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updated: 01/19/11 

Morphology of gentians Voyria

Gentians are very variable in their morphology. Listed below are some traits that occur in the family and their occurrence in some genera. Bibliographic references are listed in parenthesis [ ] after the characters. More information on most of these characters are available in Struwe et al. (2002).

See anatomy page for Anatomy, Palynology, Embryology, and Chemistry characters.

Habit (growth habit, trophy)

Roots, hairs, stems 

Leaves (petioles, stipules) 

Inflorescence (branching, position, bracts)

Flowers (see also Flower anatomy)

Calyx (sepals; see also Flower anatomy)

Corolla (petals; see also Flower anatomy)

Glands in the flower (see also Flower anatomy)

Stamens (androecium, filaments, anthers; see also Flower anatomy)

Gynoecium (pistil, ovary, style, stigma; see also Flower anatomy)

Fruits (see also Flower anatomy)

Seeds (see also Embryology)

Habit (growth habit, trophy):


trees: e.g., Anthocleista, Chorisepalum, Fagraea, Macrocarpaea, Potalia, Prepusa, Symbolanthus


shrubs: e.g., Adenolisianthus, Chorisepalum, Gentianothamnus, Fagraea, Ixanthus, Macrocarpaea, Orphium, Potalia, Prepusa, Saccifolium, Symbolanthus, Tachia


woody lianas and climbers: e.g., Anthocleista spp., Lagenanthus, Purdieanthus

herbaceous climbers: e.g., Bisgoeppertia, Crawfurdia


herbs: most gentians


single-stemmed trees and shrubs (monocarpic): Potalia


candelabra-shaped branching: Anthocleista spp.


leaves crowded at branch apices: many in subtribe Potaliinae and tribe Helieae


autotrophic plants: most gentians


heterotrophic plants, mycotrophs, saprophytes: Bartonia (partly heterotrophic), Cotylanthera, Obolaria (partly heterotrophic), Sebaea oligantha, Voyria, Voyriella


dioecious plants (male and female flowers on separate plants): Gentianella spp., Veratrilla. All other gentians have flowers that have fully functional male (stamens) and female (gynoecium) parts in the same flower.


prostrate habit (horizontal branching on the ground, rooting at the nodes): Exacum spp.


Roots, hairs, stems:


taproots: most gentians


coralloid roots, bird's nest roots (associated with mycorrhiza): Obolaria, Voyria, Voyriella


glabrous plants (lacking hairs): most gentians


hairy plants: Chironia spp., Macrocarpaea spp., Microrphium, Ornichia, Orphium


glandular hairs:

glaucous plants (with a waxy, bluegreen surface layer): Blackstonia, Eustoma


viscid plants (sticky): Ixanthus


bristles on vegetative parts (hard, sharp hairs): Microrphium, Orphium


corky bark: Saccifolium


hollow stems: common


terete (round) stems: common


quadrangular (4-cornered) stems: common

winged stems: common


Leaves (petioles, stipules):  

opposite leaves (leaves 2 and 2 along stem): nearly all gentians


alternate leaves (leaves single along stem): Saccifolium, Voyriella spp.


whorled leaves (verticillate, 3 or more together along stem): Curtia spp., Exacum spp.


leaves in basal rosette (rosulate): many gentians, especially in Chironieae and Gentianeae, e.g., Centaurium spp., Gentianella spp.

amplexicaul/perfoliate leaves (opposite leaves that are fused together at their bases): Exacum spp., Prepusa spp., Symphyllophyton, Tachiadenus spp.


saccate leaves (sack-shaped): Saccifolium


entire leaves (margin smooth, not lobed or dissected): all gentians (except Irlbachia poeppigii and some Fagraea)


dentate leaves (margin with teeth): Fagraea spp., Irlbachia poeppigii


scale-like leaves (leaves very small, like scales): Bartonia, Cotylanthera, Sebaea oligantha, Voyria, and Voyriella


interpetiolar line (ridge between the base of a pair of leaves): most gentians


interpetiolar stipules (a flap of leaf-like tisse between a pair of leaves): Macrocarpaea spp., very rare in the family, only occurs in one species


interpetiolar sheath ( a ring of tissue around the stem at the base of a pair of leaves): Anthocleista, Chorisepalum, Fagraea, Lisianthius, Macrocarpaea, Potalia 


auricules at base of leaves (ear-shaped appendages at the base of a leaf): Anthocleista spp., Fagraea spp.


axillary spines (spines in the leaf axil): Anthocleista

acrodromous leaf venation (arcuate, few veins, bent towards apex of leaf): common


brochidromous leaf venation (pinnate, veins straight towards edge of leaf): common in some genera, e.g., Anthocleista, Macrocarpaea spp., Fagraea


Inflorescence (branching, position, bracts):

axillary inflorescences (in leaf axils): many gentians, e.g.,  Enicostema, Saccifolium, Tachia, Zonanthus

terminal inflorescences (at top of branch): many gentians


solitary flowers (flowers one by one, not together): Cotylanthera, Gentianothamnus, Saccifolium

cymes (a type of inflorescence with a top flower and side branches that repetitive branch sideways, symmetrically or assymmetrically): most gentians


racemes: Fagraea spp.


capitate (flowers in tight heads): Cracosna, Tapeinostemon spp.


spicate (flowers in a spike): Coutoubea


cymes with monochasial branches (branches that only branch on one side, giving the appearance of one long branch with many flowers on one side): Chelonanthus, Irlbachia, Symbolanthus


flowers sessile (flowers without flower stalk, sitting directly on stem): Tachia, Tapeinostemon sessiliflorum, many in subtribe Faroinae


bracts and bracteoles scale-like, small (bracts are the small leaves in the inflorescence, often occur in pairs): most gentians


bracts leaf-like: Macrocarpaea


bracts perfoliate (a pair of bracts that are fused together at their base) : Ixanthus


extra bracts (more than 2) below flower or inflorescence: Fagraea spp.



Flowers (see also Flower anatomy):


3-merous flowers (3 calyx lobes, 3 corolla lobes, 3 stamens): Pycnosphaera (rarely in Enicostema)


4-merous flowers: many gentians, e.g., Canscora, Centaurium spp., Cicendia, Congolanthus, Coutoubea, Cracosna, Djaloniella, Exaculum, Faroa, Geniostemon, Hoppea, Ixanthus [also 5-merous], Karina, Neurotheca, Oreonesion, Sabatia spp., Schinziella (rarely in Enicostema)


5-merous flowers: most gentians


6-merous corolla: Chorisepalum, Blackstonia spp., Prepusa, Senaea (occasionally 6-7 also in some other genera: Enicostema, Gentiana, Irlbachia).


8-16-merous corolla and stamens: Anthocleista (10-16), Blackstonia (6-12), Potalia (8-10), Sabatia (4-5, 8-13), Urogentias (8)


2 sepals, 4 petals, 4 stamens: Cracosna, Obolaria


2 sepal lobes, 5 petals, 5 stamens: Microrphium


3 sepals, 4 petals, 4 stamens: Cracosna


4 sepals, 6 petals, 6 stamens: Chorisepalum


4 sepals, 8-16 petals, 8-16 stamens: Anthocleista, Potalia

hypogynous (ovary superior): all gentians


unisexual flowers: Veratrilla and Gentianella spp.


heterostylous flowers: only in tribe Saccifolieae, e.g., Curtia, Hockinia, Tapeinostemon spp., Voyriella [Knoblauch, 1895]


cleistogamous: Sebaea oligantha only

actinomorphic (radially symmetric) flowers: most gentians

Symbolanthus zygomorphic (bilaterally symmetric) flowers: see zygomorphy under calyx, corolla, and stamens below
Gentiana erect flowers (upright on the plant): many gentians
horizontal flowers (sideways): many gentians

nodding flowers (hanging down): Crawfurdia, Lagenanthus, Lehmanniella, Lisianthius, Purdieanthus


Calyx (sepals; see also Flower anatomy):

fused sepals (at least at base of calyx): most gentians


free sepals: Anthocleista, Chorisepalum, Potalia


actinomorphic (symmetrical) calyx: most gentians


zygomorphic (bilateral) calyx: Exacum spp., Frasera

wing (lower picture) or keel (upper picture) on back of sepals: Canscora spp., Cicendia, Exacum spp., Schultesia spp., Symbolanthus spp., Tachia spp., Tachiadenus spp.
Wings are very thin; keels are thicker at the base.

dorsally thickened sepals: many in tribe Helieae, many also have wings or keels


membranaceous sepals (paper-thin): Prepusa


sepals deciduous (fall off) in fruiting stage: Chorisepalum, Macrocarpaea, Tachia


yellow-orange calyx: Potalia


imbricate calyx lobes in bud: common


decussate calyx lobes in bud: Anthocleista, Chorisepalum, Potalia


membrane between calyx lobes (intracalycine membrane: Crawfurdia spp., Gentiana spp.


Corolla (petals; see also Flower anatomy):


fused petals (sympetaly): all gentians  are at least fused at the very base of the petals


actinomorphic corollas (symmetric, all lobes equal): most gentians


slightly zygomorphic corollas (not symmetric, lobes unequal) : e.g., Canscora spp., Chelonanthus spp., Symbolanthus spp.

rotate corollas (deeply divided, only fused at base, lobes spreading widely): e.g., Frasera, Swertia


tubular corollas (straight tube, lobes straight): e.g., Potalia spp.

salvershaped corollas (like a trumpet, narrow tube and flaring lobes): e.g., Lisianthius spp., Symbolanthus spp., Tachia spp., Tachiadenus


funnelshaped corollas (like a funnel, narrow tube and lobes spreading, but not flaring): e.g., Chelonanthus, Gentianothamnus, Symbolanthus spp., Tetrapollinia


bellshaped corollas (campanulate):

Gentiana tubular corollas that never open: Gentiana spp. (bottle gentians) are forced open by bumblebees for pollination, the flowers never open by themselves (see Pollination)

contort corolla lobes in bud (all lobes twisted and overlapping in bud): most gentians


imbricate corolla lobes in bud (lobes overlapping except two, one inner and one outer): Bartonia, Obolaria, Saccifolium only


valvate+contort corolla lobes in bud (valvate = lobes not overlapping, only sitting edge to edge): Aripuana only

petal edges erose (papillate): common in many genera

petal edges ciliate or dentate (with hairs or teeth along edge): Gentianopsis, Pterygocalyx


fimbriae (hairs) at the base of the corolla lobes: Comastoma, Gentiana, Gentianella spp.


folds (plicae) between corolla lobes (thinner folded tissue fusing corolla lobes): Crawfurdia, Gentiana spp., Metagentiana, Tripterospermum


each petal with a spur (a thin, long and hollow structure attached to a petal): Halenia only


white petals: e.g., Anthocleista, Coutoubea, Enicostema, Irlbachia spp., Fagraea spp., Saccifolium, Symbolanthus spp., Tachiadenus spp.


yellow petals: e.g., Blackstonia spp., Ixanthus spp., Sebaea spp., 


orange petals: e.g., Lagenanthus spp., Tapeinostemon spp., 


red petals: e.g., Gentianella spp., Rogersonanthus spp., Symbolanthus spp.


pink petals: e.g., Centaurium spp., Sabatia, Symbolanthus spp.


purple petals: e.g., Anthocleista spp., Chelonanthus spp., Exacum spp., Gentianella spp., Halenia spp.


blue petals: e.g., Exacum spp., Gentiana spp.


black petals: Lisianthius nigrescens


green petals: e.g., Chelonanthus spp., Macrocarpaea spp., Potalia spp.

petals with nectar guides (stripes inside corolla mouth and/or on lobes): Symbolanthus spp.

Corolla with darker lobe apices: some Helieae

corolla with lighter-colored 'eye' in middle of flower: Eustoma, Sabatia


corolla persistent in fruit (does not fall off when fruits develop): many Gentianeae and Chironieae


Glands in the flower (see also Flower anatomy):


colleters (small, finger-shaped glands on inside of sepals): common in many gentians and other families of the Gentianales


colleters absent from calyx: e.g., Bisgoeppertia, Coutoubea, Cracosna, Eustoma


glandular ridge on back of sepals: common in Helieae

nectaries on inside of corolla tube or on lobes: Frasera spp., Gentianella spp., Swertia spp., 


nectary disk at base of ovary: many in tribes Potalieae and Helieae, a few in subtribe Gentianinae, e.g., Gentianothamnus, Tripterospermum


glands at apex of anther: Sebaea spp.


glands at base of anther: Sebaea spp.


Stamens (androecium, filaments, anthers; see also Flower anatomy):


stamens fewer than corolla lobes: Canscora spp., Hoppea, Schinziella


stamens alternating with corolla lobes: all gentians

stamens inserted in the corolla tube: most gentians


stamens inserted in the corolla lobe sinuses: e.g., Aripuana, Djaloniella, Faroa, Geniostemon, Sabatia, Swertia spp.


actinomorphic stamens (symmetric): most gentians


zygomorphic stamens (assymmetric) : e.g., Calolisianthus, Chelonanthus, Cotylanthera, Exacum spp., Orphium, and Symbolanthus


anisomorphic stamens (stamens of different shapes and sizes): Canscora, Hoppea, Schinziella


corona at the base of stamens (ring of tissue): Symbolanthus only


appendages at base of stamens (flaps, hoods, wings): common in subtribe Faroinae and Coutoubea


flattened filaments: many in tribe Saccifolieae


curved filaments: Gentiana sect. Stenogyne and Tripterospermum


winged filaments: Gentiana spp.


apically recurved filaments (filament strongly turned close to the anther): many in tribe Helieae


fused (partially or completely) filaments: Anthocleista, Potalia


fused (connate) anthers: Gentiana spp., Sebaea spp., Tachiadenus spp. [Duncan & Brown, 1954]


long, linear anthers: e.g., Anthocleista, Deianira, Fagraea spp., Potalia, and many in tribe Helieae


recurved (bent) anthers: many in tribe Helieae, e.g., ChelonanthusSymbolanthus

spirally twisted/coiled anthers: many in subtribe Chironiinae, e.g., Centaurium, Chironia, Orphium, Sabatia, Canscora


twisted backwards anthers: Sebaea spp.


longitudinally dehiscent anthers  (with slits): most gentians

sagittate anthers (V-shaped, split at base): many gentians [photo shows anther upside down]

poricidal anthers (pores at apex): Cotylanthera (1 pore), Exacum spp. (2 pores)


introrse anthers (open toward the middle of flower, on the inside of the anther): most gentians


latrorse anthers (open toward the sides of the anthers): Voyriella spp., Saccifolium


anthers with apical appendages (with extra tissue on the tip of the anther): many in tribes Exaceae, Helieae, and Saccifolieae


anthers with basal appendages: some in tribe Exaceae


coriaceous anthers (leathery, thick anthers): Exacum, Gentianothamnus


Gynoecium (pistil, ovary, style, stigma; see also Flower anatomy and Fruits, below) [Gopal Krishna & Puri, 1962]:


bicarpellate gynoecium (formed from 2 fused carpels): all gentians


syncarpous gynoecium: all gentians


stipitate gynoecium (on gynophore): many in tribe Gentianeae


sessile gynoecium: most gentians


style long, filiform, distinct: many in tribes Exaceae, Helieae, Potalieae


style twisted when dry: many Helieae


style zygomorphic: many in tribe Exaceae and Helieae


style short or absent: many in tribe Gentianeae


decurrent stigma along carpel sutures: Bartonia, Lomatogonium spp.


with additional lower stigma: Sebaea spp. [Marloth, 1909]


strongly bilamellate (bilobed) stigma: many Helieae, Fagraea spp., Centaurium, Eustoma

capitate stigma: common, e.g., Lisianthius, Potalia


simple stigma: common in tribe Exaceae


peltate stigma: Voyria spp.

long, coiling stigmatic lobes: Sabatia


Fruits (see also Flower anatomy and Gynoecium, above):

capsules, dry and thin: most gentians


capsules, leathery: Symbolanthus


capsules, woody: Chorisepalum, Tachia

berries: Anthocleista, Chironia baccifera, Fagraea, Potalia, Tripterospermum spp.

(many different colors)


apical, septicidal dehiscence (opens from top along sutures): most gentians with capsules


apical dehiscence, with coriaceous lid: Exacum spp.

medial dehiscence (opens in the middle): some Helieae, Voyria spp.


capsule splits into 4 valves: Macrocarpaea spp., Chorisepalum


indehiscent fruits (never opens): Symbolanthus spp.?, Voyria spp.?, and the genera with berries


parietal placentation (placenta attached to fruit wall): many gentians (this character is very plastic and both parietal and axile placentation can be found within the same gynoecium/fruit in some species)


axile placentation (placenta attached to fruit center), at least for 1/2 of the length of the fruit: many in tribe Exaceae, some in Helieae


intruding placentas (placenta large and intruding far into the fruit from the walls and/or center): common in many gentians, especially in tribe Helieae, e.g., Anthocleista, Centaurium, Fagraea, Gentianothamnus, Tachiadenus


seeds distributed over entire inner wall of fruit: many in subtribe Swertiinae



Seeds (see also Embryology; [Bouman et al., 2002; Grothe & Maas, 1984]): 


numerous seeds: most gentians


round or oblong seeds: Tachia spp., Tachiadenus spp., Voyria spp.


flattened seeds: many in tribe Gentianeae, in subtribe Potaliinae, Chorisepalum, Macrocarpaea spp.


cup-shaped seeds: Exacum spp., Voyria spp.


winged seeds: some in tribe Gentianeae, Chorisepalum, Macrocarpaea spp.


angular seeds: common in tribes Exaceae and Helieae


filiform seeds: Voyria spp.


dust seeds (very small): Voyria


aril: absent in all gentians


aborted seeds, filiform: Voyria spp.


spp. = some species, this indicates that some but not all investigated species in the genus has this character

e.g.= for example


Gentian Research Network, 2002-2011.
For corrections and additions, contact Lena Struwe at