Common houseplants are usually tropical or semi-tropical epiphytes, succulents or cacti. Cacti and other succulent fruit are fruits that come from either cacti or succulents. Matorral is characterized by woody shrubs, small trees, cacti, and succulents. There were over 300 varieties of plants, including succulents and cacti. They include acacia trees, palms, succulents, spiny shrubs, and grasses. Cacti (and other succulents) and flax seeds are especially rich sources of mucilage. Mealybugs are one of the most common pests of cacti and succulents. The north wing hosts the extensive collections of ferns, cacti, and succulents. The dogbane/milkweed family includes annual plants, perennial herbs, stem succulents, woody shrubs, trees, or vines. It specializes in orchids and succulents. On the tidal flats behind the mangroves, hardy succulents (samphire), grasses and sedges grow. Plants adapted to living in dry environments such as succulents are termed "xerophytes". "K. spekii" feeds on small flowers, leaves, grass, herbs, succulents and fungi. In some cases, especially with geophytes, plants closely related to the succulents are normal herbs. It also favors succulents and thistles.