As a verifier, I've noticed that many common taxa get entered only with a genus when recorders are typing in common names. Examples are Primrose, Bramble and Hazel which are clearly correctly identified. When I type Hazel into the system the first item in the list is Hazel (Corylus) and the second Hazel (Corylus avellana). Those not familiar with latin binomials understandably pick the first in the list. In some cases the first on the list is not as informative and does not represent the identification sufficiently.
I'm not clear why Primrose has Genus as an option whereas the common name Ivy only maps to Hedera helix. When entering Hedera helix in the system there are several options. Enter Bird's-Foot Trefoil and the first options don't show the latin names so users can't make a decision on whether there is a full binomial. In this case I find most people pick Bird's-Foot Trefoil which maps to Lotus only. Recorders are surprized when I contact them and ask do they mean Lotus corniculatus - Common Bird's-foot-trefoil.
As the list is arranged alphabetically, hybrids can be presented before species in some cases. For instance, if you type in Alka the first return is Alkanet (Anchusa ochroleuca x officinalis = A. x baumaartenii) with Alkanet (Anchusa offinalis) second. This could be baffling for beginners and the most likely answer should be first.
There will be instances where a plant species can only be identified to genus and then recording this is an accurate reflection of their knowledge. This is not the situation I am commenting on here.
It is great to allow such flexibility of name entry in the system and I think this is needed. I think there is also an opportunity to improve the order of presentation and perhaps taxa mapping to common plant names.
A rule has now been implemented which raises the priority of names that are species rank (including ranks just either side of species, e.g. aggregates, s.l. and species hybrid), which should mean that when there is a choice, the species name will appear before other ranks.
The names themselves, and the species and rank which they are matched to, come from UK Species Inventory (UKSI), which is the taxonomic backbone used by iRecord and is maintained by the Natural History Museum, with input from the relevent taxonomic experts. There are some cases in the UKSI where common names map to both genus and species, and others to just one or the other, and inconsistensies like this should be ironed out in due course.