|a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison.|
|an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle.|
thallus thal·lus (thāl'əs)
n. pl. thal·lus·es or thal·li (thāl'ī)
A plant body or fungus undifferentiated into stem, root, or leaf.
|thallus (thāl'əs) Pronunciation Key
Plural thalli (thāl'ī)
A type of body found among plants and fungi that is not differentiated into roots, stems, or leaves. Thalli are found among lichens, mosses, liverworts, and many algae, as well as the gametophyte generations of horsetails and ferns, which have rhizoids but not true roots.