Bottle gentian | The Morton Arboretum

Family (English) Gentian
Family (botanic) Gentianaceae
Tree or plant type Perennial
Native locale Chicago area, Illinois, North America
Size range Medium plant (12-24 inches)
Light exposure Partial sun / shade (4-6 hrs light daily), Full shade (4 hrs or less of light daily)
Hardiness zones Zone 3, Zone 4, Zone 5 (Northern Illinois), Zone 6 (City of Chicago), Zone 7
Soil preference Acid soil, Moist, well-drained soil
Tolerances Occasional flooding, Wet sites
Season of interest late summer, early fall, mid fall
Flower color and fragrance Blue, Purple, White
Shape or form Narrow, Upright
Growth rate Moderate
Wildlife Insect pollinators
More information
Unique clusters of tubular, bluish-purple to violet flowers appear above the leafy foliage of bottle gentian from late summer to mid-fall. Preferring moist, shady conditions, bottle gentian can be planted in shade gardens, cottage gardens, woodland gardens, near ponds, and along streams. This species is native to the Chicago region according to Swink and Wilhelm’s Plants of the Chicago Region and current research.

Size and method of spreading:

At maturity, bottle gentian is 1 to 2 feet tall and 1 to 1 ½ feet wide. The plants inconsistently spread by self-seeding.

Native geographic location and habitat: (include C-value if appropriate)

The native range of bottle gentian includes the Northeast and North Central United States. C Value: 9.

Attracts birds or pollinators:

Bumblebees are attracted to the flowers of bottle gentian.

Leaf description:

The leaves of bottle gentian are wide at the base, then narrow to a pointed tip. They are ovate to narrowly lanceolate in shape and can be up to 4 ½ inches long and 2 inches wide. As they ascend the stems, the leaves increase in size. The leaves primarily occur in opposite pairs, but are whorled under the flower clusters. The leaves attach directly to the stem without stalks (sessile). The edges of the leaves are smooth (entire) or have a short fringe of hair (ciliate). The upper surfaces of the leaves are shiny, and both the upper and lower surfaces are hairless (glabrous). The main veins run parallel to the edges of the leaves.

Flower description:

Bottle gentian flowers never appear to open. They appear as 1 to 1 ½ inch long, inflated, pleated flower buds, even at maturity. They grow in terminal clusters or in smaller clusters in the upper leaf axils. The flowers are bluish-purple to violet in color. The petal-like structure (corolla) is tubular and has five small, slightly pointed to triangular lobes at the tip. A leaflike, tubular structure (calyx) surrounds the base of the corolla and splits into five, spreading, long, narrow (lanceolate) lobes.

Fruit description:

The fruit of bottle gentian are a similar size to the mature flowers, approximately 1 inch long. The tubular corolla persists around the fruit, forming a papery layer. The dry fruit longitudinally splits into two parts at maturity (capsules).