Sorry folks but the plant you have is a moss. It looks like a species of Tortula but there are also other genera of moss that are similar in appearance. Check out this link to an image of what I am seeing this as possibly similar to. Fern prothallia and young sporophytes look much different. Check out the link below for more info on those. Here is a link that might be useful: Fern Life Cycle

First time poster but once I saw this thread just had to post. HANDLE ALL BUSINESS TRANSACTIONS PERSONALLY, CHECK UP ON YOUR BUILDER and know exactly which companies they use so that you can personally check the invoices and accounts :) Speaking from experience, a horrible, terrible experience. We began construction in April 2010 using a Highly recommended builder who was also our Uncle's cousin. We interviewed some of his old clients, some of his current clients, no problems. After we felt confident we signed the contract, got our plans and he began construction. He was professional (receipts, permits etc), the house was coming up in a timely manner and about 3 months in we get a call from the cement company wanting their bill paid. Then we get a call from the Electrician, then the Hvac, then the plumber, lumber company etc....all wanting their money to the tune of $50,000. Then the calls from his other current clients start coming in.... he did the same thing to them. About this time is when he disappears and leaves us with the mess. Remember this was a relative w/ a good reputation. We thought we took every precaution, receipts from him saying everything was paid and only gave him the exact amount he asked for by using a construction loan with a draw type acct...never gave any extra. But he was using our money to cover his other projects since he had went in debt on them too. For some reason the lumber, cement and other companies were STILL giving him in store credit even though he had hundreds of thousands overdue. In court for two years since they tried to sue him but that pond was dry (took his land, house, vehicles everything) but money was still owed so they tried to come after us. Thankfully our receipts, recorded phone calls and misc info saved us. We plan to build again in the future but will personally manage all the money and have a tight reign on everything that happens throughout the building process. And he was "jacking up the invoices" too, by about 40%.... never, ever again will I trust any builder with paying my construction bills. Did I mention we had to replace our roof shingles because they were installed wrong and rotted the wood around the edge? And had to replace the showers because noone waterproofed the walls or sealed the drain so black mold set in? Don't expect inspectors to catch everything either.... Our situation is definitely in the minority but these horror stories do happen.

alaskadiver: Well I printed the info on the link and showed it to the gardener. He said he is pretty sure that is the snake they found behind the waterfalls! He aksed if he could keep the information to show his crew that it was not posionous...but since it said it could climb some 40 feet up high in the trees---now he's going to have to worry about his guys staring up in the trees while they are working on the various yards! :) You mentionted "if our pool borders a river..." well,... Armand Bayou & Nature Preserve (http://www.abnc.org/, borders our neighborhood!! It is a very large Wildlife refuge and wilderness preserve (2,500 acres by us and NASA). So I guess along with the deer that come to our window, we will have to put up with a snake sometime. We have lived in this house for almost 20 years and have only seen the occasional water snake. Thank you so much alaskadiver, for sending the information regarding the snake!! barco & tresw: Thanks for the 'good' info on the pressure washer. Starting with a wide spray pattern would be the way to go...now to find someone to do it! I'm still a little 'apprehenisive' of spending any serious amount of time around the waterfalls!!! So today was the last day of school for the boys & I have a housefull of swimmers celebrating. Hands off the rocks for now. Thanks again for all the input!!!! Now some time for summer fun...oh to be a kid again!!! :)

Hi Bikework. The acid is normally for cleaning mortar and not just for cleaning dirt and grime. Try pressure washing first. Stay far enough away from the stone so that you are not causing any shaling or flaking of the stone with the pressure washer. Unless you are seeking an immaculate look the pressure washing should work just fine. While we view the aging of natural stone as part of the process I do have a client that bleaches their flagstone with a diluted bleach solution. The client's diligence made me chuckle, and they have the cleanest flagstone I have ever seen. As to sealing, we do not seal our natural stone installations. I've attached a couple of pictures of Wisconsin limestone used in a wall and also a path that I previously installed. To my knowledge neither has ever been cleaned with anything other than a hose and broom. Good luck!