A Brief Overview of the Sixty Common or Uncommon
Sedges (Carex sp.) of Hamilton/Halton/Peel According to the Brilliant
and Undoubtedly Soon-to-be-Famous Organization Scheme of Carl Rothfels,
Royal Botanist, Esq. With Additional Rare Species of Peel Commented Upon
in the Appropriate Places.
June 13, 2005
Short story – there are a lot of sedges. But,
generally, they look very different from each other – much more
different than Red Maple and Sugar Maple, for example, but we’re less
used to looking at them so don’t remember the differences, or really
know what to look for. Now there ARE certainly groups of species of
sedge that are difficult, don’t get me wrong, just not as many as you
Long story – I’ve divided the common and uncommon
sedges of our area into nine groups (while cheating a bit with a’s and
b’s, etc). This may or many not help. We’ll see. These groups do not
necessarily represent taxonomic groups (i.e. species in a given group
may or may not be closely related to each other).
Group 1: Sedges of wet areas (normally marshes) with upright spikelets, which come off of the main stem.
We’ll start off with an infamous group, the C. aquatilis/C. stricta group. These are thin-leaved tussock-forming sedges
of fens and marsh edges with flat perigynia stacked into tight
cigar-shaped spikelets. You need the basal parts of the plants to
confirm members of this group: C. stricta has ladder-like fibres
connecting the sheaths at the bottom of the plant, C. aquatilis does
not. The easiest way to differentiate them, though, is by the leaf
(a.k.a. “bract”) that comes out from the base of the lowest spikelet. In
C. aquatilis that leaf is substantially longer than the rest of the
inflorescence, whereas, in C. stricta, it is about the same size. C. stricta is common,
C. aquatilis is rare. We could, conceivably, get some
others (C. emoryi, C. lenticularis, etc.), but let’s not get out of
The others in this group have three-sided achenes
(and thus more-or-less rounded perigynia). First there’s C. scabrata,
which doesn’t fit that well into this group, but better than elsewhere.
It grows in shaded wet areas usually, and has untidy small
ascending/spreading spikelets. The others have fatter spikelets: C. pellita has hairy perigynia in one or two squat spikelets, like the last
digit of a finger. Long rhizomes connect the plants. Carex lacustris and
C. utriculata both have wide leaves, long thick spikelets and form
occasionally large patches in shallow water. Carex lacustris, in
particular, is often sterile, so you have to search around to find a
fertile plant. It has shiny solid-looking perigynia, whereas C. utriculata has more weak, mini-balloon-like perigynia. Finally,
C. retrorsa, which has spreading-to-ascending spikelets. Its perigynia are
smaller than C. tuckermanii (see Group 4), more backwards-pointing, and
“untidy.” I’d say that C. tuckermanii likes the edges of swamp pools,
whereas C. retrorsa is more likely to be found along ditches, wet
meadows, etc., but that might just be me.
Provincially rare ones:
torta – this species is in the aquatilis/stricta group. Like stricta, it
has the leaf at the base of the lowest spikelet shorter than the
inflorescence, but its perigynia are green and smooth.
ones: (these ones are all in the second group, the ones with roundish
atherodes – can grow in fairly deep water, and can form large clones. It
is very similar to Carex lacustris, but its perigynia are even larger,
and its leaves and leaf sheaths are slightly hairy.
buxbaumii – very pretty. It has stubby little spikelets, like Carex
pellita, but usually they’re quite closely packed together, towards the
end of the stem. And they have dark scales that contrast nicely with the
lasiocarpa – like Carex pellita, but the leaves are really thin.
lurida – this species belongs in between Group 1 and Group 2, in that
its spikelets are pretty erect, but sometimes are spreading, or almost
hanging. Like the Group 2 sedges, it has awns on its scales, so looks
spiky. To conclusively separate it from Carex retrorsa, Carex comosa et
al., look at the achenes – they’re “rough-papillose” in C. lurida,
smooth in the others.
vesicaria – this is the slightly-smaller, clumped version of its big
rhizomatous cousin (C. utriculata).
Group 2: Sedges of wet places (normally marshes) with hanging
Much easier than Group 1. There are three main
sedges that fall into this category: C. pseudo-cyperus with its often
backward pointing perigynia and straight teeth on the beaks of the
perigynia; C. comosa which looks similar but has huge spreading teeth on
the beaks (feels like velcro – you can stick spikelets together); and C. hystericina which has shorter, droopier spikelets without cool teeth
(perigynia also rounder, not backward-pointing). It’s really common. The
final sedge put in this group differs from the others in that its droopy
spikelets look spiky not because they have pointed beaks to the
perigynia, but because they have pointed tips (“awns”) to the scales
(thus it’s the scales, not the perigynia, that are spiky). It’s C. crinita.
ones: there are also two similar looking species that are closest to
Group 2, although maybe they should be in their own group. Both have
short inflorescences that droop on thin stalks in a very elegant way,
and are found in bogs and fens.
- Carex limosa – fen species. Large brown scales cover the perigynia, and
- Carex magellanica – bog species, often under conifers. Scales do not
cover the perigynia, and they have awns (often called Carex paupercula).
Group 3: Sedges of forests with thin drooping spikelets.
Very little habitat overlap with Group 2, and these
guys have thinner unspiky spikelets. Carex gracillima, which is common
in wet meadows, edges, etc., has blunt-tipped perigynia, whereas C. arctata has beaks and is more confined to shaded forest habitats.
castanea – this species is related to those of Group 3, but its
spikelets are fatter, so it looks more like Carex limosa or Carex
formosa – ah, the “Handsome Sedge.” And very handsome it is. In moist
meadows, forests, etc., where if favours calcium rich soils, this
species looks like a sleeker, glossier version of Carex arctata, with
slightly wider inflorescences.
prasina – this species looks a lot like Carex arctata, but has a very
different habitat and habit. Instead of growing in woodlands, it grows
along shaded streams, in seepage areas, etc., where it forms large
clumps of tall leaves of a very particular shade of bluey green. Once
you learn to recognize it, the leaves are enough for an ID.
sprengelii – a real weirdo of hardwood forests. The achenes have a round
little body, then a super long thin beak. The spikelets droop, on long
thin stalks, but are wider, like Carex castanea.
Group 4: Sedges with honking-huge inflated perigynia.
There are two species with mace-like inflorescences
– C. grayi which actually does have a tight spherical mace-like
inflorescence, the kind that leprechaun knights might clobber each other
with, and C. intumescens which looks like an incomplete C. grayi. It is
smaller, and its inflorescence is less complete, less spherical. It’s
also much more common. Then there’s C. lupulina, which is like the
above, but with the perigynia stacked into a cylinder, pointing upwards,
instead of a ball. C. tuckermanii could be confused with C. lupulina
(cylindric spikelets) but the spikelets are rather droopy (see the
comments in Group 1).
Group 5: Spikyish hard-to-describe sedges where the spikelets
mostly wrap around the main stem instead of having a stalk, and the
perigynia are flat (or flattish). Now we’re approaching the heart of
sedge-dom. I’m going to split this group into sub-groups.
5a: Relatively unspiky
spiky sedges, with really flat perigynia. The perigynia tend to be
arranged more neatly and tightly packed against each other, so the
effect is of less spikiness. These are the Ovales sedges, and basically
you have to key them out, carefully, to be sure of any identifications.
We have three groups of common ones: Carex tenera with spikelets that
are quite separated from each other (not overlapping), round, and is
really thin-leaved; Carex tribuloides that grows in wet areas and has
larger more pointy spikelets; and Carex bebbii/C. cristatella which
have tidy round spikelets densely packed onto the tip of the stem. In C. cristatella, there are many stems without inflorescences (completely
vegetative), and there’s a loose leaf sheath where the leaves leave the
stem, that flares out at the top (the sheaths have winged margins that
merge with the edges and midvein of the leaf). Carex bebbii lacks these
ones: there are loads of Ovales sedges, and they are tricky. The
comments below are just a guide – you’ll need to collect these to
crawfordii – small, with really pointy spiklets crowded together at the
end of the stem. More crowded then C. scoparia and C. tribuloides (the
other pointy-spikelet species). Likes dry habits.
merritt-fernaldii – big, tall plant, with big round spikelets of big
round flat winged perigynia. Kinda like Carex molesta, except that it
grows on acid sandy area.
molesta – big, tall plant, with big round spikelets of big round flat
winged perigynia. Kinda like Carex merritt-fernaldii, expect that it
grows in calcareous fields, etc.
projecta – shares the sheath and vegetative shoot characters with C. cristatella (as does
C. tribuloides). It is, in many ways, intermediate
between those two (perigynia not as round or tightly clustered as C. cristatella, and not as pointy and loosely scattered at
Its wide leaves differentiate it from C. tenera, C. normalis, etc.
scoparia – longish point perigynia, usually in sandy acidic habitats.
sychnocephala – this is a freaky little dude, with super narrow
perigynia, in a dense head, and a long bract (i.e. “leaf”) at the base
of the inflorescence.
5b: Spiky spiky sedges with spaced out spikelets (not overlapping; scattered like pearls on a necklace, well,
more like stars on a necklace...). First, there’s C. interior, which
grows in shaded wet often coniferous places. Then there’s the two
hardwood forest ones – C. rosea and C. radiata. They look very similar
(little rose-like spikelets strung along the stem), with C. radiata
being a smaller more delicate version of C. rosea.
echinata – a larger version of Carex interior.
5c: Spiky spiky sedges with overlapping spikelets. Arg. This group is annoying. I’ll start with the two rich
forest species that have the spikelets arranged into a very tight
“head,” making the whole think look like a giant pin. They are C. cephalophora and
C. cephaloidea. Easy to remember because “ceph” means
head, as in encephalitis, or cephalopod. Carex cephaloidea is a larger
version of C. cephalophora; Carex cephalophora also usually has little
bristly bracts (“leaves”) sticking out of the inflorescence, which C. cephaloidea usually lacks. And then there’s
C. sparganioides, which
looks like C. rosea (5b) on steroids (it’s big!), except that the
spikelets start to overlap each other, especially towards the tip of the
inflorescence. It likes moistish places, path edges, etc. Carex spicata,
the only non-native sedge that we’ll discuss here, is locally common in
old moist fields, etc. It has bigger perigynia, in rose-like spikelets,
and is reddish or purplish at the base. Then C. vulpinoidea,
C. stipata, C. laevivaginata, and C. alopecoidea both have larger, more
branched, inflorescences. Carex stipata/ laevivaginata/ alopecoidea
(you’ll have to use a key to tell them apart) have stout easily
compressed stems. You can crush them, like triangular gnats, between
your fingers! Carex vulpinoidea, on the other hand, has a tough wiry
stem. It’s dirt common, in ditches, wet meadows, etc. Then there’s Carex
diandra, which I didn’t know what to do with. It looks like the above
species, but grows in dense clumps of thin stems, usually in standing
water of marshes, and has smaller less-branched inflorescences (and
smaller perigynia than the “ceph” ones).
muhlenbergii – closely related to Carex spicata, this is a native
species, with denser heads and broader perigynia, and no red or purple
prairea – this species is close to Carex diandra, but less “spiky” if
that means anything, and with copper tinting to the leaf sheaths and a
more spaced-out inflorescence. It is found in fens.
Group 6: Sedgy-sedges. These are the sedges you think of when
you hear sedge. They are impossible to describe, other than that they’re
not spiky, they have generally rounded or barrel-shaped perigynia. They
grow in meadows or forests, not in marshes or really wet areas. The
perigynia are in clear spikelets that are usually stalked (rather than
wrapped around the stem as in Group 5).
6a: The messy sedges.
We might as well get them
over with. The Laxiflorae and friends – second only to Ovales for
evilness. They have slightly lopsided perigynia in untidy stalked
spikelets. Grow in forests and moist edges. Carex laxiculmis and
digitalis both have really triangular perigynia, and their lower
spikelets are on long droopy thin stalks. Carex digitalis, which grows
in oak uplands, also has male flowers (little scales) at the base of the spikelets.
Carex laxiflora and Carex leptonervia theoretically don’t
have droopy lower spikelets. In C. laxiflora, the perigynia are spaced
out in the spikelet, such that they hardly overlap. And Carex
leptonervia has one strong vein on each face of the perigynia, rather
than a bunch of strong veins (that’s a simplified version – you need to
collect these if you want to be sure). Then there’s Carex blanda – it
usually has slightly broader leaves, and densely packed spikelets that
are really close to each other, so they are forced to diverge from the
end of the stem at a weird angle.
Provincially rare ones:
gracilescens – blooms super early, and looks like the other Laxiflorae,
except that the bases are reddish or purplish. It has closely-packed
perigynia. I’ve only ever seen this once, and I thought it was a
completely different species (C. tetanica – related to Carex woodii), so
take that as you will.
6b: Laxiflorae and
friends with really broad leaves.
These guys are pretty
distinct. They grow in uplands and have wide ribbon-like leaves. Carex
plantaginea has red bases to the plant, and a red-and-green barber pole
for a fertile stalk. Very pretty. Carex platyphylla has whitey-green
leaves, brown bases, and blooms early. I can’t seem to find Carex
albursina, even though it should be common. It looks sort of mid-way
between Carex platyphylla and Carex blanda (which can get broadish
leaves). The definitive feature is that the scales on the perigynia are
blunt tipped instead of having the awn extend into a little pointy
6c: Things that look like Laxiflorae, but aren’t, because their perigynia are more regular and
barrel-shaped with nice strong fine veins.
First there’s Carex grisea, which is a weak-stemmed
sprawling plant of floodplains and other moist areas. And then a
slightly smaller, slightly more-sparsely-flowered version of forests,
Carex hitchcockiana. People working along the talus forest of the
escarpment should look, also, for the very rare C. oligocarpa, which is
a smaller version of C. hitchcockiana, but has red bases instead of
Provincially rare ones:
conoidea – usually on acidic soil, on lake edges, wet meadows, etc. It
has more perigynia, and they’re smaller, than Carex grisea.
6d: Things that look slightly less
like Laxiflorae, but could still get confused.
Carex woodii grows in big patches of thin light
leaves in rich forests; you have to really look to find a fertile one.
The spikelets are sparsely flowered, and the plants have strong rhizomes
(unlike the previous species in Group 6). Carex hirtifolia, as its name
suggests, has hairy leaves. Not has hairy as the wood-rushes (Luzula),
but still hairy. It’s also a woodland species. Then there’s two wet
meadow species. Carex granularis is very common, and has tighter, tidier
spikelets than the Laxiflorae do. And Carex aurea is a small sedge with
really plump sparse perigynia that almost look juicy (they actually have
more of a nutty flavour...).
vaginata – this species is related to C. woodii (has the same
few-flowered spikelets on thin stalks), but grows in calcareous swamps.
pallescens – this species, with chubby little perigynia in neat
cylindric spikelets, is the only member of its group covered here. It
probably looks most like Carex granularis, but its spikelets are shorter
and fatter, among other things.
Group 7: Dryland sedges with red bases and small stalkless
spikelets at the top of the stems.
Carex pensylvanica is probably the most common dry
woodland sedge we have, often forming large patches of often sterile
plants. It’s got long strong rhizomes. Then there are its two
non-rhizomatous look-alikes: the smaller Carex peckii with its thin stem
overtopping the narrow leaves, and the broader-leaved chunkier C. communis. Also closely related to these guys are a group of very cool
little sedges that have all or most of their spikelets nestled down at
the base of the leaves where they are almost impossible to see. You have
to get down on your hands and knees to realize that it’s not just a
patch of leaves. Two species, closely related, distinguished mainly by
the length of the beak of the perigynia: Carex umbellata and C. tonsa
(which itself has two varieties).
Group 8: Sedges with really thin leaves and really small spikelets with very few perigynia that are generally odd-looking.
Carex eburnea is a very distinctive sedge of dry
areas, coniferous areas, cliff-edges, etc. Very thin leaves in dense
patches. Small black perigynia in teeny spikelets. Carex leptalea is
hard to describe, but unique. It has a nice terminal spikelet with
perigynia that look like small grains of rice. It, and the next two
species, grows in moist areas, often shady, often boggy. I like to call
Carex trisperma the “trapeze sedge,” since there are normally three
spikelets spaced out at the end of the stem, and the last two hang out
like trapeze-ers. The first spikelet has a long thin leaf-like bract
that accentuates the trapeze look. There are two varieties – if you find
a very thin-leaved version of Carex trisperma in a sphagnum bog, collect
it! It is probably C. trisperma var. billingsii, which may soon be
recognized as a distinct species. Carex disperma grows in similar
habitats, often shaded, but has fat round perigynia in pairs. Very cute.
Group 9: Misc. sedges that didn’t fit elsewhere.
Carex flava: wet meadows and fen edges, etc. Spiky
yellow stalkless perigynia.
Carex pedunculata: very common very overlooked
sedge of woodlands. It blooms early (May), so most people miss it. But,
blessedly, it is easily recognized even when sterile. The bluey-green
leaves are ribbon-like, untapering, about 1/2cm across. And they always
die back at the tips. So look for untapering leaves with dead tips.
Carex deweyana: also fairly common in woodlands.
This is a scruffy flimsy silvery-looked sedge (the spikelets look
silvery). The stalk droops, like it’s had a hard day.
Carex bromoides: related to C. deweyana, but with
very different habitats. This species forms big tussocks in swampy
pools. Can be recognized pretty much on habit alone (tussocks of thin
leaves in a swamp).
Carex canescens: this species likes boggy areas. It
has match-head sized spikelets of smooth perigynia scattered along the
end of the stem, and a strong bluey cast to the leaves.
brunnescens – this is the smaller cousin of Carex canescens. It has few
perigynia per spikelet, lacks the blue-green cast, and grows in a
variety of non-boggy habitats (C. canescens is more restricted).
chordorrhiza – looks like nothing else – if you’re lucking enough to
trip over the long trailing stems in a cool bog somewhere, then you’ve
found this rare species. It has a messy cluster of perigynia at the end
of the stem, but is easily recognized vegetatively.
cryptolepis – very close to Carex flava, this species is a little
smaller, and has yellow-green scales on the perigynia, instead of brown
viridula – while also related to Carex flava, this species is more
distinct – it is small, green, and spiky. Rather cute, really. Look for
it in gravel pits, and look for the sterile hybrid between it and Carex
flava (called Carex Xsubviridula) wherever both parents occur).
siccata – a species of dry fields, tallgrass remnants, etc. The
spikelets are messy, with big scales, and clustered at the top of the
pauciflora – this is another weirdo – very small, with long narrow
perigynia stuck to the end of the stem like some haphazard punk haircut.
Or a really bad comb. Confined to boggy habitats.
And that’s that. The biggest hurdle is getting used
to the names, and associating the names with the plants... The
organisms, alive, in their habitats, are much more distinctive then
either my rambling descriptions, or the squished versions that you can
find in herbaria. Of course, this is not an exhaustive list of the
sedges of our area – only the more common ones, so if something seems
different, it probably is! As you get familiar with the common species,
you’ll find that you’re able to start “filling in” the rarer ones;
you’ll have a context for them that you didn’t have before.