The expectations that shade-tolerant forest species show 1) a population structure composed by a high amount of small individuals, and 2) biomass allocation for diameter higher than for height growth, were tested for Rudgea parquioides, a typical shrub in Southern Brazil. We described the size structure (height and stem diameter) and allometrical relations of a R. parquioides population by counting and measuring all the individuals in a 725m(2) area in the municipality of Curitiba (25°25'S; 49°19'W). A total of 916 individuals (12,634 ind.ha(-1)) were recorded in the area. The first expectation was supported, since distribution by height and diameter classes showed a predominance of small individuals (skewness coefficients > 1). On the other hand, the regression between height and stem base diameter showed slope β < 1, which indicates that growth in height is higher than in diameter, not supporting the second expectation. These results show that life strategies in shade-tolerant species may imply in more trade-off combinations than previously described.