3.1. Umbel and club-like organ development
The umbel meristem naked and disc-shaped (~100 μm diameter) at early stages. It fractionates centripetally numerous umbellets and involurcal bracts (Fig. 3a). The center of the umbel remains flat and undifferentiated throughout entire development except last stages. Rarely, the center fractionates the small segments. The peripheral umbellets enlarged fast, which become semi-spherical and unequal (Fig. 3b). The umbellets fractionate floral meristems, followed by incurving towards center of the umbel (Fig. 3c). The center remains flat and naked even after fractionation of inner umbellets into floral meristems (Fig. 3d). It starts to bulge along with fractionation of floral organs. The small bulb-like head with short column, first, initiated. The head restricted by massive floral meristems whose rays and pedicels not enlarged. From side view, it is still not visible due to overtopping by peripheral umbellets (Fig. 3e). Then, its column enlarged along with growing rays of the inner umbellets (Fig. 3f). It grows fast, becomes club-shaped, stands at the umbel center and overtops the umbel plane (Figs. 3g).
The surface of the head is smooth, reticulate and vermiculate with lumens (Fig. 3h). The column is striate and covered by a few small (Fig. 3i) or massive sessile glands (Fig. 3j).