roble vs valley oak

roble and valley oak both are nouns.

Word	Noun	Adjective	Verb	Adverb
roble	Yes	No	No	No
valley oak	Yes	No	No	No

As nouns, roble and valley oak are synonyms defined as:

roble and valley oak: tall graceful deciduous California oak having leathery leaves and slender pointed acorns

Other synonyms of roble include California white oak, Quercus lobata, valley white oak.

roble (noun)	valley oak (noun)
tall graceful deciduous California oak having leathery leaves and slender pointed acorns	tall graceful deciduous California oak having leathery leaves and slender pointed acorns
large tree of Trinidad and Guyana having odd-pinnate leaves and violet-scented axillary racemes of yellow flowers and long smooth pods; grown as a specimen in parks and large gardens