Impatiens plants are more patient with siblings

Jewelweeds crowd out the competition but make room for their kin

Jewelweeds make nice with their leaves when their roots share roots.

MODEL SIBLING Yellow jewelweeds, wildflowers that cluster along shady watersides in eastern North America, apparently can recognize their siblings as long as roots share soil. pellaea/Flickr

QUIZ TIME An array of jewelweed seedlings in tall pots let researchers test for effects of growing near siblings or non-siblings.