TERMINOLOGY: 49 
cous; deciduous or persistent. The lime tree, Tilia 
europea, aftords an excellent example of the Brac- 
tex. When they are of another colour than green, 
they are said to be coloured, (coloratee). On the 
top of many | flowers there are several of these brac- 
te, in which case they are called a tuft, (coma.) 
Examples of this we have in the crown imperial, 
Fritillaria impe -rialis, the pine apple, Bromelia Anan- 
oa 
§ 90 
The SHEATH, (vagina), is the prolongation of a 
leaf, which rolls itself round the stem, and thts 
forms a cylinder, | to the opening of which the leaf 
1s attached, as in Polygonum, and all the Grasses. 
When this sheath is very short, and on the upper 
part of it there is nothing remarkable, it is called a 
sheathing leat, ( folium vaginatum). ‘The vagina is 
also described aceording to its surface, § 6. 
G 31. 
The SPATHE, (spatha), is an cblong leaf, which 
surrounds the’ stem with its base, and serves for a 
covering to flowers before they blow; but after the 
flowers are unfolded it stands at a greater or less 
distance from them. It i is common to all palms, to 
most lilies and arums. Of it there are the following 
kinds. 
1. Univalve, (univalvis), when it consists bus ot 
one leaf, as in Arum maculatum, fig. 41. 
2, Bivalve, (bivalvis), when two leaves stand op- 
D posite 
