Gan fod y dwr yn llawn mwynau cyfoethog, mae llawer iawn o blanhigion prin wedi cael llonydd i dyfu yno. Dyma rai ohonynt: y llemfrwynen (Cladium mariscus), y gorsfrwynen ddu (Schoenus nigricans), y frwynen glymog (Juncus subodulosus), y gorsen gyffredin (Phragmites communis), helygen Mair (Myrica gale) a glaswellt y gweunydd (Molinia caerulea). Yn ogystal, ceir sawl math o degeirian. Yn eu plith ceir tegeirian y gors culddail (Dactylorchis traunsteineri) a’r tegeirian pryfyn (Ophrys insectifera), y ddau’n anghyffredin iawn. 

Bodeilio is a nationally important marsh/mire situated in a shallow valley between Pentraeth and Llangefni. This is one of four important mires in Anglesey, as it has calcareous mire - which is very rare in th U.K.

As this mire has very rich water,  all kinds of rare plants grow in the marsh; such as Cladium mariscus and orchid flora which includes the uncommon narrow-leaved marsh orchid (Dactylorchid transteineri) and fly orchid (Ophrys insectifera).