Oct. 31, 2020

Aster family; putting it all together

Pussytoes are a great example of how all those parts add up to a fascinating and complex whole.  Pussytoes have female and male flowers on separate plants.  They spread by sending out runners that root, then produce more flowering stems.  Large patches that are all one plant can result.  And of course, they will be all staminate, or all pistillate.  Most are pistllate.  In this illustration, a pistillate head is on the left.  You can see the tiny pistils with their v-shaped tips.  On the right is a staminate head, with anther tubes that do not include pistils.  Or ovaries.  Since the fuzz of pussytoes is attached to the ovaries, staminate heads are not fuzzy.  Staminate heads are relatively rare.  That is both because the few that are there can put out a lot of pollen, and because the pistillate flowers are perfectly happy if they don't get any.  Those are not only capable of producing seed without fertilization, they prefer that route.  Why all these alternative life styles?  These pussytoes populate open sandy or rocky ground with poor nutrients.  All those adaptations give them a better shot at success.