Hypericum punctatum
Hypericum tenuifolium
spotted St. John's-wort
Atlantic St. John's-wort
clustered, internodes not lined, with black glands scattered all over.
internodes 6-lined at first, becoming 4-lined, then terete.
spreading or ascending, usually sessile, rarely petiolate (to 1 mm);
blade elliptic or oblong to lanceolate or triangular-lanceolate, or oblanceolate, 14–40(–58) × 3–17(–22.5) mm, base cordate to narrowly cuneate, margins plane, apex usually rounded to retuse, rarely acute to obtuse, midrib with 3–5 pairs of branches, tertiary veins densely reticulate toward margins, black glands intramarginal (dense) and laminar (scattered).
blades linear-subulate, 4–11 × 0.4–0.8 mm, base articulated, persistent, parallel or slightly expanded, margins revolute, apex rounded with ± prominent hydathode to long-acuminate, midrib unbranched.
subcorymbiform to cylindric, 10–206(–600)-flowered, subsidiary branches narrowly ascending to curved-ascending.
± narrowly cylindric, 1–7-flowered, with 1(–3)-flowered dichasia from to 4 proximal nodes, rarely with 1 pair of flowering branches;
flowers sessile or nearly so.
8–15 mm diam.;
sepals not imbricate, erect in fruit, lanceolate or oblong-lanceolate to elliptic or ovate-elliptic, subequal, (1.5–)2–4 × 0.8–1.6 mm, apex acute to rounded;
petals pale yellow, oblanceolate to elliptic, 3–6(–9) mm;
stamens (20–)30–60;
anther gland black;
styles 1–4 mm.
10–14 mm diam.;
sepals deciduous, not enclosing capsule, 5, linear-subulate, unequal, 2–4 × 0.4–0.5 mm;
petals 5, bright yellow, oblanceolate-oblong to obovate, 5–10 mm;
stamens deciduous, 50–90;
ovary 3-merous.
ovoid to subglobose, 2.5–6 × 2–3.5(–4) mm, with longitudinal vittae or elongate to ovoid vesicles.
narrowly (sub-)cylindric, (4–)5.7–9.5 × 1.5–2 mm.
not carinate, 0.5–0.7 mm;
testa linear-reticulate.
scarcely carinate, 0.5 mm;
testa coarsely reticulate.
= 14, 16.
= 18.
Hypericum punctatum
Hypericum tenuifolium
Hypericum punctatum has been confused with H. pseudomaculatum; it can almost always be distinguished by style length and anther gland (black in H. punctatum, amber or pellucid in H. pseudomaculatum). D. E. Culwell’s (1970) record of one specimen of the latter from Missouri with a black anther gland could refer to a hybrid; he and other authors agree that such plants are rare, despite the considerable overlap in distribution of these species. Culwell remarked on the unexpected fecundity of the experimentally produced cross H. graveolens × punctatum but nowhere compared the resulting plants with H. ×mitchellianum, a probable hybrid with that parentage (see discussion
under H. ×mitchellianum. Both H. punctatum and H. ×mitchellianum (but not H. graveolens) display a ring of 16 chromosomes at meiosis, and Culwell suggested that this phenomenon may imply some degree of pseudogamy in the group. C. R. Bell (1965) recorded n = 7 chromosomes for this species; his illustration shows n = 8.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Hypericum tenuifolium differs from H. galioides in habit, leaf size, and inflorescence, and in its drier habitat. Its nonrooting stems, longer leaves, and (usually) longer stems distinguish it from H. lloydii.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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