You know that sinking feeling when you’re bryologising in a promising-looking spot. In your hand you have a very slender liverwort – the threadworts are well-named. Resist the strong temptation to discard it and read on…..
The golden rule with identifying Cephaloziella species is to collect material with reproductive structures, otherwise you may as well not bother. The female perianths (bag-like structures) are usually quite conspicuous, the male infloresences (if present), less so. Fortunately, C. stellulifera is typically paroicous, meaning that below the perianth (and capsule, if present) lollipop-like antheridia can be found at the base of the male bracts.
In the field, C. stellulifera has a subtle if distinctive look: its leaves are widely spaced on the stem and when shoots are fertile, both male and female bracts (which are at the top of the shoot and larger than the leaves) can look rather squarrose. Back home, tease out some fertile and sterile stems and check for underleaves with a compound microscope. They are usually quite large (for a Cephaloziella, anyway) and present on all stems (tip – search for them on younger growth as they may erode away on older stems).
If underleaves are present, confirm the presence of antheridia among the bracts below the perianth and finally, confirm that the perianth mouth haslong, narrow cells. If your plants tick all the boxes then it is C. stellulifera. That wasn’t so bad!Read the Field Guide account