Lawsonia inermis 0.5–2 cm or 0.6–2 in x 0.2–0.8 in), acuminate (tapering to a long point), and have depressed veins on the dorsal surface. Henna flowers have four sepals and a calyx tube, with spread lobes. Its petals are obvate, with white or red stamens found in pairs on the rim of the calyx tube. The ovary is four-celled, long, and erect. Henna fruits are small, brownish capsules, in diameter, with 32–49 seeds per fruit, and open irregularly into four splits. The henna plant is native to northern Africa, western and southern Asia, and northern Australia, in semi-arid zones and tropical areas.
Calyx of Held embryonic calyx formation. One characteristic that distinguishes Eph proteins and their receptors from other signaling systems is their ability to transmit information bidirectionally. Forward and reverse signaling in VCN and MNTB cells is essential for the proper number and formation of VCN and ipsilateral MNTB projections in the calyx. Eph proteins also ensure that while axons pass through the ipsilateral MNTB, branching and final termination of these projections only occur in the contralateral MNTB, possibly because the proteins are only targeted towards specific regions on the axons. Overall, there are two ultrastructural changes that occur in the calyx of Held.