Assertion: moss's leaf | /r/CapableOf | lack costa
Facets:
Source sentences:
text: Leafy liverworts can be difficult to distinguish from mosses, but their leaves are usually arranged in two rows (rather than spirals) and lack a costa.
text: The leaves of the liverworts lack costa.
text: The leaves of the class Sphagnopsida are one cell thick (unistratose), arranged spirally and lack costa.