92 TEIANDRIA DIGYNIA. [CL. III. 



41. ROTTBO'LLIA. HARD-GRASS. , 

 Common receptacle elongated, jointed, ultimately separating, 

 alternately excavated to receive the flowers, of which there are 

 commonly two in each excavation, one of them only being 

 perfect. Calyx of two parallel lance -shaped valves, opposite 

 to the excavation. Corolla of the perfect flower of two lance- 

 shaped, membranous, nearly equal husks, inflected at the edges. 

 Nectary of two acute scales. Filaments thread-like ; anthers 

 oblong, cleft at both ends. Germen oblong, obtuse. Styles 

 short ; stigmas feathery, spreading. Seed oblong, shut up in 

 the cavity of each joint of the receptacle by the closed husk^, 

 and falling off along with it. Named after Professor Rottboll 

 of Copenhagen. 57. 



1. R. incurvdta. Sea Hard-grass. Spike cylindrical, slender ; 



chaff-scales united below ; corolla awnless. Straws numerous, 



from three to five inches long, spreading, round, smooth, jointed, 

 leafy : leaves short, firm : spike very slender, hardly distinguishable 

 from the straw. Annual : flowers in July and August : grows on 

 the sea-shore : rare. Eng. Sot. vol. xr. pi. 760. Eng. Fl. vol. i. 

 p. 176. 206. 



42. E'LYMUS. LTME-GRASS. 



Common receptacle elongated, alternately excavated and 

 toothed on each side. Spikelets two or more at each tooth. 

 Calyx to each spikelet of two unequal, broadly lance-shaped 

 husks, the outer largest, keeled, and pointed or awned, the 

 inner cleft, inflected at the edges, with a rib on each side. 

 Nectary of two lance-shaped scales. Filaments hair-like, very 

 short ; anthers linear, notched at both ends. Germen turbi- 

 nate. Stigmas feathery, spreading ; seed linear, channelled on 

 the upper side, very hairy at the summit. Name, elymos, of 

 the Greeks. 58. 



1. E. arendrius. Upright Sea Lyme-grass. Spike erect, close ; 

 calyx lance-shaped, as long as the spikelets ; leaves stiif, with a 



thorny point. Root creeping: straws three or four feet high, 



erect, firm, round, striated, leafy : leaves hard and stiff, involute 

 with a thorny point : spike from six to twelve inches long. Peren- 

 nial : flowers in July : grows in sand on the sea-shore, in England, 

 Scotland, and Ireland ; but not common. Eng. Bot. vol. xxiv. 

 pi. 1672. Eng. Fl. vol. i. p. 177. 207. 



2. E. geniculdtus. Pendulous Sea Lyme-grass. Spike bent down- 

 wards, lax ; common receptacle winged ; calyx awl-shaped, longer 



than the spikelets ; leaves stiff, with a thorny point. Root 



fibrous : straws taller but more slender than in the last : spike 

 nearly two feet long. Perennial : flowers in July : grows in 

 marshes near the coast : very rare. Salt-marsh, near Gravesend. 

 Eng. Bot. vol. xxiii. pi. 1586. Eng. Fl. vol. i. p. 178. 208. 



3. E. europce'us. Wood Lyme-grass. Spike erect, close ; spike- 

 lets of about two flowers, rough, awned ; calyx awned, as long as 



the spikelet ; leaves flat, pliant. Root fibrous : straw erect, two 



feet high, round, smooth, leafy : leaves lance-shaped, ribbed, flat, 

 acute, rough : spike two or three inches long, erect, close, green : 

 spikelets three at each notch. Perennial : flowers in June : grows 



