Oh no, not a tree. It's Chondrus Crispus. So now you know. I can tell it was on the tip of your tongue.I have no clue what Irish Moss is... now I understand it is a tree
You are closer to Irish Moss than you think. I use to pick it off the rocks, dry it and sell it to a processing plant. Use to eat some of it too. Sort of like dulse but different. Great brain food, along with sardines, eel and lobster.
The lifecycle of C. crispus: Below the life stages are indicated if the life stage is haploid or diploid (2n) and the type of carrageenan present.
How the lifecycles of C. crispusmight look in nature: The gametophytes show blue iridescence and the fertile sporophytes exhibit a spotty pattern.
C. crispus is an industrial source of carrageenan, which is commonly used as a thickener and stabilizer in milk products such as ice cream and processed foods, including lunch meat. In Europe, it is indicated as E407 or E407b. It may also be used as a thickener in calico printing and paper marbling, and for fining beer or wine. Irish moss is frequently used with Mastocarpus stellatus (Gigartina mamillosa), Chondracanthus acicularis (G. acicularis), and other seaweeds, which are all commonly found growing together. Carragheen and agar-agarare also used in Asia for gelatin-like desserts, such as almond jelly. Presently, the major source of carrageenan is tropical seaweeds of the genera Kappaphycus and Eucheuma.
In Ireland and parts of Scotland (where it is also known as (An) Cairgean in Scottish Gaelic), it is boiled in milk and strained, before sugar and other flavourings such as vanilla, cinnamon, brandy, or whiskey are added. The end product is a kind of jelly similar to pannacotta, tapioca, or blancmange. Similarly, in Jamaica and Trinidad and Tobago, Gracilaria spp. are boiled with cinnamon and milk to make a thick drink called Irish moss that is believed to be an aphrodisiac. In Venezuela it has been used for generations as a home remedy for sore throat and chest congestion, boiled in milk and served with honey before bed.
Irish moss is commonly used as a clarifying agent or finings in the process of brewing (beer), particularly in homebrewing. A small amount is added to the kettle or "copper", where it is boiled with the wort, attracting proteins and other solids, which are then removed from the mixture after cooling along with the copper finings.