The Collaborative International Dictionary of English v.0.48:

Stichidium \Sti*chid"i*um\, n.; pl. Stichida. [NL., fr. Gr. ?,
   dim. of ? a row.] (Bot.)
   A special podlike or fusiform branch containing tetraspores.
   It is found in certain red algae.
   [1913 Webster]