| Crocus alatavicus is a geophytic-geocarpic species which flowers in the early spring as a ephemeral. This species is mainly distributed in the subalpine zone of the western Tianshan Mountain. The propagation mode, breeding system, pollination biology, and the characteristics of fruiting and seeds dispersal were studied in the field, and its adaptive strategies to the subalpine environment were analyzed. Our aims were to supply some evidence for understanding propagation mode and dispersal feature, and explore the ecological adaptative significance of geocarpy in plants. The main results are as follows:(1)Sexual reproduction is the main reproduction mode of C. alatavicus. Each plant can produce 1~4 new corms, but most of them are one. The fruit-set of C. alatavicus was 62.46±7.31% and seed-set was 53.39±2.74%. The peduncle would elongate and raise the fruit above the level of soil, and then the capsule dehisced.(2)Flowering began in early- to mid-April and its flowering pattern is hysteranthous and explosive at the population level. The inferior ovary is below ground at anthesis, while the other parts of the flower are aboveground. The flowers were open during the day and closed at night, and individual flower duration was 6~9d. Pollen viability was 75.39±5.69% at the end of anthesis, and stigma receptivity could last 8d. The results of artificial pollination experiments suggested that the breeding system of C. alatavicus is facultative xenogamy with the ability to self-pollinate spontaneously.(3)Crocus alatavicus had a generalist pollination system, and Bombus lucorum, Anthophora senilis and Andrena capillosa were its effective pollinators. These insects pollinated by foraging pollen and their visiting frequencies were 0.50±0.27, 0.18±0.08 and 0.13±0.05 per flower per hour, respectively. Bombus lucorum was the first pollinator to visit the flowers and had the highest visiting frequency among the three pollinators during the day and the flowering season. (4)The seeds with elaiosome were dispersed by ants, and its dispersal mode belonged to a short dispersal strategy. Formica pressilabris, Formica gagates and Formica fusca were its effective dispersal. Formica pressilabris dispersal distance was the longest, and its occurrence time was the most among the three ants during the dispersal season.Crocus alatavicus not only has evolved the corresponding flowering pattern and generalist pollination system, but it also utilizes an otherwise vacant niche in the early spring season to improve the effectiveness of pollination. Furthermore, the characteristics of its breeding system, such as self-compatibility and spontaneous self-pollination, ensure reproductive success of this species when the pollinators are scarce and their visitation frequencies are low in early spring in the subalpine zone of western Tianshan Mountain. In addition, its vegetative propagation could maintain persistence of population. Moreover, its features of geophytic geocarpy and dispersed by ants, could not noly ensure development of fruit and safety of seeds, but also enlarged population and avoided sib-competition.
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