Camptocarpus semihastatus is a species of plant in the Apocynaceae family. It is native to Madagascar.[1] Jens Klackenberg, the botanist who formally described the species named it after the distinct coronal lobes of its flowers that resemble half the head of a spear (Latin: hasta in Latin).[2] [3]
It is a climbing plant. Its elliptical to egg-shaped leaves are 3.5–7 by 1–3 millimeters. The tips of its leaves sometimes come to a long, tapering point. The bases of the leaves are wedge-shaped to tapering. Its petioles are 3–13 millimeters long. Its many flowered, branching Inflorescences occur at the junction between the leaves and stem. Each flower is on a pedicels that is 3–6 millimeters long. The pedicels have bracts that are 1 millimeter long. Its flowers have 5 hairless sepals that are connected at the base with broad, egg-shaped lobes that are 0.7–1 by 0.7–1 millimeters. The sepals have pointed tips. The 5 hairless, white to rose-colored petals are fused at their base to form a 0.8–1.2 millimeter tube with oblong lobes that are 2.8–3.4 by 1.1–1.6 millimeters. The petals have rounded tips. The flowers have a ring-like structure between the petals and its stamen called a corona. Its corona has 5 thread-like lobes that are 2–3 millimeters long with appendages at the top that point inwards. Its stamen have very short, 0.1 millimeter-long, filaments and 0.5–0.6 millimeter long anthers. The anthers have a recurved appendix at their base. The connective tissue between the chambers of the anther extends up into a rounded tip. Its pistils have broad, cone-shaped stigma.[3]
The pollen of Camptocarpus linearis is shed as permanent tetrads.[4]
It has been observed growing in forest and shrub habitats at elevations of 500 to 1499 meters.[3]