Separation of confusion pairs: Eleocharis …

uniglumis versus quinqueflora


Shared features


uniglumis can be slender enough to look superficially similar to quinqueflora
the basal glume surrounds the base of the spikelet
can grow together rarely in upland calcareous mires

Separation

Readily separated on these characters:

length of basal glume versus length of spikelet:
          uniglumis has the basal glume less than 1/5th the length of the spikelet
          
quinqueflora has the basal glume often about 1/2 the length of the spikelet, or even more.

(Beware some
quinqueflora spikelets with a lowest glume shorter than half spikelet length, suggesting uniglumis. See below: in immature plants check stigmas (quinqueflora 3-forked; uniglumis 2-forked), and if mature, check nuts (quinqueflora: slender style-base and no 'neck'; uniglumis: obvious 'neck' below swollen style-base).)


quinqueflora (early season, flowering) showing basal glumes
encircling spikelet base, and half as long as spikelet



uniglumis, showing basal glumes much less than half as long as spikelet


numbers of flowers in spikelet (count glumes; nuts could be counted, but be aware some flowers fail to ripen nuts):
          uniglumis has normally10 or more flowers
          
quinqueflora has 7 or fewer

stigma forking:
          uniglumis 2-forked
          
quinqueflora 3-forked

style-base shape (when nuts ripening) is very distinct:
          uniglumis has style-base very much swollen, with distinct ‘neck’
          
quinqueflora has style-base confluent with nut

         uniglumis


    quinqueflora

Links to the other Eleocharis spike-rush pages (also accessible from the sidebar)