Hypericum mutilum L. var. latisepalum Fernald
Hypericum mutilum L. var. parviflorum (Willd.) Fernald
Hypericum mutilum L. Dwarf St. John’s-wort
Dwarf St. John's wort is native to portions of Europe and North America. Identification: Plants are 4-18″ (10-45 cm) tall, sometimes up to 2½′ (79 cm), heavily branched, with a shrublike habit. Branches may be 4-angled or smooth, tapering, and sometimes winged. Leaves are roughly oval in shape, and attached directly to the stem (sessile). They are opposite, unlobed, ½-1½″ (1.3-3.8 cm) long and ¼-¾″ (6.3-19 mm) across. Flowers are ¼″ (6.3 mm) in size, yellow or yellow-orange, with five petals and 5-15 stamens. Beneath the petals of each flower there are somtimes green bracts that are narrower but roughly the same length, one for each petal. Blooms from July to October. Fruits are 1/16-⅛″ (2-3.5 mm) in length. Medical: Hypericin, a component all in species of St. John's wort, has antidepressant properties. It can also cause photosensitivity if it is handled or ingested. Below is a comparison of some species of St. John’s wort: |
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Hypericum ellipticum |
You are here Hypericum mutilum |
Hypericum perforatum |
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Common Name | |||||||||||||||||||||||||||||
Plant | 8-20″ (20-50 cm) tall. Stems are hairless, somewhat 4-angled.< | 4-18″ (10-45 cm) tall, sometimes up to 2½′ (79 cm), heavily branched, with a shrublike habit. Branches may be 4-angled or smooth, tapering, and sometimes winged. | Less than 3′ (91 cm) in height. | ||||||||||||||||||||||||||
Flowers | Yellow, in clusters of 1 to a few at stem and branch tips. Each flower is ⅜-½″ (1-1.4 cm) around, with 5 yellow petals and 5 pale green sepals, a fountain of yellow stamens, and three styles fused into one in the center. (Rarely, the number of sepals and petals may be 4 or 6.) There are in excess of 100 stamens. Flowers appear from July to August. | ¼″ (6.3 mm) in size, yellow or yellow-orange, with five petals and 5-15 stamens. Beneath the petals of each flower there are somtimes green bracts that are narrower but roughly the same length, one for each petal. Blooms from July to October. | Bright yellow, star-shaped, with five petals and many yellow stamens about the length of the petals. Petals have serrated edges and small black dots on the serrations. Flowers are up to ⅞″ (2.5 cm) across. | ||||||||||||||||||||||||||
Leaves | ⅜-1½″ (1-4 cm) × ⅛-¾″ (3-20 mm), and elliptical-oblong in shape, generally rounded at leaf tips, and attached directly to the stem (sessile). | Roughly oval in shape, and attached directly to the stem (sessile). They are opposite, unlobed, ½-1½″ (1.3-3.8 cm) long and ¼-¾″ (6.3-19 mm) across. | Oval, about ⅜″ (1.2 cm) long, with smooth edges, occurring in opposing pairs. | ||||||||||||||||||||||||||
Fruit | Capsules are ⅛-3/16″ (4-6 mm) × ⅛-3/16″ (3.5-5 mm), ellipsoid, and rounded to a tip. | 1/16-⅛″ (2-3.5 mm) in length. | |||||||||||||||||||||||||||
Range/ Zones | |||||||||||||||||||||||||||||
Habitats | Sandy forest floodplains, sandy swamps, moist to wed sandy prairies; damp, sandy, acidic areas in general | ||||||||||||||||||||||||||||
Type | Wild | Wild | Wild | ||||||||||||||||||||||||||
Occurrence | Common, sometimes invasive |
Online References:
Southeastern Flora, the Southeastern U.S. Plant Identification Resource
The Lady Bird Johnson Wildflower Center
Hypericum mutilum L. var. latisepalum Fernald
Hypericum mutilum L. var. parviflorum (Willd.) Fernald
Hypericum mutilum description by Thomas H. Kent, last updated 5 Oct 2021.
Range: