SUMMER MOSSES ARE TOUGH LITTLE SURVIVORS

Late spring is an exciting time to spot nesting birds arriving back -- birds like tri-coloured heron and limpkin in Barrie and Angus wetlands that should be in Florida swamps nesting at this time of year.

Soon, I will be taking naturalist groups to see rare orchids in full bloom in Bruce and Simcoe counties. Alvars will be at peak bloom for rare alvar flora when we visit them this month.

But I don't want you to overlook the exciting little mosses that cover the alvars, as well.

Most are only two centimetres tall and tightly packed together in tufts, cakes, cushions, carpets or pads in full sun on flat limestone bedrock. They survived the spring alvar floods and now will survive the dry conditions and intense summer sun.

Mosses don't have vascular bundles to conduct water from roots up into leaves like vascular plants; they move water by capillary action, so they need to be small. They have rhizoids that anchor them to the substrate, but don't absorb water or nutrients from substrates like plant roots and rhizomes.

They also reproduce mainly by branching and fragmentation regeneration (small open cups on their surface contain vegetative reproductive fragments called gemmae) or by spores, not seeds like most plants.

Mosses on alvar form cakes on bare limestone containing up to half a dozen moss species tightly packed together on the hot rock, with little rain during the summer.

The study of these miniature moss cakes is fascinating and amazing, with interesting and descriptive common names. Wiry fern, tall-clustered thread, bristly star, twisted star, talon, tall tornado, prickly cannikin, bordered thyme, toothless cup, stubby mousetail, candle snuffer and bendy cow-hair moss are just a few of the species you may find in a moss cake.

It's a small, amazing world right under our feet on bare rock.