Seeds from Thunbergia Alata Sunrise Yellow. This tender perennial climber is evergreen in Zones 10 and warmer. Brightly displaying 1.5 inch flowers in shades of bright yellows cover this fast growing vine. The blossoms have a 5 petals surrounding a brownish purple center. Where grown as an annual, plants can reach 8 feet. When grown as a perennial up to 20 feet. Zones 9 to 11.