Sentence:  To summarize the characters of a true mushroom - it grows only in pastures; it is of small size, dry, and with unchangeable flesh; the cap has a frill; the gills are free from the stem, the spores brown-black or deep purple-black in colour, and the stem solid or slightly <WSD>pithy</WSD>. 
Meaning of the word marked with <WSD> tags:  Of, like, or abounding in pith.