Hypericum ascyron subsp. pyramidatum (Nomenclature)
Plant 0.5-2 m tall. Leaves 40-80 ´ 18-33 mm, ovate-lanceolate to lanceolate or oblong, base cordate to rounded. Flowers 40-70 mm in diam. Sepals 8-13 mm wide, ovate to lanceolate or oblong-elliptic, acute to shortly acuminate. Stamens yellow. Styles 3-7 mm, 0.8-1.5 ´ ovary, almost free or rarely up to 0.8 united. Capsule ovoid.
Canada (Quebec, Ontario, Manitoba?), USA (north-east, from Minnesota to Massachusetts and S. to Missouri, Ohio and Maryland).
The characteristic features of the American population, viz. acute to acuminate sepals and shortly connate styles, are certainly not constant enough to allow it to be recognised as a species. However, these characters rarely occur together in Asia, where almost free styles are not uncommon but acute sepals appear to be confined to Japan and acuminate sepals are apparently absent. It would seem appropriate, therefore, to give the American population subspecific rank.
W. G. Dore suggested that the sporadic distribution of H. ascyron in Canada, which seems to coincide well with earlier Indian camp sites, indicates that this plant was probably distributed by aborigines (Gillett & Robson, 1981: 25), though the reason for this association is not clear.