89 



generally abundant in those places where it occurs. The whole plant 

 is exceedingly rigid and wiry, varying in height from two to four or 

 five inches at most. Stems usually decumbent at the lower part, 

 rather thick compared with their length, smooth, striated. Leaves 

 linear, rigid, flat, or only becoming convolute when dry. Panicle 

 dense, often resembling a spike, or otherwise with the spikelets arranged 

 as a raceme. Spikelets mostly solitary, on short footstalks, ovate, 

 oblong, or occasionally linear; six- to twelve-flowered; alternately 

 disposed upon the rachis, but inclining to one side. Glumes nearly equal, 

 the apex of the upper one reaching to the base of the fourth flower, a 

 feature remarkably constant if of any real value. Lower palea more or 

 less distinctly five-veined ; the marginal veins broad and well marked, 

 and often with a white line down the middle ; the dorsal one extended 

 beyond the obtuse extremity of the palea as a short point or mucro. 



Annual. Flowers in June and July. 



Although the generic allotment of this little grass has been long 

 undetermined, as the above synonynjs sufficiently indicate, while the 

 affinities of Sclerochloa rigida have seldom been questioned, they cor- 

 respond so closely in structure as to render their specific separation 

 even problematical, some states of the latter species being all but un- 

 distinguishable from the present. Modern writers have not much 

 relieved the difficulty by pointing out the difference in the comparative 

 length of the upper glume, reaching in one case to the base of the third 

 flower of the spikelet, in the other to that of the fourth. A dissimi- 

 larity in habit or general aspect, familiar to my eye from boyhood, 

 renders me averse to the decision that they are mere local varieties, 

 and raised, from seed, in the inland garden, Sclerochloa loliacea retained 

 its usual character, or only differed in being rather less glaucous than 

 its sea-side progenitors : still, in the absence of more marked structural 

 characters, its individuality is doubtful. Withering, who regarded it 

 as a species of Triticum, in opposition to Hudson, who classed it as a 

 Poa, remarks " the serpentine spike-stalk (rachis), which from the spike- 

 lets facing one way becomes visible behind through its whole length, 

 has a strong wood-like mid-rib, edged with a thinner and greener 

 border, the same as in the Poa rigida." Apart from the natural mari- 

 time habitats of the present, its geographical distribution nearly accords 

 with that of the last species. 



Genus 30. GLYCERIA. Sweet Grass. 



Gen. Char. Inflorescence, more or less branched and loosely pani- 

 culate. Spikelets stalked, four- to many-flowered. Glumes two, 

 single-veined, unequal, obtuse, membranaceous, small, shorter 

 than the palese of the lowermost flower. Palese two ; the lower 

 one seven-veined, with scarious margins, subcylindrical ; the 

 upper one shorter, bifid at the apex, with two marginal veins. 



Nearly allied to Poa, of which genus it is by many botanists only 

 regarded as a section, while by others it is ignored altogether. The 



