SPECIES AND VARIETIES. 329 



the stem below, cylindrical upwards, hollow, but divided inside 

 by cross partitions of pith, which give them the appearance of 

 being jointed; flowers in little clusters, arranged in a com- 

 pound terminal panicle ; perianth-segments all pointed, or the 

 inner ones obtuse; capsule more or less pointed. Boggy 

 places. Fl. June to August. 



J. obtusiflorus differs only from the common larger erect 

 form of J. articulatus in having all the segments of the pe- 

 rianth obtuse or nearly so, and about as long as the very 

 pointed capsule. Marshes, rather rare. 



ft Leaves grooved above, not jointed internally. 



J. compressus : sterns 1-1 i foot high, erect, rather slender, 

 with a few nearly radical leaves shorter than the stem, and 

 12 higher up, all narrow and grooved ; flowers scarcely clus- 

 tered, in a loose terminal panicle, shining brown ; perianth- 

 segments obtuse ; capsule roundly-ovate, about as long. 

 Wet marshy places, especially near the sea. Fl. June to 

 August. 



J. bufonius : annual ; stems numerous, forming dense tufts, 

 18 inches high, branching and flowering almost from the 

 base; leaves chiefly radical, short, slender, angular, grooved; 

 flowers solitary along the branches, the lower bracts leaf-like ; 

 perianth-segments narrow, pointed, pale-green, with scarious 

 edges; capsule oblong, shorter. Wet places. FJ. July, Au- 

 gust. 



*** Leaves all radical, numerous. 



J. squarrosus : leaves all radical or nearly so, short, nume- 

 rous, very narrow, grooved, stiff, spreading ; flower-stem nearly 

 a foot high, rigid, with a terminal panicle ; flowers usually 

 distinct; perianth-segments rather broad, glossy brown, with 

 broad scarious edges. Moors and heaths. Fl. June, July. 



