The Collaborative International Dictionary of English v.0.48:

Goldseed \Gold"seed`\, n. (Bot.)
   Dog's-tail grass.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Dog's-tail grass \Dog's"-tail grass`\, n. (Bot.)
   A hardy species of British grass (Cynosurus cristatus)
   which abounds in grass lands, and is well suited for making
   straw plait; -- called also goldseed.
   [1913 Webster]