| Mr. Brown, on the Proteaceae of Jussieu. | 25 |
From this account of the geographical distribution of the Proceaceæ, I proceed to make some general remarks on the structure and modifications of their different parts. The order, which consists of shrubs of the most rigid nature, or of trees of moderate size, contains also one herbaceous plant, my Symphionema paludosum, which however, except in this respect and in the union of the tops of its filaments, does not remarkably differ from the usual structure of the family.
The pubescence, which is very general in the order, consists either of a short and in many cases nearly impalpable tomentum, or of soft hairs which are either spreading, close pressed, or somewhat crisped, generally simple, but in some genera fixed by the middle, and in a very few cases glandular.
The existence or absence of pubescence in the adult leaves cannot always be depended upon in distinguishing species; but the short tomentum, especially of their under surface, is of greater consequence than the spreading hairs. In the bracteæ more reliance may be placed on it, and in the different parts of the flower I have never hesitated to employ it in my specific characters. In the calyx I have even derived the greatest advantage in some difficult genera, especially Serruria, from attending to its differences in direction.
Mr. Salisbury has introduced the pubescence of fruit into several of his generic characters, and in some I think with evident advantage, but in such only as where from its abundance and length it performs a function of manifest importance in assisting dissemination: hence I conceive it may be safely admitted into the characters of Protea and Isopogon; but I can perceive no advantage whatever in employing it in those of Serruria and Spatalla. For this reason too it ought not to be used in the capsular or drupaceous genera, in which indeed experience
| vol. x. | e | proves |
