Klemow, Kenneth M. and Myron W. Yencha 1985. DEMOGRAPHY OF THE CLONAL PERENNIAL HIERACIUM FLORENTINUM IN AN ABANDONED LIMESTONE QUARRY. Contributed paper: Pennsylvania Academy of Science meeting. Abstract: Proceedings of the Pennsylvania Academy of Science 59:79.
Yellow hawkweed (Hieracium florentinum (Asteraceae) is an herbaceous, perennial plant species that reproduces both by seeds and clonally by buds formed on the roots. It is one of the dominant species that naturally colonizes a 50-year-old, abandoned limestone quarry near Syracuse, New York. Populations of H. florentinum were monitored on two contrasting sites from 1976 to 1981 to determine the direction and rate of population flux and whether that rate was influenced by site conditions and year-to-year variation in rainfall. The relative importance of seedlings vs clonally produced rosettes to maintaining the population was also determined. On both sites, the total density of rosettes increased slightly during the study, mainly due to recruitment of rosettes from root buds. Recruitment was greatest in 1976, the year with the most abundant rainfall. Seedlings were rare and very few survived to reproduce. Plants on a sparsely vegetated site produced taller stems and were more fecund than plants on a densely vegetated site. The significance of these findings as they relate to community processes and to possible reclamation efforts will be discussed.