The word arthrosporous is playable in Words With Friends™, no blanks required. Because it is longer than 7 letters, you would have to play off an existing word or do it in several moves.
Words With Friends™ Letter Score: 19
Highest Scoring Words With Friends™ Play In The Letters arthrosporous
:
Seven Letter Word Alert: (22 words)
apthous, authors, horrors, hotspur, orators, outraps, outroar, outsoar, outspar, parrots, passout, pastors, protura, raptors, sophtas, soursop, sprouts, stupors, torpors, uproars, uproots, upshots