JR's Botany Site

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