There are also ephemeroids, plants with underground perennating organs that complete their growth cycle when the environmental conditions are favorable.
Ephemerals and ephemeroids are plants that are well adapted to life in the deserts and to dry summers.
The temperate deserts have a large variety of spring ephemeroids with underground storage organs.
The large umbellifers of the genera Ferula and Dorema are typical monocarpic ephemeroids.
Another species of ephemeroid is Zygophyllum [=Miltianthus] portulacoides, which grows in the gypsum deserts and has similar tuberlike roots and greatly reduced petals.
Orchids are very infrequent in deserts, but in the tokay of the Turan lowland, Afghanistan, and Iran, there is a rhizomatomous ephemeroid orchid, Zeuxine strateumatica, whose shoots have a very short growing cycle (45-50 days).
Many parasitic species such as the species of Cistanche (Orobanchaceae) are also characterized by an ephemeroid growth-form.
Some of these ephemeroid grasses hardly ever produce any seeds and instead reproduce vegetatively or by viviparity, forming bulbils within the inflorescences or in the leaf axils.
Thus, the zones the herds graze in spring are rich in
ephemeroids, while in winter they move to sites dominated by artemisias, as these typical desert plants tend to reach their greatest size in the autumn.
Extensive studies have focused on the relationship between plants and soil; however, few reports were performed to investigate the morphological plasticity of ephemeroid plants in response to water deficiency in desert environment.
This research will shed light on the ecological adaptive strategies of the clonal integration of the ephemeroid rhizomatous species C.
Carex physodes is an ephemeroid sedge, 15-35 cm tall (Figures 1(a) and 1(b)).