Select large, clean plants by pinching off the branches. Leave the bottom portion (stem) behind. Wash the plant in water to remove dirt and small animals.
Wrap the plant in taro leaves or inside a sugar sack. Keep the wrapped plant in the shade or refrigerator. Plants can be frozen, but thawing out causes the plant to wilt and turn dark brown but enhances flavor.
botany.hawaii.edu
The spiny sea plant has narrow arching branches that grow spirally around the stem. It can be greenish, golden or purplish-brown in color. Spiny sea plants grow all year round and grow best on reefs and in tidal pools, river mouths and lower intertidal areas (Novaczek, 2001).