Helianthus debilis aka Beach Sunflower

Helianthus debilis, also known as cucumberleaf sunflower, beach sunflower, weak sunflower, and East Coast dune sunflower, is a species of sunflower native to the United States. It can be found along the Atlantic and Gulf Coasts and has also been introduced to countries such as South Africa, Australia, Taiwan, Slovakia, and Cuba. This plant can be either an annual or perennial herb, reaching a height of up to 2 meters. It has alternate leaves that vary in shape and size, with the largest measuring up to 14 centimeters long by 13 centimeters wide. The showy inflorescence consists of one or multiple flower heads, with up to 30 lance-shaped phyllaries and 20 or 21 ray florets. The color of the florets can range from yellow to whitish, reddish, or orange. The center of the flower head is filled with red, yellowish, or purplish disc florets. The fruit is a small cypsela measuring around 2 or 3 millimeters long. There are several subspecies of Helianthus debilis, including Helianthus debilis subsp. cucumerifolius, which has the widest distribution, and Helianthus debilis subsp. debilis, which is endemic to Florida. Another subspecies, Helianthus debilis subsp. silvestris, is endemic to Texas, while Helianthus debilis subsp. tardiflorus is limited to rare coastal habitats from Mississippi to Florida. The subspecies Helianthus debilis subsp. vestitus, also known as clothed sunflower or hairy beach sunflower, is endemic to Florida and is considered imperiled. Helianthus debilis is well-suited for coastal habitats and can grow directly on the beach, tolerating moderately saline environments but not excessive salt spray or inundation. It is highly drought-tolerant and can thrive in low-nutrient and poor soils, including alkaline, acidic, and sandy soils. The plant attracts butterflies, and birds feed on its fruits. In addition to its natural habitat, Helianthus debilis is commonly used as a garden flower and is suitable for landscaping, particularly in poor and dry soils. It is often planted on beaches to prevent erosion and stabilize dunes. While it rarely requires supplemental watering, it may appear less attractive after the flowers have withered. Cultivars of Helianthus debilis include 'Italian White', 'Flora Sun', 'Dazzler', 'Excelsior', and 'Orion'. The 'Italian White' Sunflower is a branching and prolifically flowering variety with small pale creamy-yellow blooms, featuring darker centers and deep green bristly leaves. It grows on tall stems reaching 1.2 meters and is commonly used as a cut flower or for long summer displays in gardens. As a houseplant, the 'Italian White' Sunflower is rare and requires regular watering. It thrives in direct light, preferably within 1 foot of a window. Well-draining soil is recommended, and repotting is necessary when the plant doubles in size, eliminating the need for additional fertilizers.