L. Cockayne 
i 14 
(c) Apium filiforme x prostratum. 
These two herbs constantly occur together as members of salt- 
meadow together with intermediates of many forms. In the Manual , 
p. 205, because of such intermediates the species are united, never¬ 
theless filiforme is upheld as a variety. Inland A . filiforme (A . pros¬ 
tratum being absent) shows no polymorphy other than environmental. 
( d ) Acaena inermis x microphylla. 
These species frequently occur side by side on stony ground, 
especially in the montane belt. The special distinction between the 
two is the presence and absence of bristles on the flower-heads. In 
the hybrids all degrees in the production of bristles can be seen on 
the same individual. There is also a multiplicity of forms—especially 
colour of leaf—due, doubtless, to crosses between the varieties of 
the two aggregate species. This case would lend itself admirably to 
Mendelian analysis. 
2. Hybrids between species of a more or less similar wide range 
and ecological requirements , but which only meet occasionally. 
This class is the opposite of (1); it includes 13 hybrids. In most 
cases probably slight ecological differences in their requirements 
keep the species apart. 
(a) Celmisia Lyallii x spectabilis (= C. pseudo-Lyallii (Cheesem.) 
Cockayne). Its hybrid origin is suggested in The Vegetation of 
New Zealand , p. 342, 1921. 
This is apparently a case where a more or less invariable hybrid 
is produced, which, if truly invariable, should be looked upon not as 
a hybrid but as a valid species which differed only from species in 
general in that its origin was actually known. The hybrid has not 
been recorded from localities where one of the parents is absent. It 
has the leaf-form of C. Lyallii, but without the characteristic grooves, 
and the texture and tomentum of the leaf is that of C. spectabilis. 
In some places the hybrid is abundant. 
(b) Celmisia coriacea x Lyallii. 
This hybrid, discovered by Mr H. H. Allan on Mount Peel 
(Canterbury), somewhat resembles that just dealt with in its leaf- 
form, but it has the silvery tomentum of C. coriacea. It is apparently 
rare. In some respects it is not unlike C. Petriei Cheesem. 
(1 c) Muehlenbeckia axillaris x ephedroides (= M. muricatella Col.). 
This hybrid has been observed in several localities where, on 
gravelly ground, the two species grow side by side. It preserves the 
