath, distinctly though shortly stalked. Inflorescence a terminal cymose cluster with up to fifteen or sixteen flowers (occasionally more), each flower about 2 in. across, rather cup-shaped owing to the concave shape of the full, broad, overlapping petals. Sepals erect or slightly spreading, ovate-oblong to broad-elliptic, rounded and irregularly toothed at the apex and often with a small apicule near the tip. Petals strongly toothed along the inner margin (i.e., the margin overlapped on the outside by the neighbouring petal). Stamens in five bundles, slightly more than half as long as the petals to almost three-quarters as long. Styles slightly longer than the ovary. Bot. Mag., t. 4949, as H. oblongifolium.
This hypericum was introduced by Thomas Lobb from near Mufflong, Assam, while collecting for Messrs Veitch of Exeter. It was at first identified as H. oblongifolium, though it is quite distinct from the species so named by Choisy (for which see under H. calycinum). It also came to be known as H. hookeranum (q.v.) and was featured under that name in previous editions of this work. Dr Robson, however, has recognised it as a distinct species, which he named and described in 1970 (Journ. R.H.S., Vol. 95 (1970), p. 496).
H. lobbii is moderately hardy, but needs a sheltered place. It flowers from early August to October. It is apt to become gaunt in habit and naked at the base with age, and should be renewed when that condition arrives. It was fairly common in gardens when the first edition of this work was published but seems to have almost dropped out of cultivation since the coming of the Forrest and Wilson introductions from China and, more recently, of such garden varieties as ‘Hidcote’ and ‘Rowallane’. It has, however, survived in the University Botanic Garden, Cambridge, and will shortly be available in commerce once again.