Retired professor of math and computer science having taught for 36 years at a state supported university in Virginia. United States Senators serve a term of six years in office. There is no limit on how many terms a Senator can be elected to serve.
Herbaceous perennials are garden plants that die back to the soil line when winter temperatures arrive. The plants enter a dormant period and strengthen the root system while waiting for the coming of spring.
The hibiscus genus includes both annual and perennial herbaceous plants, as well as woody shrubs and small trees. The varieties commonly sold in catalogs and garden centers in the US are usually perennials, as they come back year after year, especially in warmer growing zones.