Gentian

Gentiana

While I tried to include most Gentians found in horticulture, additional species of potential in cold climates may be found on this external link.
http://www.efloras.org/florataxon.aspx?flora_id=120&taxon_id=113422

Gentiana acaulis ( Trumpet Gentian )
A short, dense, mat-forming, clumping, evergreen perennial, reaching up to 4 inches x 2 foot ( reports of 6 inches x 3.5 feet ), that is native to the European Alps from Spain to the Carpathians and Balkans.
The elliptic, basal leaves, up to 1 inch in length, form a basal rosette.
The foliage is glossy deep green.
The brilliant, deep blue ( with green spots ), bell-shaped flowers, up to 4 ( rarely over 2 ) inches in length, are borne during late spring into early summer.
Hardy zones 2 to 8 in full sun to partial shade on on moist, deep, acidic, fertile, humus-rich, very well drained soil. It does not enjoy sandy or very light soils.

* historic archive photos

* excellent photo link found on internet
http://plants.nature4stock.com/?page_id=2664

subsp clusii
Also called Gentian clusii. Similar but smaller, reaching up to 4 x 12 inches, with large, purplish-blue flowers.
Tolerant of limestone soils.

subsp dinarica
Similar except for having broader foliage and abundant flowers that are not spotted.
Tolerant of limestone soils.

Gentiana affinis ( Pleated Gentian )
A perennial, reaching up to 1.5 feet in height, that is native to moist prairies and marshland in northern North America ( from south-central British Columbia to south-central Northwest Territories to northwest Ontario; south to northern California to central Arizona to western Texas to South Dakota to central Minnesota ). It is endangered in Alberta, California, South Dakota and Minnesota.
The narrow lance-shaped to oblong leaves are up to 3 x 0.8 inches in size. The foliage is mid-green.
The intense mid-blue flowers, up to 1.5 inches long, are borne on upright racemes during mid to late summer.
Hardy zones 2 to 6 in full sun to partial shade on moist to wet, peaty or sandy soil.

Gentiana andrewsii ( Bottle Gentian )
A long-lived, upright, clumping perennial, reaching a maximum size of 3 x 2 ( rarely over 2 ) feet, that is native to moist meadows in North America ( from eastern Saskatchewan to Rainy River, Ontario to Duluth, Minnesota to Michigan's Upper Peninsula to Tobermory, Ontario to Belleville, Ontario to far southeast Quebec to New Hampshire; south to Nebraska to Missouri to northern Kentucky to Maryland ). It is recorded as growing in Calgary, Alberta though likely not native there. It is critically endangered in Saskatchewan, New York State and Maryland. In the Windsor/Essex County, Ontario region; it was abundant around Windsor, along the Detroit River, southern Essex County as well as the Ohio shore during the 1800s. It was also common at Detroit during that time.
The whorled, lance-shaped leaves, up to 6 x 1.5 inches in size, are luxuriant glossy deep green, turning to deep reddish-brown during autumn.
The intense deep blue flowers, up to 1.6 inches in length, are borne on dense terminal clusters during late summer to mid-autumn lasting a month of more.
Hardy zones 3 to 7 in full sun to partial shade on moist, fertile, humus-rich, acidic to neutral soil. Easy to grow. Seedlings often do not bloom until the 2nd or 3rd year. They can be transplanted during autumn or early spring. It is rarely bothered by insect pests or disease.

* historic archive photos

Gentiana angustifolia
A rosette-forming, evergreen perennial, reaching up to 4 inches x 1 foot, that is native to mountains in central Europe.
The lance-shaped leaves are mid-green.
The deep blue, trumpet-shaped flowers are borne during early summer.
Hardy zones 6 to 7 in full sun on light, well drained soil.

Gentiana asclepiadea ( Willow Gentian )
A very long-lived, arching, herbaceous, clumping perennial, reaching up to 3.3 x 3.3 ( often under 2 in height ) feet, that is native to Eurasia especially central and southern Europe.
The paired, tapered, lance-shaped to ovate leaves, up to 3.2 inches in length, are glossy bright to mid-green.
The deep blue to purplish-blue, narrow bell-shaped flowers are up to 2 ( rarely over 1.3 ) inches in length. They are borne from the leaf axils in clusters of 2 or 3, from mid-summer into autumn.
Hardy zones 5 to 9 in partial to full shade on moist, fertile, humus-rich, well drained soil. It is alkaline soil tolerant. Propagation is from seed, basal cuttings and division.

* historical archive photo

'Alba'
The flowers are white with a bright green throat. It is otherwise identical to the species.

Gentiana catesbaei ( Catesby's Gentian )
Also called Elliott's Gentian. A perennial, reaching up to 2.8 ( often under 1.5 ) feet in height, that is native to moist forests on the coastal plain from Delaware south to northern Florida. It is also found in central Alabama and around Marcus Hook, Pennsylvania.
The whorled lance-shaped to ovate leaves, up to 2.3 inches in length, are mid to deep green.
The deep blue flowers are borne on terminal clusters of up to 7 during early to mid-autumn ( rarely into early winter ).
Hardy zones 6b to 8b and is easily grown in full sun to partial shade on moist to wet , fertile, well drained soil.

* photo of unknown internet source

Gentiana clausa ( Closed Gentian )
Also called Bottle Gentian. A perennial, reaching a maximum size of 2.3 x 2 ( rarely over 1 ) feet, that is native to open, moist forests in eastern North America ( from Quebec south through the Appalachians into Tennessee and North Carolina ). Very rare to endangered in Maryland where it is only known from a few locations in Alleghany and Cecil Counties.
The paired, lance-shaped leaves, up to 5.5 inches in length, are luxuriant bright green.
The rich blue flowers are borne on dense terminal clusters during late summer to early autumn. They are never open completely, hence the name Closed Gentian.
Hardy zones 3 to 7 in partial shade on fertile, consistently moist, very well drained soil. They prefer cool summer climates, especially enjoying cool summer nights. It does not enjoy transplanting.

* photo taken on Aug 25 2013 @ University of Maryland, College Park

* photo taken by Robert H. Mohlenbrock @ USDA NRCS. 1995. Northeast wetland flora

Gentiana crinata ( Greater Fringed Gentian )
Also called Gentianopsis crinita. An upright biennial, reaching up to 2.3 x 1.3 ( rarely over 1.5 ) feet, that is native to riverbanks, swamps and moist prairie. It is native to eastern North America ( from central Saskatchewan to Quebec; south to North Dakota to central Iowa to central Indiana to western North Carolina to northern Delaware ). It is now rare in the wild due to habitat loss. It is endangered in North Dakota, Vermont, New Hampshire, Illinois, Maryland, Virginia, North Carolina and Georgia; extinct in the wild in West Virginia and Delaware.
The lance-shaped to ovate leaves are up to 2.5 x 1 inches in size. The foliage is mid-green above, yellowish-green beneath.
The purplish-blue flowers, up to 1.5 inches long, appear during late summer.
Hardy zones 3 to 6 in full sun on consistently moist to wet, neutral, sandy soil.

* historic archive photos

Gentiana cruciata
A vigorous, dense, compact perennial, reaching a maximum size of 16 inches x 1.5 feet, that is native to high mountains of central Europe, east to western Siberia, the Caucasus and northern Iran.
The leaves, up to 5 x 2 inches, form basal rosettes. The foliage is bright green.
The deep blue flowers, up to 1 inch long, are borne over a long season from mid-summer to early autumn. They attract hummingbirds and butterflies.
Hardy zones 3 to 7 in full sun to partial shade. It is unusually drought tolerant for a Gentian.

Gentiana dahurica
A perennial, reaching a maximum size of 16 inches x 2.5 feet.
The leaves are up to 12 inches in length. The foliage is glossy deep green. The stems are leafy.
The purplish-blue, tubular flowers are borne during late summer.
Hardy zones 3b to 7 in full sun to partial shade. It is easy to grow on acidic soils, however it does not enjoy alkaline soil.

Gentiana dinarica
A vigorous perennial, reaching a maximum size of 6 inches x 2 feet, that is native to Yugoslavia.
The showy, blue flowers are borne during late spring.
Hardy zones 3 to 7 in full sun to partial shade. It loves limestone soils.

Gentiana farrari
A prostrate perennial, reaching a maximum size of 4 inches x 1 foot, that is native to Tibet.
The leaves are very narrow. The intense, mid-blue ( throated white ) flowers, up to 2.4 inches in length, are borne during late summer into autumn.
Hardy zones 5 to 8 in full sun to partial shade on moist, fertile, humus-rich, very well drained soil. It is tolerant of alkaline soils.

Gentiana frigida
A low, upright but spreading perennial, reaching height of 6 inches, that is native to the Carpathian Alps in Europe.
The leaves are up to 3 inches in length.
The yellowish ( with blue stripes ), bell-shaped flowers are borne 1 to 3 at the stem tips during late summer.
Hardy zones 3 to 7 in full sun to partial shade.

Gentiana gracilipes
A rosette-forming, tufted perennial, reaching size of 1 foot x 16 + inches.
The linear leaves, up to 1.2 inches in length, are bright green.
The purplish-blue, bell-shaped flowers are borne atop arching stems, during mid to late summer.
Hardy zones 3 to 7 in full sun to partial shade on moist, acidic, fertile, humus-rich, very well drained soil. It does not enjoy alkaline soils.

'Alba'
Pure white flowers, otherwise identical.

Gentiana grombezewskii
An erect but spreading, tufted perennial, reaching a maximum height of 1.5 feet.
The leaves are up to 12 inches in length.
The yellow, tubular flowers are borne on terminal clusters during late summer.
Hardy zones 3 to 7 in full sun to partial shade.

Gentiana lutea ( Yellow Gentian )
A strong growing perennial, reaching a maximum size of 6.6 x 2 feet, that is native to mountainous areas in central and southern Europe.
The thick stems bear broad lance-shaped to elliptical leaves, up to 12 x 4.7 inches in size. The paired leaves are blue-green.
The bright yellow, starry flowers, up to 1 inch wide, are borne on dense whorls of up to 10. They are borne during mid to late summer.
Hardy zones 4 to 8 on full sun to partial shade on moist, fertile, humus-rich, well drained soil. It requires cool summers. Propagation is from seed, basal cuttings and division.

* historical archive photo

Gentiana makinoi ( Makinoi's Gentian )
A perennial, reaching up to 2 feet in height, that is native to Japan.
The bright blue to deep purplish-blue, tubular flowers are borne on a leafy stem during late summer into early autumn.
It requires consistently moist, acidic, well drained soil.

Gentiana paradoxa 'Blue Herold'
A perennial, reaching a maximum height of 2 feet. G. paradoxa is native to western Asia from Turkey to the western Caucasus Mountains.
The leaves are narrow.
The large, intense mid-blue flowers are borne late summer to early autumn.
Hardy zones 3 to 7 in full sun to partial shade on moist soil. It is easy to grow from seed and is lime tolerant.

Gentiana quinquefolia

* historic archive photo

Gentiana saponaria ( Soapwort Gentian )
A perennial, reaching up to 2.6 feet tall, that is native to eastern North America ( from northern Illinois to the Hudson River Valley & Long Island in New York; south to eastern Texas to far northern Florida ). It is endangered and highly scattered throughout most of its range. It is extinct in Michigan where it was once native to Berrien and Cass Counties in the southwest corner. It is critically endangered in Pennsylvania where it was once native across most of the southern tier of counties. It is now extinct in Lancaster Co. and most of the Philly & Pittsburgh metro areas. It is mostly found in swamps, wet meadows and moist open forest in the wild.
The oppositely-arranged to whorled, smooth-edged, lance-shaped or ovate leaves, up to 5 x 0.5 inches in size, are mid-green.
The rich blue ( rarely white ) flowers, up to 1.5 x 2 inches in size, are borne on dense, rounded clusters during late summer into mid-autumn.
Hardy zones 5 to 9 in light shade on moist to wet well drained soil.

Gentiana saxosa
A prostate perennial, reaching up to 8 inches x 1 foot, that is native to New Zealand.
The spatula-shaped leaves, up to 1.3 inches in length, are deep green.
The purple ( with white veins ), bell-shaped flowers are borne during summer.
Hardy zones 8 to 9

Gentiana scabra ( Fortune's Gentian )
A rarely seen but spectacular perennial for the landscape border. It can reach up to 3 ( rarely over 1.5 ) feet, and is native to mountain meadows in central and southern Japan.
The linear leaves, up to 6 x 1.2 inches in size, are bright green.
The trumpet-shaped, intense, blue ( rarely white or purple ) flowers, up to 2.3 inches long, are borne early to mid autumn.
Hardy zones 4 to 7, it is easy to grow in full sun on just about any well drained soil though preferring light and peaty. They are not prone to insect pests or disease.

* photos taken on Aug 30 2012 in Columbia, MD

‘Zuikorindo’
Forms a spreading clump, reaching only 6 inches in height, bearing deep pink flowers at the stem tips during early to mid autumn.

Gentiana septemfida ( Crested Gentian )
A dense, tufted, spreading, long-lived, evergreen perennial, reaching a maximum size of 20 inches x 2 feet ( rarely over 1 foot in height ), that is native to mountain meadows in the Caucasus in western Asia.
The pointed oval leaves, up to 1.7 inches in length, are mid-green above, bright green beneath.
The abundant, mid-blue to purplish-blue, bell-shaped flowers, up to 2 inches in length, are borne in clusters of up to 8 over a long season from mid-summer to early autumn.
Hardy zones 2 to 7 in full sun ( cool climates ) to partial shade on moist, acidic, fertile, humus-rich, very well drained soil. It is easy to grow, even from seed.

* photos of unknown internet source



Gentiana sino-ornata
A rapid spreading, spreading, carpet-forming perennial, reaching a maximum size of 8 x 18 inches, that is native to Tibet and western China. The stems will root as they spread.
The narrow lance-shaped leaves, up to 1.3 inches in length, form rosettes. The foliage is glossy deep green.
The abundant, intense blue, funnel-shaped flowers, up to 2 inches in length, are borne during autumn.
Hardy zones 5 to 8 in full sun to partial shade on moist, acidic, fertile, humus-rich, very well drained soil. It is easy to grow where the soil is acidic and the summers are cool. It does not enjoy hot humid summers.
Clumps should be divided every 2 to 3 years to propagate and maintain vigor.

'Alba'
The flowers are pure white, it is otherwise identical to the species.

'Angel's Wings'
The flowers are bright blue with white feathering and striping.
It is otherwise identical to the species.

var lagodechiana
Prostrate in habit, reaching a maximum size of 15 inches x 2 feet. It makes a great plant for the rock garden.
The intense mid-blue flowers are borne solitarily late summer to early autumn.
Hardy zones 2 to 7

Gentiana tibetica ( Tibetan Gentian )
A perennial, reaching a maximum height of 3 feet, that is native to the Himalayas.
The lance-shaped leaves are up to 12 x 2 inches in size. The foliage is mid-green.
The creamy-white or greenish flowers are densely borne on terminal racemes during late summer.
Hardy zones 5 to 7 in full sun to partial shade on humus-rich, well drained soil. It is more drought tolerant than most Gentians.

Gentiana triflora ( Clustered Gentian )
A leafy, upright perennial, reaching up to 3.3 ( rarely over 2.7 ) feet in height, that is native to swamps in eastern Asia ( from eastern Russia; south to Mongolia to Manchuria to Korea and northern Japan ). It is closely related to Gentiana andrewsii of North America.
The large, ovate leaves, up to 6 x 1 ( rarely over 4 x 0.8 ) inches in size, are luxuriant bright green.
The intense bright blue flowers, up to 2 inches long, are borne on clusters from late summer into early autumn.
Hardy zones 3 to 8 in full sun to partial shade on moist, humus-rich, acidic to neutral soil.

Gentiana 'True Blue'
A stiffly upright ( rare for Gentians ), clumping perennial, reaching up to 2.5 x 2 ( rarely over 1.5 x 1.5 ) feet, that is the hybrid between Gentiana makinoi & G. scabra.
The lance-shaped leaves are luxuriant glossy mid-green.
The large, intense deep blue flowers, up to 2 inches wide, appear from mid-summer until autumn frosts.
Hardy zones 4 to 8 in full sun to partial shade on just about any moist, fertile, well drained soil.

* photos taken on Sep 22 2020 in Columbia, MD

* photos taken on Oct 13 2020 in Columbia, MD

* photo taken on May 17 2021 in Columbia, MD

Gentiana verna ( Spring Gentian )
A prostrate, mat-forming, evergreen perennial, reaching up to 4 inches x 1 foot, that is native to the British Isles ( very rare and protected ) and the Alps in Europe where it is much more common.
The oval leaves, up to 1 inch in length, are bright green.
The intense blue, starry flowers, up to 1 inch across, are borne during early spring.
Hardy zones 4 to 9 in full sun to partial shade on on moist, fertile, humus-rich to sandy, very well drained soil. It requires cool summers. Propagate yearly from seed as plants are often short-lived.

'Alba'
Pure white flowers, otherwise identical.

subsp angulosa
Larger growing, reaching up to 4 inches x 1 foot, with tufts of shiny mid-green leaves, up to 0.8 inches in length. The flowers are borne during late spring. It is otherwise similar.