Eleocharis ~ separation of confusion pairs:

multicaulis versus quinqueflora


Shared features

  • tufted
  • the basal glume +/- surrounds the base of the spikelet
  • stigma 3-forked
  • may grow in similar open seepage areas in mineral-influenced mires, sometimes in close proximity


Separation

Should not present problems when shoots are mature, as multicaulis is a more substantial plant, and typically has more the ‘look’ of larger species. More tricky when slender, and/or immature: in young spikelets the basal glume is a greater proportion of the spikelet.

Readily separated on:
~
length of basal glume versus length of (mature) spikelet:
          
multicaulis has the basal glume about 1/4 the length of the spikelet (left, below)
          
quinqueflora has the basal glume about 1/2 the length of the spikelet (right, below), or even more

~
spikelet with more flowers in multicaulis, making a longer spikelet

~
upper leaf-sheath opening:
          
multicaulis has an obliquely-cut opening, creating an apex (about 90 degrees, or 'sharper'); see figure in species account of multicaulis
          
quinqueflora has a +/- transverse/truncate opening

      
multicaulis                        quinqueflora


~
basal glume (often?) notched at apex in multicaulis (below); rounded in quinqueflora



~
style-base constricted at attachment to nut in multicaulis (below, left); confluent with nut in quinqueflora (below, right)


nuts: multicaulis (left); quinqueflora (right)
(not quite to scale)

~ multicaulis stouter with wider stem

Summary


multicaulis

quinqueflora

basal glume: length vs. length of spikelet

approx. 1/4
1/2 or more
basal glume: apex
often notched, hence bilobed
rounded, not notched
style-base
wide at junction with nut, with ‘neck’
narrow; confluent with nut, no ‘neck’
flowers in spikelet
10 or more
7 or fewer
nut
rather small: to 1.5 mm
larger: 2 mm or more
stem diameter
typically 1 mm or more
usually less than 1 mm
upper leaf-sheath opening
oblique/slanting; has an apex
truncate; no apex

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