Mos­ses are small plants that can form cushions, mats, or loose pat­ches on soil, rock, bark, and other sur­fa­ces. The­ir modest size makes them easy to pass witho­ut noti­ce, yet a clo­se view reve­als con­si­de­ra­ble varie­ty. A patch that appe­ars to be one gre­en textu­re may con­ta­in seve­ral forms. Its appe­aran­ce also chan­ges as the plants beco­me wet­ter or drier under dif­fe­rent conditions.

Mos­ses do not have the same inter­nal trans­port struc­tu­res as typi­cal tre­es and flo­we­ring herbs. Water can be taken up across the­ir sur­fa­ces, and the­ir growth is clo­se­ly rela­ted to moistu­re in the sur­ro­un­ding envi­ron­ment. Small struc­tu­res cal­led rhi­zo­ids help attach them to a sur­fa­ce. The­se sho­uld not be assu­med to func­tion exac­tly like the exten­si­ve root sys­tems of lar­ger plants, even tho­ugh both can help keep a plant in place.

Repro­duc­tion inc­lu­des the pro­duc­tion of spo­res rather than flo­wers and seeds. In many mos­ses, spo­re-bearing cap­su­les rise abo­ve the leafy growth on slen­der stalks. The­se struc­tu­res can make a patch look quite dif­fe­rent at cer­ta­in times. Moistu­re also plays an impor­tant role in other sta­ges of the life cyc­le. The visi­ble leafy plants are the­re­fo­re part of a bro­ader sequ­en­ce that is not ful­ly repre­sen­ted by the­ir eve­ry­day appearance.

A moss patch cre­ates its own small-sca­le con­di­tions. The spa­ces betwe­en sho­ots can reta­in moistu­re and shel­ter tiny orga­ni­sms. The sha­pe of the under­ly­ing sur­fa­ce affects how water col­lects or dra­ins away. A sha­ded side of a wall may sup­port growth dif­fe­rent from that on a near­by expo­sed sto­ne. The­se dif­fe­ren­ces can be sub­stan­tial even tho­ugh the two pla­ces are sepa­ra­ted by only a short distance.

Care­ful obse­rva­tion works best at the sca­le of the plants them­se­lves. Chan­ges in colo­ur, the sha­pe of indi­vi­du­al sho­ots, and the pre­sen­ce of cap­su­les can all pro­vi­de use­ful deta­ils. A magni­fied view may reve­al struc­tu­res that are invi­si­ble in a gene­ral land­sca­pe pho­to­graph. Mos­ses show how living com­mu­ni­ties can occu­py small sur­fa­ces and how the inte­rac­tion of moistu­re, sha­de, and textu­re pro­du­ces varie­ty in pla­ces that might other­wi­se seem ordinary.