Sentence:  The chief points of difference between specimens of the two are that those of "R. mutabilis" are more setaceous, but less <WSD>aciculate</WSD> on the barren stems, the terminal leaflets are more frequently narrowed at the base, though occasionally they have the ovate form usual in the Plymouth plant. 
Meaning of the word marked with <WSD> tags:  Marked with fine irregular streaks as if scratched by a needle.