specious vs. spurious

apparently good or right though lacking real merit; superficially pleasing or plausible:

pleasing to the eye but deceptive.

Obsolete. pleasing to the eye; fair.

not genuine, authentic, or true; not from the claimed, pretended, or proper source; counterfeit.

Biology. (of two or more parts, plants, etc.) having a similar appearance but a different structure.

of illegitimate birth; bastard.