Scientific Name:
Hypericum L., Sp. Pl. 783 (1753)
Vernacular Name(s):
Aaron's beard; goldflower; Saint John's wort

Shrubs, subshrubs, perennial herbs, or annuals, often with annual stems; containing resin or oil in schizogenous spaces or canals and sometimes black or red glands containing hypericin or pseudohypericin. Stems terete or quadrangular, sometimes angular, often with raised lines. Leaves simple, sessile or shortly petiolate, usually with pellucid glands, often dotted with black glands, margin usually entire, glabrous or occasionally with simple hairs. Inflorescences terminal, sometimes lateral, in panicles or cymes; flowers bisexual or unisexual, regular, hypogynous. Bracteoles often inserted below calyx. Sepals usually 5, sometimes 4. Petals usually 5, sometimes 4, free, contorted in bud, golden to lemon yellow, abaxially sometimes tinged red, often oblique. Stamens usually connate at base in 3, 4 or 5 bundles, sometimes antipetalous; anther dehiscence longitudinal. Ovary superior, 3–5-loculed with axile placentae, or 1-loculed with parietal placentae, each placenta with 2–many ovules; styles usually 3–5, sometimes free or partly to completely united. Fruit usually a septicidal capsule, valves often with oil-containing vesicles; sometimes baccate. Seeds oblong or cylindric, often carinate or narrowly unilaterally winged.

1Black glands absent from stems, leaves, sepals and petals, or rarely present on leaves but then only in small groups; styles 3 or 52
Black glands present on stems, leaves, sepals or petals; styles 313
2Flowers and capsules with 5 styles3
Flowers and capsules with 3 styles5
3Low shrub, rhizomatous, rhizomes strong and well-developed; stems quadrangular, 4-lined; leaves sessile, reticulate tertiary veins visible; corolla 60–90 mm diam.; seed not wingedcalycinum
Upright to spreading shrub, not rhizomatous; stems and branches terete or flattened with 2 ± raised edges; leaves with petiole 0.5–3.0 mm long, reticulate tertiary veins not visible; corolla 40–70 mm diam.; seed narrowly winged4
4Sepal apex obtuse or rounded; stamens ⅓–½ length of petalshenryi
Sepal apex acute or acuminate; stamens ⅔–¾ length of petalskouytchense
5Shrubs or subshrubs; stems terete and 2-lined, flattened or compressed6
Subshrubs or herbs, often woody at base; stems quadrangular8
6Stems flattened or compressed; leaves lanceolate or oblong-lanceolate, 5–16 mm wide, apex acute and with 0.3–0.5 mm long mucro; petals persistent after anthesis; fruit a dry and dehiscent capsulecanariense
Stems terete and 2-lined; leaves ovate, ovate-elliptic, ovate-oblong, narrowly ovate, 9–40 mm wide, apex subacute, obtuse or rounded, sometimes with a < 0.1 mm mucro; petals caducous after anthesis; fruit ± succulent, indehiscent or dehiscent7
7Leaves without reticulate tertiary veins; petals 8–10 mm long, equal or slightly longer than sepals; stamens 6.5–11.0 mm long; styles 2.5–4.0 mm long; fruit indehiscent, red, becoming blackandrosaemum
Leaves with reticulate tertiary veins; petals 20–22 mm long, much longer than sepals; stamens 10.0–23.0 mm long; styles 12.0–12.5 mm long; fruit ± dehiscent, remaining red×inodorum
8Stems prostrate to decumbent, plant < 50 mm high, unless stems trailing through other vegetation; leaves 1.0–10.0 mm long9
Stems erect, plants usually > 100 mm high; leaves 2.5–33.0 mm long11
9Stems not rhizomatous; leaf margins strongly sinuate, light green to yellow-greenpusillum
Stems often rhizomatous; leaves usually planar or occasionally slightly sinuate, grey-green to olive-green, often entirely ruddy, usually ruddy on margin and distally10
10Leaves 1.5–4.5 mm long, 0.3–1.2 mm wide; flowers up to 6 mm diam.; sepals 1.7–2.8 mm long, 0.6–1.0 mm wide; petals 2.0–3.3 mm long, 0.9–1.2 mm wide; capsule 2.3–2.9 mm long; seed longitudinal ribs absent or weakminutiflorum
Leaves 1.0–10.0 mm long, 0.5–5.5 mm wide; flowers up to 11.0 mm diam.; sepals 2.5–5.0 mm long, 1.0–2.3 mm wide; petals 2.8–5.8 mm long, 2.0–3.5 mm wide; capsule 2.8–3.5 mm long; seed longitudinal ribs usually distinctrubicundulum
11Stems usually solitary, from decumbent and rooting base, usually branched only in upper half; leaves up to 33 mm long, up to 13.0 mm wide; capsule oblong-ellipsoid, wall thin and seed outline visiblemutilum
Stems usually several, from woody stock at base of plant, branched at base or along stem; leaves up to 20 mm long, up to 6.8 mm wide; capsule ovoid, wall coriaceous and seed outline not visible12
12Stems unbranched or branching from base; inflorescences terminal dichasial cymes; stamens 30–43; capsule 5.0–9.5 mm long, conspicuously protruding beyond the sepalsinvolutum
Stems branching along their length; inflorescences terminal and lateral mostly monochasial cymes; stamens 9–15; capsule 4.8–6.0 mm long, barely protruding beyond the sepalsgramineum
13Stems quadrangular and 4-linedtetrapterum
Stems terete and 2-lined or terete and without lines14
14Stems terete and lacking lines15
Stems terete and 2-lined16
15Leaves 20–60 mm long, with very short hairs below, with intramarginal black glands; sepals lanceolate-oblong, apex acute, margin with prominent black-glandular teeth; anther gland blackmontanum
Leaves 4–25 mm long, glabrous below, without black glands; sepals obovate, broadly elliptic or suborbicular, apex obtuse or rounded, margin with small black glands; anther gland orangepulchrum
16Stems lines with black glands; sepals narrowly lanceolate; capsule with vesicular glandsperforatum
Stem lines without black glands; sepals broadly elliptic, broadly elliptic-ovate, elliptic-ovate, ovate, elliptic, elliptic-oblong, capsule without vescicular glands17
17Sepals usually without black glands; petals > 12 mm long; anther gland blackolympicum
Sepals with conspicuous black glands; petals < 10 mm long; anther gland orange or orange-brown18
18Stems decumbent to prostrate; leaves broadly ovate, elliptic-lanceolate, lanceolate, ovate-elliptic or elliptic-oblong; sepals unequal, apex subacute or obtuse, margin entire or with a few sessile intramarginal and/or marginal black glands; capsule slightly exceeding sepalshumifusum
Main stems erect or upright, sometimes with decumbent lateral stems; leaves linear-lanceolate, linear-ovate, or narrowly oblong-lanceolate; sepals usually equal, apex acute, margin fringed with stalked black glands; capsule about 2 times length of sepalslinariifolium

About 460 species; almost cosmopolitan except for polar and desert areas and most of lowland tropics. Three species indigenous and two species endemic to New Zealand, and 14 naturalised species.

Indigenous (Non-endemic)
Number of species and named hybrids in New Zealand within Hypericum L.
Indigenous (Endemic)2
Indigenous (Non-endemic)2
Exotic: Fully Naturalised12
Exotic: Casual2
Origin uncertain: Present in wild1

Treatment of the native species follows Heenan (2008, 2011). In addition to the species treated here, other species and cultivars are grown in New Zealand as shrubs or rock garden plants. The petals of Hypericum spp. are liable to shrink when dried unless precautions are taken.

Connor, H.E. 1977: The Poisonous Plants in New Zealand. Edition 2. Government Printer, Wellington.
Heenan, P.B. 2008: Three newly recognised species of Hypericum (Clusiaceae) from New Zealand. New Zealand Journal of Botany 46: 547–558.
Heenan, P.B. 2011: Taxonomic notes on the New Zealand flora: Hypericum gramineum and Hypericum involutum (Hypericaceae). New Zealand Journal of Botany 49(1): 133–139.
Heenan, P.B. 2014: Hypericaceae. In: Breitwieser, I.; Brownsey, P.J.; Heenan, P.B.; Wilton, A.D. (ed.) Flora of New Zealand — Seed Plants. Fascicle 1. Manaaki Whenua Press, Lincoln.
Linnaeus, C. 1753: Species Plantarum. Impensis Laurentii Salvii, Stockholm.
Mabberley, D.J. 2008: Mabberley's plant book, a portable dictionary of plants, their classification and uses. Edition 3. Cambridge University Press.
Robson, N.K.B. 1972: Notes on Malesian Species of Hypericum (Guttiferae). Blumea 20: 251–274.
Robson, N.K.B. 1990: Studies in the genus Hypericum L. (Guttiferae) 8. Sections 29. Brathys (part 2) and 30. Trigynobrathys. Bulletin of the British Museum (Natural History). Botany 20: 1–151.