Herbs annual or biennial [perennial], chlorophyllous, glabrous. Leaves cauline, opposite [whorled], sometimes also basal. Inflorescences cymes or solitary flowers; pedicels mostly shorter than surrounding internodes. Flowers 4- or 5-merous; calyx with tube cylindric to narrowly campanulate or sometimes very short, sometimes with 1 or 2 sepals distinct to base or nearly so, or rarely cleft on 1 side and spathiform (G. wislizeni); corolla blue, blue-violet, rose-violet, pink, pale yellow, or white, [red, bright yellow, green, bicolored], tubular, funnelform, campanulate, or nearly salverform [nearly rotate], adaxially with or without a fringe of separate trichomes or a deeply fringed scale near the base of each lobe, lobes shorter than tube or ± as long (G. tortuosa) [longer than tube], margins entire or nearly so, without plicae between lobes, spurs absent; stamens inserted near or below [above] middle of corolla tube; anthers distinct; ovary sessile, subsessile, or short-stipitate; style persistent, erect, short or indistinct; stigmas 2; nectaries 1 [rarely 2] per petal, on corolla tube near base. Capsules compressed-cylindric to compressed-ovoid (G. aurea and G. tortuosa). x = 9, 12.

Distribution

nearly worldwide except in Africa, temperate to arctic and alpine regions.

Discussion

Species ca. 250 (10 in the flora).

Gentianella in the flora area includes some species having vascularized fringes of trichomes or deeply fringed scales near the throat of the corolla and other species lacking any such fringes, vascularized or not. Molecular studies indicate that Gentianella circumscribed to include both of these groups (but excluding Asiatic species with paired nectaries) is monophyletic and that each of the two groups as traditionally defined is very largely monophyletic. Gentianella microcalyx is an exception, evidently being more closely related to the species with fringed corollas although it lacks fringes itself (K. B. von Hagen and J. W. Kadereit 2001). These two groups have occasionally been distinguished at generic rank, species 1 through 7 being retained in Gentianella and species 8 through 10 being placed in Aloitis. When both groups are retained in Gentianella, they have sometimes been designated sect. Gentianella and sect. Arctophila (Grisebach) Holub, respectively.

The corolla fringes normally present in species 1 through 6 may be reduced or absent on small flowers on the proximal branches or on flowers produced late in the season, or on all flowers of the smallest plants.

Selected References

None.

Lower Taxa

Gentianella amarella, Gentianella aurea, Gentianella auriculata, Gentianella heterosepala, Gentianella microcalyx, Gentianella propinqua, Gentianella quinquefolia, Gentianella tortuosa, Gentianella wislizeni, Gentianella wrightii

Key

1	Corollas without adaxial fringes of trichomes or scales.	> 2
2	Calyx tubes deeply cleft, spathaceous; lobes minute, linear, 0.5–1.5 mm.	Gentianella wislizeni
2	All sepals united proximally to ± the same level, tube not deeply cleft or spathaceous; lobes usually 2–20 mm (occasionally some smaller only in G. microcalyx and G. quinquefolia subsp. quinquefolia).	> 3
3	Stems usually branched only above base if at all; calyx lobes subequal or ± irregular but not distinctly dimorphic.	> 4
4	Corolla lobe apices obtuse to acute but not attenuate; calyces 2–3(–5) mm; corollas 6–13 mm; Arizona.	Gentianella microcalyx
4	Corolla lobe apices short-attenuate; calyces 2–15 mm; corollas 10–25 mm; c, e North America.	Gentianella quinquefolia
3	Stems (except of smallest plants) branched from near base; 2 outer calyx lobes distinctly larger than inner.	> 5
5	Flowers (4- or)5-merous; outer calyx lobes oblong to narrowly obovate, larger than inner but not foliaceous; inflorescences proximally ± enveloped by sub­tending leaves; Greenland.	Gentianella aurea
5	Flowers 4-merous; outer calyx lobes elliptic to ovate-oblong, often ± foliaceous; inflorescences not proximally enveloped by subtending leaves; widely distrib­uted but not in Greenland.	Gentianella propinqua
1	Corollas of all or all but smallest flowers with fringes of trichomes or deeply fringed scales adaxially near base of lobes.	> 6
6	Calyx tubes deeply cleft, spathaceous; all calyx lobes becoming distinct at the summit of the tube, minute, linear, 0.5–1.5 mm.	Gentianella wislizeni
6	Calyx tubes not spathaceous, composed of either all sepals united proximally and all lobes becoming distinct from each other at ± the same level, or with 1 or 2 lobes distinct nearly to the base but with the other sepals united to a higher level and becoming distinct at the summit of the tube; lobes diverse in shape, 2–20 mm.	> 7
7	Calyces with 1 or 2 lobes distinct nearly to base of calyx, these ovate, foliaceous, proximally enveloping the other lobes; fringes on adaxial corolla surface basally connate, forming deeply cleft scales.	Gentianella heterosepala
7	Calyces with all lobes proximally connate, diverging distinctly above base of calyx, ± equal or unequal but none foliaceous; fringes on adaxial corolla surface consisting either of trichomes separate to base or of fringed scales.	> 8
8	Plants 2–10(–16) cm; corolla lobes ± as long as tube.	Gentianella tortuosa
8	Plants 2–50(–80) cm; corolla lobes distinctly shorter than tube.	> 9
9	Plants 2–25(–30) cm; calyx lobes, ovate-triangular to suborbiculate, shorter than tube; fringes on adaxial corolla surface basally connate, form­ing a deeply cleft scale at the base of each lobe; Alaskan islands.	Gentianella auriculata
9	Plants (2–)4–50(–80) cm; calyx lobes linear or linear-oblong to lanceolate or nar­rowly elliptic, ± as long as or longer than tube; fringes on adaxial corolla surface consisting of trichomes separate to base; widely distributed in the flora area, including (G. amarella) Alaskan islands.	> 10
10	Corolla lobes 3–5.5 mm; corollas blue to purplish pink, pale yellow, or white, 7–21 mm.	Gentianella amarella
10	Corolla lobes (5–)7–10 mm; corollas white or pale yellow, (15–)20–30 mm.	Gentianella wrightii