OZb THREE NEW LASTREAS FROM ASSAM. 



The most nearly-allied form to the above is my newly-proposed 

 species P. crassif alius, which has already been sufficiently discussed. 



Then as true fluitans-i orms, i. e., as probable hybrids with 

 nutans as one parent, I would place certain continental forms which 

 present a strong resemblance to deep-water states of P. polygoni- 

 /alius. I can give no detailed account of these in the present place, 

 as this note is already far too long, but I will remark that P. varii- 

 f olius Thore may possibly come under this division of the group. 

 If continental botanists would carefully examine the waters where 

 pultons-forms grow I think they would soon be able to detect the 

 origin of any supposed hybrids between natans and polygonifolim. 

 Herbarium specimens may serve to suggest such an origin, but the 

 question can only be solved by careful study of the living plants 

 and the conditions under which they grow. 



It is with diffidence that I venture to suggest that further 

 evidence is required before the Neckar plant can be safely admitted 

 to be a> jiuitans- form at all; judging from the dried specimens of 

 fruits and foliage I have seen of " fruiting fluitam," I think it is 

 probable that we have in these plants one or more good species 

 whose true position would be between natans and paly gonij 'alius, and 

 which probably are not hybrids at all. 



Explanation of Plate. — 1. Upper leaves and flowering spike. 2. Lower 

 leaves ; a, pkyllode. 3. Detached stipule bearing a leaf. 



THREE NEW LASTREAS FROM ASSAM. 



By C. W. Hope. 



Nephrodmm (Lastrea) assamense, n. sp. — Caudex erect ; 

 stipes closely tufted, 8-15 in. long, densely clothed at base with 

 linear acuminate blackish or brown scales, and furnished above, as 

 are the rachises, with few or many broad-based long narrow hair- 

 pointed dark brown scales ; fronds lanceolate or subdeltoid, 9-15 in. 

 long, 5-7 in. broad, bipinnatifid or bipinnate towards base of pinna, 

 towards apex suddenly diminishing in width, lowest pair of pinna? 

 sometimes nearly as long as next pair, major pinna? distant 4-6 

 pairs ; pinna; patent or much inclined upwards, lanceolate, acumi- 

 nate, sometimes broadest at base, but there sometimes much 

 narrowed, lowest hardly ever at all unequal-sided, and hardly more 

 compound than others, pinnatifid to a winged rachis into oblong 

 subspatulate segments i-li in. long by ^-f in. wide, somewhat cut 

 away on upper side and decurrent on rachis on lower side, bluntly 

 rounded and sharply toothed at point, rarely slightly pinnatifid at 

 base in largest specimens; segments subentire, with teeth on both sides 

 or distinctly lobed, one lobe to each group of veins with a sharp 

 sometimes double tooth ; texture herbaceous, both surfaces glabrous ; 

 veins, except costa, rarely visible on upper side, but all very distinct 

 against the light, forked or pinnate in the lobes, bipinnate in lowest 

 lobes, all terminating within the margin, fertile veinlets often much 



