Cosmos longipetiolatus  Cosmos longipetiolatus is a Mexican species of plants in the sunflower family. It has been found only in the state of Jalisco in southern Mexico. "Cosmos longipetiolatus" is a branching perennial, producing thick, tuberous roots underground. Leaves are highly divided into many small lobes and leaflets. Each plant produces numerous flower heads, with purple or lavender ray florets and yellow disc florets.