PONTEDERIACE.E, XYRIDACE.E, ERIOCAULONACE^E. 247 



OBDER CVII. PONTEDERIA'CE^. (PICKEREL-WEED F.) 



The most common representatives of this Order with us 

 are 



1. POXTEDE'RIA, L. PlCKEREL-WEED. 



P. COrda'ta, L. A stout plant growing in shallow water, 

 sending up a scape bearing a single large arrow-heart-shaped 

 blunt leaf, and a spike of violet-blue flowers with a spathe-like 

 bract. Perianth 2-lipped, the 3 upper divisions united, the 3 

 lower spreading, the whole revolute-coiled after flowering, 

 the fleshy base enclosing the fruit. Stamens 6, 3 of them 

 exserted on long filaments, the rest short. 



Var. angnstifolia, Torr., has narrow scarcely cordate 



leaves. 



2, SCHOL'LERA, Schreber. WATER STAR-GRASS. 



S. gramin'ea, Willd. (Heteranthera graminea, Vahl., in 

 Macoun's Catalogue.) A grass-like herb, wholly under 

 water, only the small yellowish flowers reaching the surface, 

 the latter single, from spathes. Perianth salver-shaped, 

 regular. Stamens 3, anthers sagittate. 



ORDER CVIII. XYRIDA'CE^. (YELLOW-EYED-GRASS F.) 

 Rush-like herbs, with equitant leaves sheathing the base 

 of a naked scape, terminated by a head of perfect 3-androus 

 flowers, with glumaceous calyx and coloured corolla. Cap- 

 sule 3-valved and 1-celled, containing several or many seeds. 



XYKIS, Gronov. YELLOW-EYED GRASS. 



X. flexuo'Sa, Muhl., vaV. pusill'a, Gray. Scape small 

 and very slender, 2-9 inches high, not bulbous at the base. 

 Flowers in the axils of scale-like bracts densely imbricated 

 in a head. Sepals 3. Petals 3. Fertile stamens 3, with 3 

 alternating sterile filaments bearded at the apex. Peat bogs 

 and wet sandy shores, Atl. Prov. and northward. 



ORDER CIX. ERIOCAULONA'CE^l. (PIPEWORT F.) 

 Represented with us by the genus 



KKHH II LO\, L. PlPEWORT. 



E. septangula're, Withering. A slender plant with a 



