218 



THE JOURNAL OF BOTANY 



Type Characters. 

 Plant 3-4 mm. broad. 



Leaves broader than long, up to 

 3 mm. wide at base. 



One to three small teeth fre- 

 quently occur on the antical 

 margin near insertion. 



Leaf-cells 30 /x diam. near mar- 

 gin ; 30 X 45 ft near middle 

 of leaf. 



Amphigastria very distinct and 

 large, divided to the base in 

 lanceolate ciliated segments. 



Male bracts not gibbous (nicht 

 bauchig geholt). 



Norfolk Plant. 



Some plants reach 4 mm., but 

 3 mm. is the more general 

 maximum width. Slender 

 growths of 2 mm. width are 

 common. 



Breadth about equals length ; 

 1-5 to 2 mm. is an average 

 length and breadth. 



Antical margin near insertion 

 without teeth. 



At apex the cells average 23 x 

 37 //., increasing in size to- 

 wards middle near insertion 

 to 50 X 100 //. 



Amphigastria small and ob- 

 scured by the radicles, though 

 numerous and easily found 

 when searched for ; lanceo- 

 late, toothed, and ciliate at 

 base, and here generally about 

 five cells wide. 



Male bracts distinctly gibbous, 

 insertion transverse, forming 

 well-defined amentulae or 

 Ahren. 



Bearing in mind the stress laid by authors on the large deeply 

 cut amphigastria as a character of diagnostic value, I have had 

 some difficulty in admitting that the Norfolk plant with these 

 organs so small belongs here ; the perianth also offers a difficulty, 

 being conspicuously contracted and beaked at the mouth. 



The habitat is the marshy bottom of a small valley in a chalky 

 Boulder Clay area at 80 ft. O.D. A considerable amount of calcium 

 carbonate is precipitated on the marsh floor from water which 

 drains through the valley, and the submerged vegetation shows a 

 white incrustation when dried. Although no other members of 

 the Leiocolea section have been detected in the county, a large 

 quantity of our plant occurs in this station, forming dense spongy 

 tufts over a limited area, where it is associated with such hygro- 

 phytes as Drosera, Pinguicula, Parnassia, Jimcus, Fissidens adi- 

 antoides, Hypnum stellatum, H. molluscum, &c. The capsule is 

 normally terminal, and takes two seasons to mature. When 

 fertilization has been effected, elongation of the stem usually 

 ceases until the spores are matured, although an innovation 

 sometimes arises from below a fertile perianth. In a large 

 number of cases the perianths are barren, and new growth pro- 

 ceeds by innovation, stems frequently showing three annual seg- 

 ments, each terminated by a small barren perianth. It follows 

 that the maturing capsules are overtopped by the new growth of 



