Sorus

2 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Sorus \So"rus\, n.; pl. {Sori}. [NL., fr. Gr. ? a heap.]
     1. (Bot.) One of the fruit dots, or small clusters of
        sporangia, on the back of the fronds of ferns.
        [1913 Webster]
  
     2.


        (a) In parasitic fungi, any mass of spores bursting
            through the epidermis of a host plant.
        (b) In lichens, a heap of soredia on the thallus.
            [Webster 1913 Suppl.]

From WordNet (r) 2.0 [wn]:

  sorus
       n 1: a spore-producing structure in certain lichens and fungi
       2: cluster of sporangia usually on underside of a fern frond
       [also: {sori} (pl)]