8. Hypericum majus (A. Gray) Rusby (greater St. John’s wort)
H. canadensis L. var. majus A. Gray
Pl. 360 l, m;
Map 1568
Plants perennial
herbs, sometimes with short rhizomes. Stems 10–60 cm long, erect, angled or
narrowly ridged below each leaf, at least toward the tip, green, sometimes
purplish-tinged. Leaves not jointed at the base, ascending or loosely
ascending. Leaf blades 10–45 mm long, 3–10 mm wide, lanceolate to narrowly
elliptic or narrowly oblong, rounded or bluntly to more commonly (in at least
the uppermost leaves) sharply pointed at the tip, narrowed or narrowly rounded
at the base, the uppermost leaves sometimes slightly clasping the stem, the
margins flat, herbaceous to slightly leathery in texture, with mostly 5 or 7
main veins from the base, the surfaces with inconspicuous, minute, yellowish
brown to dark green or black resinous dots, the upper surface green, the
undersurface green, not glaucous. Inflorescences appearing as panicles of 5–30
flowers, rounded to more or less flat-topped in outline. Flowers actinomorphic.
Sepals 5, all more or less similar in size and shape, 4.0–6.5 mm long, usually
becoming slightly enlarged at fruiting, lanceolate, lacking noticeable
yellowish brown or black dots, lines, and/or streaks. Petals 5, 3.5–5.5 mm
long, oblanceolate, bright yellow, occasionally with reddish veins, lacking
noticeable yellowish brown or black dots, lines, and/or streaks, usually shed
by fruiting. Stamens 14–20, the filaments sometimes irregularly spaced but
usually not fused into groups. Ovary 1-locular or appearing partially 3-locular
by intrusion of the parietal placentae into the locule. Styles 3, free above
the base, more or less spreading, the stigmas narrowly capitate. Fruits 5–7 mm
long, at maturity about as long as the sepals, ovoid-conical, widest well below
the midpoint, tapered to the persistent styles, more or less circular in
cross-section, usually maroon at maturity. Seeds numerous, 0.5–0.7 mm long, the
surface with a network of fine to coarse ridges and pits, appearing
longitudinally ribbed, light brown to brown. 2n=16. July–September.
Uncommon, known
thus far only from a single specimen from Sullivan County (northern U.S. south
to Pennsylvania, Oklahoma, and Washington; Canada). Open slopes in ravines.
As noted by
Yatskievych (1990), Steyermark (1963) incorrectly determined the Missouri
plants as H. canadense, a closely related species that occurs only to
the north and east of the state. It is most easily distinguished from H.
majus by its 1- or 3-nerved, linear to narrowly oblanceolate leaves that
are tapered at the base.