Click the number at the start of a key lead to highlight both that lead and its corresponding lead. Click again to show only the two highlighted leads. Click a third time to return to the full key with the selected leads still highlighted.
Key to Hypericum
Hypericaceae
Hypericum
https://fsus.ncbg.unc.edu/main.php?pg=show-key.php&keyid=40053
2 Leaves without an articulation at the very base, the petiole merging gradually into the stem with no break, groove, or abrupt change in color or texture; plants herbs, decumbent shrubs, or shrubs.
5 Leaves spreading or ascending, generally multi-nerved, > 1 mm wide; inflorescence a dichasial cyme; herbs or shrubs.
6 Leaves 1.5-5 cm wide; shrubs; [exotics persistent and sparingly naturalizing from horticultural cultivation]
6 Leaves < 1.5 cm wide; shrubs, subshrubs, suffrutescent herbs, and herbs; [natives and exotics, collectively common and widespread]
10 Shrubs, decumbent shrubs, or suffruticose herbs; [section Myriandra, subsections Brathydium, Pseudobrathydium, and Suturosperma]
Key to Hypericum, Key A: shrubby St. John's-worts with needle-like leaves and flowers with 5 petals and 5 sepals [section Myriandra, subsection Centrosperma]
Copy permalink to share | Check for keys that lead to this key
https://fsus.ncbg.unc.edu/main.php?pg=show-key.php&keyid=40055
2 Upper leaf surface convex, merging gradually with revolute margins; leaves oblanceolate to linear-oblanceolate (“oblinear”); [east and west of the Mississippi River in the Coastal Plain]
3 Capsules 3-4.5 (-6) mm long; longest leaves 7-16 mm long; corollas 13-17 mm in diameter; seeds reddish-amber or brown, the alveoli not in distinct longitudinal rows, the seed lacking longitudinal ridges except for the two marginal sutures; primary branches with two ridged or winged angles running the length of the internodes, extending from the leaf midribs (but not the margins) at the base of the paired leaves; leaf surface glossy; [of alfisols and ultisols of wet pine savannas, flatwoods, and seepage bogs]
4 Plant usually branched near the base, becoming bushy and often forming a rather compact rounded shrub, usually less than 0.5 meter tall, rarely somewhat taller; inflorescence narrowly cylindric, from several of the upper stem nodes, with irregularly branched lateral clusters of flowers; seed medium to dark brown, the nearly circular alveolae not arranged in distinct lines; [SC south to north Florida and west to s MS and e. LA, usually in acidic wetland savannas and seepage slopes]
4 Plant usually unbranched in the lower 1/3 to 1/2 of main stem length, often relatively narrow and 0.5 to 1.5 meter tall; inflorescence usually terminal, or from only the upper one or two stem nodes, obconic in overall shape, the inflorescence appearing regularly dichotomously branched; seed dark brown to nearly black, the polygonal alveolae arranged in longitudinal lines; [peninsular FL and western Cuba, usually in calcareous Pinus densa savannas and wet marly grasslands]
3 Capsules 6-9 mm long; longest leaves 4-10 (-11); corollas 13-15 mm in diameter; seeds dark red to black, the alveoli in distinct longitudinal rows, with raised ridges often evident between the rows; primary branches with six ridged or winged angles running the length of the internodes, extending from the midribs and margins at the base of the paired leaves; leaf surface dull; [of seasonally dry spodosol pine flatwoods and interdune flats and hollows]
5 Plant a low shrub, <4 dm tall, more-or-less decumbent, forming dense clumps or patches; flowers 10-12 mm in diameter; inflorescence elongate (flowers at up to 5 nodes); [of dry to mesic soils of the lower Piedmont and inner Coastal Plain from sc. VA to ec. AL; disjunct to rock outcrops of the sc. GA Coastal Plain]
5 Plant an erect shrub, 5-40 dm tall, with single main stem branched above; flowers 13-26 mm diameter; inflorescence elongate (3-7 nodes) or short (1-3 nodes in H. fasciculatum and H. chapmanii); [of wet soils of the Coastal Plain].
6 Undersurface of most leaves easily visible (exposed) on both sides of the midrib, the veins usually obvious on the undersurface; leaves narrowly oblanceolate to linear-oblanceolate (“oblinear”), 1.5-5 (-7) mm wide; inflorescence elongate (3-7 nodes)
6 Undersurface usually not visible except for the midrib (leaf margins nearly touching the midrib for its entire length), if the undersurface visible then no veins visible; leaves linear, needle-like, 0.5-1.5 mm wide; inflorescence elongate or short.
8 Young branches, leaves, and sepals strongly glaucous; bark of upper stem and branches silvery gray and smooth; mature plant 2-4 m tall with ascending branches imparting a tree-like or vase-like aspect; [restricted to shores of sinkhole ponds in Bay and Washington Counties, FL Panhandle]
9 Inflorescence elongate (3-7 nodes); stem bark tight, thin, not exfoliating or exfoliating in narrow strips, grayish (not revealing buff or pale cinnamon color); leaf undersurface, if exposed at all, distinctly paler than the upper surface; [usually associated with flowing water (blackwater streams and impoundments)]
9 Inflorescence short (1-3 nodes); stem bark corky-thickened to spongy, exfoliating in broad strips or sheets revealing buff or pale cinnamon color; leaf undersurface, if exposed at all, about the same color as the upper surface; [usually associated with static water (Carolina bays, impoundments, beaver ponds, borrow pits, flatwoods depressions, cypress-gum ponds and stringers)].
10 Mature plant 2-3 (-4) m tall; branches ascending and imparting a tree-like or vase-like aspect (younger plants may be bushy); youngest internodes terete; [of flatwoods depressions and cypress-gum ponds and stringers of FL Panhandle only]
10 Mature plant 0.8-1.5 (-2) m tall; branches spreading and imparting a bushy or gumdrop aspect; youngest internodes with distinct winged ridge on either side; [of Carolina bays, impoundments, beaver ponds, borrow pits, widespread]
Key to Hypericum, Key B: shrubby St. John's-worts with 4 petals and 4 (rarely 2) sepals [section Myriandra, subsection Ascyrum]
Copy permalink to share | Check for keys that lead to this key
https://fsus.ncbg.unc.edu/main.php?pg=show-key.php&keyid=40056
2 Leaves rounded or subcordate at the base; [collectively widespread in our area].
3 Large outer sepals broadly rounded to obtuse at the apex; shrub solitary, 3-10 dm tall; bark of older stems reddish-brown, exfoliating in strips; [widespread in our area]
6 Erect shrub, usually with a single stem, freely branched well above ground level (or from ground level if injured, as by fire, but then the multiple branches still erect rather than decumbent), to 1 m or more tall; leaves usually variable in size and shape, widest near the middle
6 Decumbent, matted shrub, with several prostrate stems arising from a primary rootstock near ground level, each with numerous erect branchlets, rarely over 3 dm tall; leaves usually relatively uniform in size and shape, widest above the middle
Key to Hypericum, Key C: shrubby St. John's-worts with broader leaves (mostly lanceolate or oblanceolate) and flowers with 5 petals and 5 sepals
Copy permalink to share | Check for keys that lead to this key
https://fsus.ncbg.unc.edu/main.php?pg=show-key.php&keyid=40057
2 Leaves mostly narrowly oblanceolate, the larger 2-3 cm long, 2-5 (-7) mm wide, mostly 5-10× as long as wide; seeds 0.4-0.8 mm long, dark brown
2 Leaves mostly oblong, elliptic, narrowly elliptic, or broadly oblanceolate, the larger (2-) 3-7 cm long, 1-15 mm wide, mostly 2.5-7.5× as long as wide; seeds 0.8-1.5 mm long, amber to medium or dark brown.
5 Styles and carpels (3-) 5; mature capsule deeply lobed (with longitudinal deep grooves); sepals with 3-7 basal veins
Key to Hypericum, Key D: herbaceous St. John's-worts with leaves ascending or appressed, 1-nerved, < 1 mm wide and with a diffuse, racemose or dichasial inflorescence
Copy permalink to share | Check for keys that lead to this key
https://fsus.ncbg.unc.edu/main.php?pg=show-key.php&keyid=40058
1 Perennial herbs; inflorescence with dichasial branching (a compound cyme); plants with basal offshoots with decussate leaves 2-4 mm long and 0.2-0.4 mm wide; [endemic in Florida scrub in Highlands and Polk counties, FL]
1 Annual herbs; inflorescence with monochasial branching (a compound raceme); plants lacking basal offshoots; [collectively widespread].
2 Leaves scale-like, 1-5 mm long; capsules ca. 2-3× as long as the sepals; seeds minutely and inconspicuously reticulate; stamens 5-10
Key to Hypericum, Key E: herbaceous St. John's-worts with broad leaves, 3 (-4) locular capsules, stamens connate at base into 3 or 5 fascicles, leaves with black dots as well as translucent glands (except in H. perforatum), and sepals and/or petals marked with black dots or lines
Copy permalink to share | Check for keys that lead to this key
https://fsus.ncbg.unc.edu/main.php?pg=show-key.php&keyid=40059
1 Smaller stems strongly wing-angled; seeds 1.0-1.3 mm long; leaves of the main stem (8-) 11-20 (-26) mm long, those of the lateral branches typically much smaller; leaves punctate primarily with translucent glands, black glands few and restricted to the margins and occasionally in from the margins near the leaf tip; [exotic, usually in disturbed habitats]; [section Hypericum]
4 Styles (3.0-) 5.6-10.0 (-12.0) mm long; sepals without black lines; petals (5.0-) 11.5-16.1 (-18.0) mm long, without black lines and with round black glands only along the petal margin; longest stamens (8.0-) 10.7-16.3 (-22.0) mm long; cymes relatively few-flowered, (2-) 5-14 (-22) flowers per plant
Key to Hypericum, Key F: shrubby and subshrubby St. John's-worts
Copy permalink to share | Check for keys that lead to this key
https://fsus.ncbg.unc.edu/main.php?pg=show-key.php&keyid=40060
1 Plant a matted, decumbent shrub, 0.5-3 (rarely to 5) dm tall; leaves 1.5-2.5× as long as wide, without axillary fascicles of leaves; inflorescences of 1 (-5) flowers; [endemic to rock outcrops at moderate to high elevations in the Mountains of sw. NC, nw. SC, and ne. GA]; [section Myriandra, subsection Pseudobrathydium]
1 Plant an erect shrub or suffrutescent herb, 1.5-20 dm tall; leaves 1.5-5× as long as wide, with or without axillary fascicles of leaves; inflorescences of (1-) 3-70 flowers; [collectively widespread in our region, but not at moderate to high elevations in the s. Blue Ridge].
2 Leaves 5-15× as long as wide; stamens 120-200 or 45-85; plants 1.5-6 dm tall.
3 Stamens 120-200; leaves 20-35 mm long × 3-5 mm wide; seeds 1.5-1.8 mm long; [section Myriandra, subsection Brathydium]
3 Stamens 45-85; leaves 30-70 mm long × 3-15 mm wide; seeds 2.0-2.7 mm long; [section Myriandra, subsection Suturospermum]
2 Leaves 2-5× as long as wide; stamens 30-95; plants 4-20 dm tall; [section Myriandra, subsection Suturosperma].
4 Larger leaves 4-10 mm wide, 3-5× as long as wide; axillary leaf fascicles present in main leaf axils; seeds pale brown, faintly reticulate, 0.4-0.5 mm long
4 Larger leaves 10-30 mm wide, 1.5-3× as long as wide; axillary leaf fascicles absent; seeds dark brown, strongly reticulate, 1.5-2 mm long.
5 Flowers usually in many-flowered cymes terminating branches; sepals 1.5-2.0 mm long, usually triangular-acute; capsules ovoid to subglobose, 4-5 mm long (excluding the styles) and 4-5 mm broad; seeds 1.5-1.8 mm long, usually falcate-cylindric, dark purplish-brown and lustrous when mature
Key to Hypericum, Key G: herbaceous St. John's-worts with broad leaves, 1-locular capsules, stamens separate or connate at base, but not grouped into fascicles, leaves with translucent dots, without black dots, sepals and petals with translucent lines or dots only, not marked with black dots or lines
Copy permalink to share | Check for keys that lead to this key
https://fsus.ncbg.unc.edu/main.php?pg=show-key.php&keyid=40061
1 Stems and leaves glabrous.
2 Styles united, persistent as a single straight beak on the capsule; [section Myriandra, subsection Suturosperma].
2 Styles separate, more or less divergent, not persistent as a beak on the capsule; [section Trigynobrathys].
6 Punctate glands absent on the stem (rarely very few on the internodes of the inflorescence); punctate glands of the leaves small, round, distributed on the lower leaf surface, becoming sparse toward the base of the leaf and toward the midrib; midstem leaves mostly broadest at or beyond the middle
6 Punctate glands frequent on the stem; punctate glands of the leaves and stem large, oval, distributed evenly and densely on the lower leaf surface, also dense on the upper leaf surface in H. denticulatum and H. harperi (absent on upper leaf surface in H. species 1); midstem leaves usually broadest at or below the middle.
7 Upper surface of the leaf with no punctate glands; inflorescence branches typically with 3-12 pairs of bracteal leaves about 1/2 as large as the foliage leaves; [of shallow soil mats on granitic domes in the upper Piedmont of NC]
7 Upper surface of the leaf with abundant punctate glands; inflorescence branches with at most a few pairs of very small bracts; [of Coastal Plain wetlands, very rarely disjunct inland and then in wetlands].
8 Leaves 10-35 (-40) mm long, 3-8 (-12) mm wide, 3-10× as long as wide, lanceolate to linear-lanceolate, mostly ascending to spreading, often equaling the internodes; sepals 3.0-5.0 mm long, 0.8-2.5 mm wide, acute to acuminate; lanceolate to linear-lanceolate; upper portion of stem with numerous axillary branches; lower stem usually spongy-thickened with aerenchymatous tissue; [of upland depression ponds of the Coastal Plain, growing where seasonally inundated]
8 Leaves 5-20 (-24) mm long, 5-15 mm wide, 1.2-2.5× as long as wide, ovate to obovate to narrowly elliptic, mostly appressed to the stem, mostly shorter than the internodes; sepals 3.0-8.0 mm long, 1.5-4.0 mm wide, acute; lower stem not spongy-thickened with aerenchymatous tissue (or slightly so in H. erythreae); [of moist pinelands of the Coastal Plain, very rarely disjunct inland to bog habitats in the Piedmont and Mountains].
12 Sepals broadest near the base; inflorescence with few or no normally sized leaves, these only low in the inflorescence, giving the inflorescence a naked appearance.
12 Sepals broadest near the middle; inflorescence with many normally sized leaves and leaflike bracts, giving the inflorescence a leafy appearance.
15 Inflorescence branches from the upper 1-6 nodes of the stem, the further branching repeatedly monochasial; stem with apical internode well developed, usually longer than the internode below; sepals broader above the middle, more-or-less imbricate; [of the Coastal Plain]
15 Inflorescence branches from the upper 2-10 nodes of the stem, the further branching mostly dichasial; stem with apical internode shorter than the internode below or even essentially absent; sepals broader below the middle, not imbricate (rarely broader above the middle and imbricate); [widespread]