Potamogeton pusillus subsp. tenuissimus L. (Mert. & W.D.J. Koch) Haynes & C.B. Hellquist
small pondweed
Potamogetonaceae (Horned pondweed family)
Introduction to Vascular Plants
small pondweed
Potamogetonaceae (Horned pondweed family)
Introduction to Vascular Plants
Photograph
Map
Distribution of Potamogeton pusillus subsp. tenuissimus
Click here to view the full interactive map and legend
Species Information
General:
Perennial, aquatic herb from fine, tufted roots; stems up to 100 cm long, sparingly branched.
Leaves:
All submersed, linear, the sides parallel, thin, green, 1-15 cm long, 0.3-3 cm wide, unstalked, usually with 3 veins, the tips pointed, the stipules 0.5-1 cm long, delicate, not fibrous, greenish or brownish, the margins fused, the veins obscure and faint, the basal glands at nodes well-developed.
Flowers:
Inflorescence spikelike, the spikes 0.5-1.5 cm long, with 2 to 5 whorls of flowers, the stalks thin; bases of the winter buds soft, smooth.
Fruits:
Achenes, almost rounded, 1.5-2.8 mm long, 1.6-2 mm wide, widest above the middle, the beaks short, stubby, the keels absent.
Notes:
Two subspecies, occasionally treated as separate species (e.g., Douglas et al 1994) can be distinguished in our area.
1. Stipules with fused margins; leaves without translucent bands along the midveins or with the bands up to 2-rows wide on each side of the midveins; marginal veins join the midveins about 2 mm from the leaf tips in a sharp angle....................ssp. pusillus
1. Stipules with overlapping margins; leaves with translucent bands up to 5-rows wide on each side of the midveins; marginal veins join the midveins about 0.5-1 mm from the leaf tips in a blunt (60 degree) angle....................ssp. tenuissimus (Mert. & Koch) Haynes & C.B. Hellquist
Illustration
If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.
Illustration Source: The Illustrated Flora of British Columbia
Ecology
Ecological Framework for Potamogeton pusillus ssp. tenuissimus
The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)
The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)
| Site Information |
Value / Class |
||
|
Avg |
Min |
Max |
|
| Elevation
(metres) |
1117 | 1117 | 1118 |
| Slope
Gradient (%) |
0 | 0 | 0 |
|
Aspect (degrees) |
0 | ||
| Soil
Moisture Regime (SMR) [0 - very xeric; 4 - mesic; 8 - hydric] |
8 | 8 | 8 |
| Modal
Nutrient Regime
Class |
E | ||
| #
of field plots species was recorded in: |
12 | ||
| Modal
BEC Zone Class |
CWH | ||
|
All BEC Zones (# of stations/zone) species was recorded in |
CDF(3), CWH(7), SBPS(2) | ||
|
Source:
Klinkenberg 2013
|
|||
Habitat and Range
Lakes, ponds, sloughs and ditches in the lowland, steppe and montane zones; frequent in BC; circumpolar, N to AK, YT and NT, E to NF and S to ME, MA, PA, NC, FL, MS, LA, TX, NM, AZ and CA; Eurasia, Mexico, Africa.Synonyms
Synonyms and Alternate Names:
Potamogeton berchtoldii Fieber
Potamogeton berchtoldii var. acuminatus Fieber
Potamogeton berchtoldii var. colpophilus (Fern.) Fern.
Potamogeton berchtoldii var. lacunatus (Hagstr.) Fernald
Potamogeton berchtoldii var. mucronatus Fieber
Potamogeton berchtoldii var. polyphyllus (Morong) Fern.
Potamogeton berchtoldii var. tenuissimus (Mert. & Koch) Fern.
Potamogeton pusillus var. mucronatus (Fieber) Graebn.
Potamogeton pusillus var. tenuissimus Mert. & W.D.J. Koch