354 A CEYLON ISOETES. 



where known in Ceylon, is abundant on the bare rocks along with 

 many other shrubs, such as Frotium caudatum, Croton Klotzchianum, 

 Randia duinetoriim, and abundance of the endemic Favetta Gleniei. 

 A great stiff grass with serrate-edged leaves, Garnotia stricta, is very 

 conspicuous. But it is in the crevices of the rocks, after the rains, 

 that a very rich flora of small herbaceous species flourishes, such 

 as Zornia, Stylosanthes, Acantlionotus echinatus, Bonnaya brachiata, 

 Dopatriiim nudicaule, Cleome mono])hyUa, Fortulaca sufnUicosa (of 

 Thwaites, ' Enum. PI. Zeyl.,' not of ' Fl. Brit. India '), Ludwigia 

 jiarrifiora, Habtmaria viridijiora, Favonia odorata ^'lih. white flowers, 

 several minute species of Kriocaulon and Fimbristylis, &c. I 

 gathered sparingly in such spots also a very small Ophioglossiini, 

 ^ to 1| in. in height, which is, I presume, 0. f/ramineiim, Willd., 

 originally collected by Kouig at Madras, and now reduced to 

 O. ludtanicuin in the ' Synopsis Filicum.' The curious little grass 

 Oropetium Thornmim, also first found at Madras; an endemic fern, 

 Cheilanthe.s Thwaitesii ; and Selaymella nipestris, are all common. 



In this part of Ceylon, as indeed in all parts except the well- 

 known south-western districts and the mountain region, — which 

 being the portions of the island most familiar to Europeans are 

 often quoted as if characteristic of the whole, — there is a long dry 

 season broken by a short period of heavy rain. At the time I paid 

 my visit to Dambulla in December this latter was scarcely over. 

 In the rock hollows the water stands for some time, and it was in 

 some pools of this sort near the base of the hill that the subject 

 of this note was discovered. 



This Isoetes, though found completely submerged beneath the 

 surface of the water, is probably capable of bearing a more or less 

 terrestrial life at other times of the year. Its leaves are abun- 

 dantly supplied with stomata. 



The following is a brief description of the plant : — 

 PJiizome strongly 3-lobed, truncate or hollowed out beneath, 

 about ^ inch in diameter, black externally. Leaves about 

 16-36 in number, erect, 6-9 in. long, stiff and firm, bluntly 

 pointed, quite triangular above but with the keel rounded 

 below, flat on upper surface, bordered for about this lower 

 two inches by a perfectly transparent hyaline wing which 

 gradually dilates downwards, attaining fully J in. wide above 

 the sporange, and then rather suddenly dilates to support the 

 sporange measuring ^ in. in width at its insertion. Ligule 

 extremely delicate, when perfect about ^ length of sporange, 

 triangular, acute, in old leaves usually truncate from decay or 

 frayed from injury. Macrospores milk-white, strongly ribbed, 

 when dry chalky and the sides covered with blunt promi- 

 nences. I could not discover any microspores. 

 There are two species of Isoetes described from Peninsular India, 

 one from Madras, the other from Saharunpore in the north-west 

 Provinces. The first is /. coromandelina, Linn, fil., the received 1. 

 capsulari.s, Griff. It is difficult to discover valid ground for their 

 separation, but the late A. Braun — who paid great attention to the 

 genus — has distinguished them by their ligulc", and iuimcd the 



