Broad-leaved Hellebore
Epipactis hellebore
Orchid family (Orchidaceae)

Description: This is a herbaceous perennial plant that is 10-32" (25-80 cm.) tall. The central stem is light green, terete, unbranched, and more or less pubescent. Along this stem, there are 3-10 alternate leaves. These leaves are 2-6½" (5-18 cm.) long and about one-third as much across; they are ovate, sessile (clasping the stem), light to medium green, glabrous (or nearly so), smooth along their magins, and parallel-veined, becoming gradually smaller as they ascend the stem. The inflorescence consists of a spike-like raceme of 10-50 flowers that is often one-sided. The central stalk of the inflorescence is similarly in appearance to the stem below. Individual flowers have a pedicel up to 6 mm. long, from which each flower is held laterally or nods downward slightly. At the base of each pedicel, there is a linear leafy bract that tapers gradually to a point; these floral bracts are ½-2" long, light to medium green, smooth along their margins, and hairless or slightly pubescent.

Each flower of this orchid is ¾-1" across, consisting of 3 sepals, 3 petals, and a reproductive column; the individual sepals are 10-12 mm. The 2 lower lateral sepals are ovate, while the upper sepal is oval-obovate and curved so it can function as a hood. The upper lateral petals are 8-12 mm. long and ovate, while the lowest petal is 10-14 mm. long and forms the lip of the flower. This lip forms a pouch that is maroon or dark purple inside, after which it contracts with upward turned margins, only to partially flatten out again and form a landing pad for visiting insects. The colors of the sepals and petals can be highly variable. The sepals are light green to pink with prominent central veins, while the petals are greenish white, pink, or purple; the colors of the sepals and petals tend to fade away with age. The short reproductive column is pale to bright yellow, while the nectar gland below is light green or white. The blooming period can occur from early summer to mid-autumn, but it typically lasts only 2-4 weeks. A faint vanilla fragrance may be detectable. Afterward, fertile flowers are replaced by seed capsules that are 10-16 mm. long, light green, pubescent, and angular-obovoid; they nod laterally. When the capsules are mature, they turn brown and split open to release the tiny seeds to the wind. The root system is fibrous and short-rhizomatous, sometimes forming clonal offsets.

Cultivation: The preference partial sun, dappled sunlight, or light shade, moist to mesic conditions, and soil containing loam, clay-loam, or rocky material. This plant can vary considerably in size depending on the fertility of the soil and moisture levels.

Range & Habitat: Broad-leaved Hellebore has naturalized mostly in the NE section of Illinois (see Distribution Map), while it is largely absent elsewhere. This orchid was introduced from Europe as a medicinal plant. It escaped from cultivation as early as the late 19th century. Habitats include mixed woodlands (coniferous and deciduous), woodland openings, woodland borders, thickets, roadsides, quarries, gravel pits, mine tailings, railway embankments, cemeteries, town parks, and garden-like settings. This plant prefers human-disturbed habitats in and around cities. Sometimes Broad-leaved Hellebore is cultivated in gardens, from which it can escape.

Faunal Associations: In Europe, the flower nectar of Broad-leaved Hellebore attracts social wasps (Vespidae), flower flies (Syrphidae), mosquitos, blow flies (Calliphoridae), honeybees and other bees, ants, and soldier beetles (Cantharidae); see Rewicz et al. (2017). In North America, information is more limited, but a social wasp, the American Yellowjacket (Vespula alascensis), visits the flowers of this orchid (Luer, 1975). It was originally misidentified as a European wasp, the European Yellowjacket (Vespula vulgaris). Insects that feed destructively on this orchid include a weevil (Stethobaris ovata) that feeds on the flowers and immature seed capsules, the larvae of a fly (Parallelomma vittatum) that mines the leaves of this orchid, and a thrips (Ctenothrips bridwelli); see Light & MacConaill (2011), St. Hilare (2002), and Howden (1995). Broad-leaved Hellebore is also probably eaten by some mammalian herbivores, such as the White-tailed Deer and Cottontail Rabbit.

Photographic Location: The photographs were taken at a flower garden in east-central Illinois.

Comments: Broad-leaved Hellebore is the only non-native orchid that has naturalized in Illinois. It is widely regarded as one of the more weedy orchids. One reason for its reproductive success and ability to naturalize in even disturbed habitats is related to its ability to utilize more than 60 distinct groups of mycorrhizal fungi. The presence of such fungi are required if an orchid seedling is to survive. In contrast, many orchids can utilize only one or a small number of such fungi for their seedlings. Another reason for this orchid's success is related to its ability to lure insects to its flowers by using deception. Its nectar contains aphid-alarm pheromones and green-leaf volatiles that lure predatory insects (like wasps) to the flowers, where they will search for herbivorous insects that are edible. In addition to these allurements, the nectar of Broad-leaved Hellebore contains opioids and alcohol, which causes flower-visiting insects to become intoxicated. As a result, they tend to hang around longer, increasing the probability that they will successfully pollinate the flowers (Candeias, accessed 2025).

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