MONOCOTYLEDONS. AROIDE^. Spargamum. 1 9 1 



SECT. II. PisTiACEjE. Rich. In Huml. Nov. Gen. Spadix 2- 

 Jloivered, in a cu&dlate spatfia. Flowers with anthers and 

 pistils separate. Capsule or Utricidus. Floating plants. 

 2. LEMNA. 



Male and female flowers collateral. Stamens'!. Utricidus 1 5- 

 see<led a . 



1. L. trisulca, fronds thin elliptico-lanceolate caudate at one ex- 

 tremity at the other serrate, roots solitary, p. 10. Stagnant 

 waters. 



2. L. minor, fronds nearly ovate compressed, roots solitary. p.\\. 

 Stag?iant wafers. 



3. L.polurrhiza, fronds obovato-rotundate compressed, roots nu- 

 merous clustered, p. 11. 'Stagnant waters. 



4. L. gilla, fronds obovate nearly plane above hemispherical 

 beneath, roots solitary, p. 11. Stagnant waters, rare. 



SECT. III. TYPHINJE. Juss. Flowers monoecious, lut surrounded 



ly a perianth.. S tarn. 3. Ouary l-seeded; ovule pendulous. 



Fruit an achenium. 



3. SPARGANIUM. 

 Flowers collected into spheerical, dense heads, which are stami- 



niferous or pi still iferous. Barren Fl. Perianth of 3 leaves. 



Fertile FL Perianth of 3 leaves. Drupe dry, with 1 seed. 



1. S. ramosum, leaves triangular at the base their sides concave, 

 common flower-stalk branched, stigma linear, p. 260. Staff- 

 nant ivalers. 



2. S. simplex, leaves triangular at the base their sides plane, 

 common flovverstalk simple, stigma linear, p. 260. Still wa- 

 ters. 



3. S. natans, leaves floating plane, common flowerstalk simple, 

 stigma ovate very short, head of sterile flowers mostly solita- 

 ry, p. 260. Ditches. 



a The first, and, we believe, only botanist who has ventured to place 

 Lemna and Pist'ta next each other is Linnaeus ; who could have had a very 

 imperfect knowledge of the latter, and a far from complete acquaintance 

 with the former. Notwithstanding the different manner in which Pist'ia and 

 Lcmna have been described, it is in these descriptions only that they really 

 disagree, and notin natural affinity. Suppose what is called perianth &tp. 10, 

 Part I. to be a spatha ; and we have a spadix reduced to a point bearing two 

 naked fioiuers, of which the superior is male and diandrous, the inferior fe- 

 male. Let this account be compared with M. Kunth's character of Ptstla 

 in the Nova Genera et Species Plantarum of Baron Humboldt, and it will be 

 found to be absolutely the same, except in the single particular of capsule. 

 Nor can we perceive any other than generic differences between the two 

 genera, as far as it is possible to judge of Pistla from Roxburgh's account of 

 it. We ought to add, that Mr, Brown first remarked to us that Lemna wa 

 a reduced Aroidea. 



