616 



less coriaceous, rather less glaucous, bending upwards (or inwards 

 towards the stem) between base and tip, and with less tendency to 

 become revolute at their margins. The internodes are somewhat lar- 

 ger on the whole ; though this is not a well-marked chai'acter. 



On the contrary, the young plants of Polygonum maritimum never 

 became abruptly bent into the horizontal position. They increased 

 in length, they gradually became procumbent at their base, with as- 

 cending or even almost erect branches. At a later stage they are 

 distinguishable from Polygonum Raii by the harsher texture of their 

 ochreaj, which have numerous, strong, dark russet nerves. The 

 leaves are more ovate or oval, coriaceous, very glaucous, convex on 

 the upper surface, revolute at their margins, from the tip backwards 

 for the half or two-thirds of their length, and diverging from the stem 

 or branch. The seeds are rather smaller ; but it is doubtful whether 

 a botanist could again correctly separate the seeds of the two species 

 if mixed together. 



During our past mild winter, one of the last year's plants of P. ma- 

 ritimum survived in the open ground, and several in flower-pots in a 

 cold frame. These have become quite ligneous at the bases of their 

 stems or branches, and the internodes of this summer's growth are 

 much shorter than was the case with those of first-year plants, during 

 1843, 4, 5, which were made annuals by the severity of our winters. 

 Thus, as might have been anticipated, the length of the internodes 

 proves to be only a fallacious character, changing with age and 

 season. 



So far as my garden- grown plants aflford good distinctive charac- 

 ters — and these correspond well enough with my recollections of the 

 wild plants on the coasts of England and the Azores — the specific 

 or varietic (to coin a termination) characters may be taken as below. 

 Between the prostrate plants of our own shores, and the lavender-like 

 bushes of the Azores, evidently the growth of many years, the first- 

 sight difference is wide enough. Whether this may not arise as much 

 from climate and place, as from distinctness of species, may still ad- 

 mit of question. Compared with each other, the following characters 

 will distinguish these two and Polygonum aviculare : — 



P. maritimum. — Perennial. Stems ascending from a procumbent 

 and ligneous base. Leaves coriaceous, very glaucous, convex 

 above, revolute at the margin, diverging from the stem. 

 Ochreae with numerous, strong, dark nerves. Fruit large, 

 smooth, shining, conspicuously longer than the perianth. 

 P. Raii. — Perennial .'' Stems prostrate. Leaves glaucous, plane. 



