Hypericum mutilum |
Hypericum tenuifolium |
|||||
---|---|---|---|---|---|---|
dwarf St. John's-wort, small Canadian St. John's-wort, small flower st john's wort |
Atlantic St. John's-wort |
|||||
Habit | Herbs annual or perennial, usually erect, sometimes decumbent and rooting, basal branches sometimes present, usually with to 10 pairs of spreading branches distal to middle, 0.5–8 dm. | Shrubs, usually decumbent, not rooting, forming mats, 1–5 dm. | ||||
Stems | internodes 4-angled. |
internodes 6-lined at first, becoming 4-lined, then terete. |
||||
Leaves | spreading, sessile or amplexicaul; blade paler abaxially, ovate, elliptic, or elliptic-oblong (proximal), ovate or suborbiculate to elliptic or lanceolate (mid and distal), 3–27(–40) × 1–15 mm, papery to membranous, margins plane, apex obtuse to rounded, basal veins 3–5, midrib with to 3 pairs of branches. |
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. |
||||
Inflorescences | cylindric, 5–60-flowered, branching mostly dichasial; bracts linear-subulate. |
± 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. |
||||
Flowers | 3–5 mm diam.; sepals lanceolate to linear-lanceolate or elliptic-oblong to oblanceolate, equal or unequal, 2–4.5 × 0.6–1.5 mm, margins sometimes ciliate, not setulose-ciliate, apex usually acute to apiculate, sometimes obtuse to rounded; petals pale yellow, oblong, 1.7–3.5 mm; stamens 5–16, scarcely grouped; styles 0.5 mm; stigmas broadly capitate. |
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. |
||||
Capsules | narrowly ovoid to cylindric-ellipsoid, 2–5 × 1.6–2.4 mm, usually broadest at or near middle. |
narrowly (sub-)cylindric, (4–)5.7–9.5 × 1.5–2 mm. |
||||
Seeds | 0.4–0.7 mm; testa finely linear-scalariform. |
scarcely carinate, 0.5 mm; testa coarsely reticulate. |
||||
2n | = 18. |
|||||
Hypericum mutilum |
Hypericum tenuifolium |
|||||
Phenology | Flowering spring–mid summer (Apr–Jul). | |||||
Habitat | Dry, sandy woods, dunes and dune hollows, coastal plain | |||||
Elevation | 0–200 m (0–700 ft) | |||||
Distribution |
AL; AR; CA; CO; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MO; MS; NC; NE; NH; NJ; NY; OH; OK; OR; PA; RI; SC; TN; TX; UT; VA; VT; WA; WI; WV; BC; NB; NS; ON; QC; SK [Introduced in w North America]
|
AL; FL; GA; NC; SC
|
||||
Discussion | Subspecies 2 (2 in the flora). (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.) |
||||
Key |
|
|||||
Source | FNA vol. 6, p. 93. | FNA vol. 6, p. 79. | ||||
Parent taxa | Hypericaceae > Hypericum > sect. Brathys | Hypericaceae > Hypericum > sect. Myriandra | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Sarothra mutila | H. fasciculatum var. laxifolium, H. reductum | ||||
Name authority | Linnaeus: Sp. Pl. 2: 787. (1753) | Pursh: Fl. Amer. Sept. 2: 377. (1813) | ||||
Web links |
|