| Between Arenaria leptoclados on the one side and A. serpyllifolia s.s. (including subsp. macrocarpa) on the other a difference exists in the structure of the mature, dry capsules. In A. leptoclados these usually have a dented or pleated appearance. When compressed between finger nails they flatten without breaking, or with some crumbling only. The dry capsules of A. serpyllifolia, however, are usually smooth. They are brittle and respond to pressure applied to the top part of the capsule by snapping open lengthwise. Usually they disintegrate entirely. Transverse sections of the mature capsule wall differ in absolute thickness (40-150 µm in A. serpyllifolia; 15-30 µm in A. leptoclados in sections taken through the middle portion of the fruit), as well as in... |
