446 PAKNASSIA. [CLASS V. ORDER IV. 



ORDER IV. 



TETRAGYNIA. 4 PISTILS. 



GENUS XCIX. PARNAS'SIA. LINN. Grass of Parnassus. 



GEN. CHAR. Calyx five-parted, spreading. Petals five, veiny, and 

 opposite the base of each is an heart-shaped fleshy scale, fringed 

 with slender bristles, tipped with globular glands. Stic/mas four, 

 sessile. Capsule superior, of one cell, opening at the apex with 

 four valves, each with a linear placenta bearing numerous seeds. 

 Named from Mount Parnassus, though the plant is by no means 

 peculiar to that situation. 



1 . P. palus'tris, Linn. (Fig. 509.) Common Grass of Parnassus. 

 Scales with from nine lo thirteen bristles ; root leaves on footstalks, 

 heart-shaped, the solitary one of the stem amplexicaul. 



English Botany, t. 82. English Flora, vol. ii. p. 114. Hooker, 

 British Flora, vol. i. p. 147. Lindley, Synopsis, p. 67. 



Root of numerous long branched fibres. Stem erect, angular, 

 Striated, twisted, from " one inch" to eight or twelve high, quite smooth, 

 as is the whole plant, with a solitary leaf below the middle, sessile, 

 and embracing it Leaves from the root numerous, on rather long 

 channeled footstalks, heart-shaped, more or less acute at the point, not 

 unfrequently rounded, with a mid-rib and several lateral ones from the 

 base, paler beneath, and more or less profusely scattered over with 

 small oblong glands, of a pinkish colour, sometimes wanting, but best 

 seen in dried specimens, they are also numerous on the footstalks and 

 lower part of the stem. Flower solitary at the top of the stem. Calyx 

 five-partite, the segments ovate, acute, with numerous slender longi- 

 tudinal veins, spreading. Corolla of five broadly ovate obtuse spread- 

 ing concave petals of a beautiful white, with numerous pellucid veins, 

 and sometimes, though rarely, the margin is fringed, the base with a 

 short claw, and opposite to it is a fleshy heart-shaped scale, on a short 

 stalk, having the margin fringed with from nine lo thirteen awl-shaped 

 slender bristles, each tipped with a small round yellow gland. Stamens 

 alternating with them, and about the same length, with awl-shaped 

 filaments and oval anthers, pale cream colour, of two cells, bursting 

 longitudinally. Stigmas four, sessile, obtuse, spreading, crowning the 

 capsule, which is broadly ovate, marked with four longitudinal furrows, 

 nearly superior, of one cell, bursting about half way down from the 

 apex, each with a longitudinal lateral placenta, bearing numerous 

 small brown seeds, curved upwards, with a narrow membranous border 

 all round. 



