Where to look for native grass, the Arch of Spring Author Star jasmine – planted as an ornamental ground cover and as a trellised vine. Star Jasmine's Sweet Perfume, exuded from clusters of small, white flowers, will continue to scent San Diego's spring breezes until sometime in June. Not a true jasmine, or Jasminum, star jasmine belongs to the genus Trachelospermum. In both public and private spaces, it has been widely planted as an ornamental ground cover and as a trellised vine. The wide open space of Ramona Grasslands offers a glimpse of early California. The Annual Green-to-Golden Transition of San Diego's wild grasslands typically takes place in April. North-facing hillsides and canyon slopes retain the green color longer, as they are less exposed to drying sunshine. Locally, most of the wild grasses are naturalized (non-native) annuals, the seeds of which were introduced along with hay and other grains brought in by the Spaniards during the 18th and 19th centuries. Some of the mountain meadows have remnants of native grasses, which remain more or less green almost the year round. These rare native grasslands can be found in certain parts of Cuyamaca Rancho State Park and more widely distributed at the Santa Rosa Plateau Ecological Reserve in the Santa Ana Mountains west of Temecula.