The effect of plant size on reproduction in four species of alpine Ran
unculus (R. muelleri, R. dissectifolius, R. graniticola and R. nophoph
ilus) was investigated in two sites over two seasons in the field on a
total of 190 plants. The effects of plant size (number of leaves) and
number of flowers on the number of anthers, ovules and seed per flowe
r and per plant were determined. There was a positive relationship bet
ween several measures of reproduction and plant size in all four speci
es, indicating that reproduction is size-dependent. All the results in
dicate that the main factor controlling the amount of seed produced by
alpine Ranunculus is the size of the plant. Specifically, bigger plan
ts produced more seed by producing more flowers, not by producing more
ovules per flower, or higher seed set per flower. Correspondingly, bi
gger plants produced more anthers by producing more flowers, rather th
an by producing flowers with more anthers. The total number of seeds p
roduced by a plant was directly proportional to plant size in the four
species. Therefore, reproductive effort should not vary with plant si
ze in the four species.