Iva imbricata aka Seacoast Marsh Elder

Iva imbricata has the common name seacoast marshelder. It belongs to the aster family, Asteraceae. Its native range runs from the southeastern United States west to Texas. It also grows wild in the Bahamas, Cuba, and Cayman Islands. This coast plant grows on foredunes, the dunes nearest the sea. It traps sand blown by wind. This helps build low, rounded dunes and holds them in place. These traits help repair dunes and bring them back.

This herb lives for years and looks like a shrub. It has few branches and grows 1–4 feet (0.3–1.2 metres) tall. Its spread can reach 6 feet (1.8 metres). The thick, fleshy leaves have no stalks. Each leaf has a narrow, lance-shaped blade and a tapered tip. Its edges are almost smooth. Early in the season, lower leaves grow in opposite pairs. Later leaves grow one by one near the stem tops. Stems form roots when sand buries them. This can make the plant seem to spread by rhizomes, or underground stems.

Small flowers form racemes, or long clusters, at the stem tips. They bloom in late summer. The clusters grow longer into early fall. The flowers have cream, white, or greenish petals but offer little show. Bracts, which look like leaves, sit below the first flowers. Those that open later have smaller bracts below them. The round fruits are achenes, dry fruits that hold seeds. They range from brown to yellow. Seeds stay in the dry flower calyxes through winter. Calyxes are the outer parts of flowers. Beach winds help scatter seeds as old plant parts break apart.

The plant suits foredune repair sites above the mean high tide line. UF/IFAS reports that plants raised in small pots survived well there. Trials used marshelder alone and with other foredune grasses. Growers have also set out young plants in early spring. Its sand-trapping role gives it value beyond its flowers. The evidence does not show how much cold it can bear. Nor does it show whether it is safe to eat or toxic.

Growers can start plants from seeds or softwood stem cuttings. These young, pliant cuttings can root with no added rooting hormone. In nurseries, cuttings need a growing mix that drains well. Prune young plants to help them branch and grow wider. Do not take cuttings from stem sections with flowers. These lack lateral buds, which grow at the sides. A seed's source can affect its dormancy, or resting state. It can also affect what the seed needs to sprout. One group studied needed cold treatment for seeds to sprout well.