GENTIAN FAMILY 351 



Style slender almost filiform, usually dehiscent from the fruiting capsule. 



Calyx 4-toothed and 4-angled; corolla short-salverform, 4-lobed; anthers cordate-ovate, not coiled or 



recurved after dehiscence. 1. Microcala. 



Calyx 5- (rarely 4-) parted almost to the base; anthers oblong or linear. 



Corolla salverform, pink or rarely white; anther spirally twisted after anthesis. 



2. Centaurium. 



Corolla campanulate-funnelform, bluish or white; anthers not spirally coiled after anthesis. 



3. Eustoma. 



Style short, subulate and persistent, or none. 



Corolla campanulate to funnelform, without glands on the inner surface of the lobes. 



4. Gentiana. 



Corolla rotate, the tube very short, the lobes bearing a large single or double gland on the inner surface. 



5. Swertia. 



1. MICROCAlA Hoffm. & Link, Fl. Port. 1: 359. 1806. 



Small annual herbs, with simple or branched, filiform stems, the branches or peduncles 

 bearing a solitary terminal flower. Leaves opposite, entire, sessile. Calyx 4-angled and 

 4-toothed. Corolla salverform, 4-lobed, the lobes convolute in the bud. Stamens 4, 

 attached to the throat of the corolla; anthers cordate-ovate. Style filiform, deciduous; 

 stigma 2-lobed, the lobes flabelliform, at first connivent. Capsule ovoid, usually covered 

 by the withering-persistent corolla. Seeds minute, numerous, minutely reticulately pitted. 

 [Name from two Greek words meaning small and beautiful.] 



A genus of 2 species, the second one, M. filiformis (L.) Hoffm. & Link which is the type species, inhabits the 

 Mediterranean region and central Europe. 



1. Microcala quadrangularis (Lam.) Griseb. American Microcala. Fig. 3787. 



Gentiana quadrangularis Lam. Encyl. 2: 645. 1790. 

 Exacum quadrangularis Willd. Sp. PI. 1: 636. 1797. 

 Microcala quadrangularis Griseb. in A. D.C. Prod. 9: 63. 1845. 



Glabrous annual, the stems simple or few-branched, erect, 2-8 cm. high. Basal leaves 

 usually 4 or 6, approximate on account of the very short internodes, those above the base in 

 2 or 3 rather distant pairs, oblong-linear to oval, 4-8 mm. long; calyx 3-6 mm. lonfi, 4-ancrled 

 with 4 alternating ribs, the teeth very short, subulate; corolla yellow, short salverform, about 

 6 mm. long, the lobes about 2 mm. long ; capsule ovoid about equaling the calyx. 



Grassy places, mainly Upper Sonoran Zone; Willamette Valley, Oregon, to the Sacramento Valley and 

 Sierra Nevada foothills and the California Coast Ranges to northern Santa Barbara County; also western 

 South America. Type locality: environs of Lima, Peru. April-June. 



2. CENTAURIUM Hill, Brit. Herb. 62. 1756. 



Annual or rarely biennial glabrous herbs, with opposite, sessile or amplexicaul leaves. 

 Flowers spicate or cymose, 4-5-merous, white, pink or yellow. Calyx narrow, cylindric, 

 4— 5-lobed or -divided, the lobes linear or linear-lanceolate, frequently keeled and scarious- 

 margined. Corolla salverform, 4-5-lobed, the lobes contorted, convolute in the bud, 

 usually much shorter than the tube. Stamens 4 or 5, inserted on the corolla-tube and 

 alternating with the lobes. Ovary 1-celled, the parietal placentae sometimes intruded ; 

 style very slender, deciduous; stigma 2-lobed. Capsule oblong-ovoid to fusiform, 2-valved. 

 Seeds oblong to spherical, minute, reticulated. [From the ancient name (Latin centaur- 

 eum, Greek kentaurion) of two plants Chlora perfoliata and Centaurium umhellatum, 

 the medicinal properties of which were supposed to have been discovered by the centaur 

 Chiron.] 



A genus of about 30 species, chiefly in the northern hemisphere. Type species, Gentiana Centaurium L. 



Flowers in rather crowded umbellate cymes terminating the branches, sessile or subsessile, the pedicels when 

 present not over 1 mm. long, each flower subtended by a bract bearing a rudimentary floret in its axil. 

 Basal leaves tufted. 1. C. umbellatum. 



Basal leaves not tufted. 2. C. floribundum. 



Flowers pedicellate or if sessile without subtending rudimentary florets. 



Anthers oblong, l.S-2.5 mm. long; corolla-lobes less than half the length of the tube. 

 Pedicels short, the longest not over 12 mm. long. 



Pedicels not over 0.5 mm. long, the ultimate cymules 2-3-flowered; anthers not spirally coiled 

 after anthesis, not sagittate, one cell longer than the other; stigma-lobes narrower than long. 



3. C. Muhlenbergii. 



Pedicels 1-12 mm. long; ultimate cymules loosely flowered; anthers spirally coiled after anthesis, 

 sagittate at base and the cells of equal length; stigma-lobes broader than long. 



Corolla-lobes narrowly oblong-lanceolate, 3.5 mm. long, scarcely 1.5 mm. broad. 



4. C. cnrvistaminium. 



Corolla-lobes ovate, 5-5.5 mm. long, 2.5-3 mm. broad. 5. C. Davyi. 



Pedicels, at least some of them, over 20 mm. long; corolla-lobes 3-4 mm. long, oblong. 



6. C. e.taltatum. 

 Anthers linear, 3.5 mm. long; corolla-lobes over half the length of the tube. 



Stigma-lobes always appressed against each other, 0.5 mm. high, very narrow, the style not divided 



below them. 7. C. trichanthum. 



Stigma-lobes divaricately spreading, 1-1.5 mm. high and nearly as broad, the style cleft for a short 

 distance beneath them. 8. C. venustum. 



