Oentiana.] L. GENTIANACE^l. 303 



and autumn. The flowers (including the limb) vary with us from 6 to 

 9 lines in length, more rarely attaining an inch, whilst in some Conti- 

 nental specimens they are sometimes yet longer. 



[0, gei-manica, Willd., is a stout, large-flowered variety with more un- 

 equal calyx lobes and shorter corolla-tube ; it is confined to England. 

 Another variety, G. uliginosa, Willd. , has 4-merous rlowers. These seem 

 to unite G. Amarella with campestris.] 



5. G. campestris, Linn. (fig. 681). Field G. An erect annual, much 

 resembling at first ight G. Amarella, but usually rather stouter, more 

 branched, and with more crowded leaves and flowers, though seldom 

 above 6 inches high ; and it is easily known by the parts of the flower 

 being in fours, not in fives, and by 2 of the lobes of the calyx being 

 broadly ovate, overlapping the 2 other narrow ones. The blue fringe 

 of the mouth of the corolla is very conspicuous. 



In open pastures, and commons, chiefly in limestone districts, in 

 central and northern Europe, but not recorded from the Caucasus or 

 eastward of the Ural, More frequent in Britain than the last species. 

 Fl. autumn. 



IV. CHLOEA. CHLORA. 



Glaucous annuals, with yellow flowers. Calyx deeply divided as in 

 Erythrcea, but into 8 lobes. Corolla-tube very short ; the limb spread- 

 ing, 8-lobed. Stamens 8. Style persisting on the capsule as in Gentian. 



Besides the British species, the genus includes a few European ones. 



1. C. perfoliata, Linn. (fig. 682). Ydloivwort. An erect, rather 

 stiff annual, 2 or 3 inches to a foot high, of a pale glaucous green. 

 Radical leaves in a spreading tuft, those of the stem in distant pairs, 

 broadly connected together at the base, so that the stem appears to 

 pass through them, whence the specific name. Flowers of a bright 

 yellow, in rather loose terminal cymes ; the corolla nearly rotate. 

 JBlackstonia perfoliata^ Huds. 



In dry pastures, and waste places, generally confined to limestone 

 districts, in western, central, and southern Europe to the Caucasus. In 

 Britain, limited to England, where it is local, and Ireland. Fl. summer. 



V. MENYANTHES. BUCKBEAN. 



A single species, distinguished as a genus from Limnanthemum by its 

 compound leaves and the capsule opening in 2 valves. 



1. M. trifoliata, Linn. (fig. 683). JSuckbcan, Marsh Trefoil. An 

 aquatic herb, with creeping rootstock and densely-matted roots. Stem 

 short, creeping or floating, with a dense tuft of leaves, consisting each 

 of a long stalk, sheathing at the base, and 3 obovate or oblong leaflets, 

 1 to 1 ^ inches long. Flowers white, tinged externally with red, in an 

 oblong raceme, on a peduncle of 6 inches to a foot, proceeding from 

 the base of the tuft of leaves. Calyx short, with rather broad green 

 lobes. Corolla campanulate, deeply 5-lobed, and elegantly fringed on 

 the inside with white filaments. 



In wet bogs, and shallow ponds, in Europe, Russian and central Asia, 

 and North America, extending into the Arctic regions. Diffused all 

 over Britain. Fl. summer, rather early. 



