For she that hath, to her shall be given…Implications of flowering in Anemone nemorosa L.

Abstract

We looked for life-history trade-offs between flowering, vegetative growth and somatic maintenance in the common woodland herb Anemone nemorosa. A. nemorosa forms a horizontal rhizome system consisting of previously formed annual segments and terminated by a flowering or non-flowering shoot. Resources acquired by the aboveground parts are used for flowering, seed production, storage and growth of the annual segments. Resources stored in the rhizome during the growing period are used for preformation of buds, somatic maintenance between two growing periods and development of aboveground parts in the following spring. We hypothesised that the decision to invest in flower buds depends on the amount of resources stored in the recently formed annual segment. We also hypothesised a trade-off between flowering and segment growth and, finally, as a consequence, we expected individual rhizomes to alternate between the flowering and the non-flowering state. We found that segments producing flower buds were significantly longer than non-flowering segments, indicating that resource level influences the function of the preformed buds. Contrary to our expectations, we found flowering rhizomes produced longer annual segments than non-flowering rhizomes. We suggest the larger leaf area of flowering rhizomes and occasional abortion of flowers or seeds as possible mechanisms behind this pattern. Our study shows that even though the decision to produce a flower bud is taken in another time-frame than that in which the actual flowering and fruiting takes place, an ostensibly inexpedient decision is changed to a neutral or even an advantageous incident.

The consequences of demand‐driven seed provisioning for sexual differences in reproductive investment inThalictrum occidentale(Ranunculaceae)

“…In contrast to demand‐driven investment in fruits and seeds, flowers seem to have been produced from a fixed resource investment, as neither partial defoliation nor partial flower removal affected photosynthate translocation to flowers in either sex, after accounting for variation in flower mass (Table c). Such fixed investment in flowers may indicate that they are produced from stored resources (Muller ; Kudo, Ida & Tani ) and that flower primordia are preformed during the previous growing season (Worley & Harder ; Jones & Watson ; Werger & Huber ; Pontoppidan, Petersen & Philipp ), both of which are common for forest herbs that flower early during the growing season. Whatever the cause of the fixed reproductive investment during flowering, it contrasts with the demand‐driven investment during fruiting by females and indicates somewhat divergent reproductive policies between the sexes.…”

Inflorescence preformation prior to winter: a surprisingly widespread strategy that drives phenology of temperate perennial herbs

“…Our knowledge on bud preformation in herbaceous species has been largely limited to case studies of individual organ‐preforming species (Scribailo & Tomlinson, 1992; Geber et al ., 1997a; Watson & Lu, 1999; Ehrlén & van Groenendael, 2001; Jones & Watson, 2001; Werger & Huber, 2006; Pontoppidan et al ., 2011). Absence of the comparative approach thus precludes drawing conclusions about the role of organ preformation compared with their nonpreforming counterparts.…”