Description: — Twining perennial, climbing up to 5 m high, with deep root system, with swollen tuberous taproot. Stems covered in short soft hairs. Leaves compound, with 3 leaflets orbicular to rhombic, leaflet apex acute, margins entire, often covered with hairs, venation pinnate; petiole ± 2.5 – 8.5 cm long. Inflorescenses racemes, up to 30 cm long. Flowers zygomorphic, on short pedicels, bisexual; calyx with 5 fused, pubescent, greenish sepals that form short tube; corolla with 5 dark purple to black petals, fused at their base, 2 petals form keel, single large standard petal. Fruit elongate linear legume, twisting as it matures, elastically dehiscent, explosive, skinny, cylindrical, 5 – 10 cm long, pubescent, ripen from green to tawny brown. Seed 12 – 15, small, light brown to black (Fig. 5). Habitat and human impacts on the recorded plant Island: — Macroptilium atropurpureum is recorded on two islands (El Tawaysa Island and Mansouryia Island). El Tawaysa Island: The west bank of the island is located about 100 m from the mainland. Water in this direction is shallow and stagnant, so the sites that were studied at this side are characterized by an abundance of submerged, free-floating, and emergent macrophytes. Cultivated fields, fishing areas, and inhabited sandy and stone areas are the habitats identified on this island. Human impacts on this Island were represented by fishing and agricultural activities. The second Island (Mansouryia Island) has the largest area in the first-reach region. The island is located near the west bank. Since the island is located in the inner curve, the island nearly tends to merge with the west bank (Raslan & Salama 2015). Cultivated fields, fishing areas, and inhabited sandy areas are the habitats identified on this island. Associated species recorded are Emex spinosa (L.) Campd., Imperata cylindrica, Lawsonia inermis L., Phragmites australis, Phyla nodiflora (L.) Greene, Pluchea dioscoridis (L.) DC., Rumex spinosus L., Sesbania sesban (L.) Merr., Tamarix senegalensis DC., and Withania somnifera (L.) Dunal. Human impacts on this island were represented by fishing and agricultural activities. The plant was recorded in both islands in cultivated field habitat. World native and introduced range: — Macroptilium atropurpureum originated in tropical America and has since been introduced to many islands in Oceania, Africa, Asia, the Caribbean, and Australia (Cameron 1985, Acevedo-Rodríguez & Strong 2012). It is introduced to Andaman Is., Angola, Arizona, Bahamas, Brazil North, Brazil Northeast, Brazil South, Brazil Southeast, Brazil West-Central, Burkina, Caroline Is., China Southeast, Christmas I., Cocos (Keeling) Is., Cook Is., Cuba, Dominican Republic, Easter Is., Ethiopia, Florida, Gabon, Hawaii, India, Kenya, Leeward Is., Lesser Sunda Is., Line Is., Madagascar, Marianas, Mauritius, Mexican Pacific Is., Myanmar, Nansei-shoto, New Caledonia, New Guinea, New South Wales, Northern Territory, Puerto Rico, Queensland, Rodrigues, Réunion, Samoa, South China Sea, Sri Lanka, St. Helena, Taiwan, Texas, Tubuai Is., Uganda, Vanuatu, Western Australia, Windward Is., and Zimbabwe (POWO 2023) (Fig. 3).
