182 Field, Forest, and Wayside Flowers 
to prevent a cylinder of delicate tissue froin col- 
lapsing.”’ 
The same problem has occurred in the organiza- 
tion of some seaweeds, and has been 
solved by Nature in almost the same 
way. 
There are no eccentricities or compli- 
cations in the leaves of the wood-rushes, 
which are flat, hairy and grass-like. 
The flowers of all the rushes are borne 
in a large, loose cluster. 
This cluster generally tops the stem, 
and beside the flowers are a pair or trio 
or circle of slender, green spears, which 
Fic. — 7 : : 
Measine together constitute the ‘‘involucre.” 
wise sec- : 
tion of In the common ‘‘soft-rush’’ the in- 
the tubu- a6 * 
larleafof Volucre consists of a single leaf. 
ra ae This pokes up aggressively, prolonging 
eee the line of the stalk, so that the flower 
cluster is thrust from its place and dangles down 
sidewise. But, despite appearances to the contrary, 
the blossoms crown the stem, after the custom of 
the rushes, and all above them is a single ‘involu- 
cral leaf.” 
The flowers of the wood- and water-rushes are 
all of the same lily-like type. There are three 
