The Collaborative International Dictionary of English v.0.48:

Stalagmite \Sta*lag"mite\ (st[.a]*l[a^]g"m[imac]t), n. [Gr.
   sta`lagma that which drops, a drop, fr. stala`zein to drop:
   cf. F. stalagmite.] (Geol.)
   A deposit more or less resembling an inverted stalactite,
   formed by calcareous water dropping on the floors of caverns;
   hence, a similar deposit of other material.
   [1913 Webster] Stalagmitic

WordNet (r) 3.0 (2006):

stalagmite
    n 1: a cylinder of calcium carbonate projecting upward from the
         floor of a limestone cave