How many letters does the top answer for “a shrub or tree of the genus rhus” have?

The most common answer is sumac (5 letters).

Crossword clue: a shrub or tree of the genus rhus

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

sumac 5 letters wn-def

a shrub or tree of the genus Rhus

sumach 6 letters wn-def

a shrub or tree of the genus Rhus

a genus of shrubs and trees; the elder. 60% similar → sambucus