You are not currently logged in.
Access your personal account or get JSTOR access through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Developmental Ecology of Mayapple: Effects of Rhizome Severing, Fertilization and Timing of Shoot Senescence
H. De Kroon, D. F. Whigham and M. A. Watson
Vol. 5, No. 3 (1991), pp. 360-368
Published by: British Ecological Society
Stable URL: http://www.jstor.org/stable/2389807
Page Count: 9
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
Mayapple (Podophyllum peltatum (L.)) is a perennial herb that forms rhizome systems, each terminated by a vegetative or sexual shoot. Such systems consist of previously formed annual segments, that are kept alive for many years. By severing rhizomes and fertilizing shoots, we have investigated whether new rhizome growth depends on nutrients acquired by roots of older segments. The treatments were imposed in spring and the effects evaluated in the following autumn, when formation of new rhizomes was complete. Neither severing alone, nor the combination of severing and fertilization significantly affected rhizome branching, determination of the new rhizome bud type, rhizome length or dry weight. Fertilization and even severing alone increased the accumulation of nutrients in new rhizomes. Timing of shoot senescence had a major impact, with later senescing shoots producing longer and heavier new rhizomes. Later senescence also increased the biomass increment of the penultimate rhizomes, i.e. those immediately preceding the current year's shoot. We conclude that in mayapple nutrient uptake by older roots does not contribute, at least immediately, to new rhizome growth. The lack of fertilization effects and the presence of strong effects of the timing of shoot senescence upon new rhizome growth indicate that light rather than nutrients was the limiting factor in this growth phase. The increased nutrient accumulation in response to fertilization suggests, however, that growth of the rhizome system may be affected by nutrient availability over a longer period of time. Data are presented that suggest that rhizome segments store nutrients that are needed to support the growth of developing shoots in subsequent years. Given the capability of dormant buds on old rhizome segments to form new shoots after damage, an important function of rhizome longevity in may-apple may be to maintain the potential to regenerate.
Functional Ecology © 1991 British Ecological Society