Psathyrostachys juncea
Russian Wild-Rye
Lateral Spikelet, Florets Spread
Saskatchewan Landing Provincial Park
12-June-2024
Each spikelet is subtended by a pair of glumes
which do not overlap each other at their base. The number of florets in each
spikelet varies from 1 to 3. This spikelet has 3 florets which have been
manually spread apart.
The following items are taken from keys in Flora
of Saskatchewan, Fascicle 4, Grasses of Saskatchewan by Anna L. Leighton and
Vernon L. Harms. Family Poaceae is first divided into tribes, then the
tribes are divided into genera, and the genera divided into species.
However, there are a number of tribes that are very difficult to distinguish
morphologically. These are grouped into a large, artificial tribe I call
"Multitribe". Multitribe is then divided into groups, and each
group is then divided into genera. The answers are in the order you would
normally work through the keys.
| Triticeae: Answers to key questions
leading to this tribe.
| Mature inflorescence, if breaking into units, then the units not as
below; NOT [Mature inflorescence breaking into spikelet units consisting
of a sessile fertile spikelet, a hairy pedicel with or without a sterile
spikelet at tip, and a hairy rachis joint, all arising at the same point
(a node) in specialized panicle branches called rames] |
| Spikelets not as below; sterile florets if present, either located
distal to the fertile floret(s) on the rachilla or paired and attached
at the base of a single fertile floret, not paired with the upper glume
as below; lemma and palea variously textured, enclosing the flower or
not; disarticulation usually above the glumes; NOT [Spikelets usually
dorsally compressed, appearing 1-flowered but containing 1 fertile
floret and 1 sterile floret, the latter attached to the base of fertile
floret opposite the upper glume, resembling the upper glume, and
together with the upper glume enveloping the fertile floret; lower
glumes minute (sometimes absent) to 3/4 as long as upper glumes and
typically wrapping most of the way around the pedicel at base; fertile
floret seed-like with chartaceous-indurate lemma and palea enclosing
flower and fruit; disarticulation below the glumes with rare exceptions] |
| Spikelets 1 to many-flowered, subtended by a pair of glumes (only 1 on
lateral spikelets in Lolium); palea margins enclosed or not; plants of
dry or wet habitats; NOT [Spikelets 1-flowered, lacking glumes; margins
of the palea tightly enclosed by the lemma margins on female or perfect
florets; plants of wetlands, often emergent aquatic] |
| Inflorescence a terminal spike with sessile or subsessile spikelets
attached broadside at nodes on opposite sides of the rachis; NOT
[Inflorescence not as above; if a terminal spike, then the lateral
spikelets attached edgewise to the rachis with inner (upper) glume
wanting (as in Lolium)]
|
|
| Psathyrostachys: Answers to key questions
leading to this genus.
| Spikelets 2 or more per node, occasionally 1 at some nodes; NOT
[Spikelets 1 per node, occasionally 2 at some nodes] |
| Spikelets 2-7 per node with 1-7 (9) florets per spikelet; if spikelets
3 per node, then some spikelets with more than 1 floret; NOT [Spikelets
3 per node with 1 floret per spikelet; florets in central spikelet
always fertile, those in the 2 lateral spikelets sterile and greatly
reduced in plants that disarticulate at rachis nodes but may be fertile
in plants with a continuous rachis] |
| Lemmas unawned or with awns up to 4 mm long; glumes not distinctly
bowed out at base; NOT [Lemmas awned, the awns usually (5) 8-120 mm
long, shorter (to 3 (5) mm) in plants with glumes distinctly bowed out
(as in E. curvatus)] |
| Spikelets sessile, 1-2 (3)-flowered; glumes not overlapping at base;
rachis internodes 2-4 mm long; glumes 3-6 (7) mm long (in ours), ±
equal; disarticulation above the glumes, or at the rachis nodes late in
maturity; NOT [Spikelets sessile or subsessile, usually 3-7
(9)-flowered; if 2-flowered, then glumes overlapping at base concealing
the base of the lowest floret; rachis internodes 4-10 mm long; glumes
(5) 7 mm long or longer, if shorter, then distinctly unequal in length
within a pair; disarticulation above the glumes, not at the rachis
nodes] |
|