Jepson eFlora: Taxon page
Vascular Plants of California
Key to families | Table of families and genera
Previous taxon Index to accepted names and synonyms:
| A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
Next taxon


Potamogeton richardsonii
RICHARDSON'S PONDWEED


Higher Taxonomy
Family: PotamogetonaceaeView DescriptionDichotomous Key
Common Name: PONDWEED FAMILY
Habit: Annual, perennial herb, aquatic, (generally fresh to alkaline), glabrous, from rhizomes, tubers, or winter buds. Stem: erect, simple to branched, cylindric to compressed, rooting at lower nodes; nodal glands present or not. Leaf: simple, cauline, alternate or in subopposite pairs; submersed thread-like to round, sessile or petioled; floating present or not, elliptic to ovate, petioled, leathery; sheath open, continuous with petiole or +- free from blade base, generally stipuled, stipules fused and ligule-like or not. Inflorescence: spike, cylindric to spheric, axillary or terminal, generally emergent, peduncled; bracts 0. Flower: inconspicuous, bisexual; perianth parts [0]4, clawed, +- green, limb generally adaxially concave; stamens [2]4, each fused to base of perianth part [or not], filament generally 0 [short, wide], anthers open to outside; pistils [1]4, ovary 1-chambered, ovule 1, attached to chamber base, style 0 or short. Fruit: drupe, generally obovate, sessile. Seed: 1.
Genera In Family: 3 genera, +- 95 species: worldwide. Note: Recently treated elsewhere to include Zannichelliaceae. Ruppia moved to Ruppiaceae.
eFlora Treatment Author: C. Barre Hellquist, Robert F. Thorne & Robert R. Haynes
Scientific Editor: Thomas J. Rosatti.
Genus: PotamogetonView DescriptionDichotomous Key


Common Name: PONDWEED
Habit: Annual, perennial herb, rhizomed or not, tubers 0, winter buds generally 0. Stem: simple or branched, cylindric to compressed; nodal glands present or 0. Leaf: submersed, also floating or not, generally flat, generally green, entire to finely serrate; submersed sessile or not, linear to round, tip rounded to acuminate, veins 1--35; floating 0 or generally petioled, elliptic to ovate, leathery; stipules of submersed leaves free from blade base or fused to it < 1/2 stipule length. Inflorescence: generally floating to emergent; peduncle stiff. Fruit: generally beaked, abaxially with 0 or 1 central keel, 0 or 2 lateral, sometimes lower keels, sides concave to convex.
Species In Genus: +- 88 species: generally temperate northern hemisphere. Etymology: (Greek: river neighbor, from aquatic habitat) Note: Other taxa in TJM (1993) moved to Stuckenia.
Unabridged Reference: Haynes 1974 Rhodora 76:564--649; Haynes 1985 Sida 11:173--188; Wiegleb 1988 Fedde Rep Sp Nov Regni Veg 99:249--266; Wiegleb & Kaplan 1998, Folia Geobot 33: 241--316.
Potamogeton richardsonii (A. Benn.) Rydb.
NATIVE
Habit: Perennial herb, rhizome matted. Stem: < 70 cm, branches few, generally straight, cylindric. Leaf: submersed, sessile, 1--12 cm, generally 10--20 mm wide, linear- to lance-ovate, margin crinkly near tip, base +- cordate, clasping, tip acute to rounded, flat, not hood-like, not splitting when dry, veins 3--35; stipules < 2 cm, free, persistent as fibers. Inflorescence: < 4 cm, +- < peduncle. Fruit: 2--4 mm, keels 0(1), sides concave to convex. Chromosomes: 2n=52.
Ecology: Uncommon. Shallow to deep water, ponds, lakes, lagoons, streams; Elevation: < 2800 m. Bioregional Distribution: NCo, KR, CaRH, c SN, n SNH, MP; Distribution Outside California: to Alaska, Colorado, eastern North America. Flowering Time: Jul--Aug
Jepson eFlora Author: C. Barre Hellquist, Robert F. Thorne & Robert R. Haynes
Jepson Online Interchange

Previous taxon: Potamogeton pusillus
Next taxon: Potamogeton robbinsii

Name Search

Botanical illustration including Potamogeton richardsonii

botanical illustration including Potamogeton richardsonii

Contact/Feedback

Citation for this treatment: C. Barre Hellquist, Robert F. Thorne & Robert R. Haynes 2012, Potamogeton richardsonii, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=39618, accessed on November 19, 2019.

Citation for the whole project: Jepson Flora Project (eds.) 2019, Jepson eFlora, http://ucjeps.berkeley.edu/eflora/, accessed on November 19, 2019.

No expert verified images found for Potamogeton richardsonii.



Geographic subdivisions for Potamogeton richardsonii:
NCo, KR, CaRH, c SN, n SNH, MP
MAP CONTROLS
1. You can change the display of the base map and layers by clicking on the layer control box in the upper right-hand corner.
2. California county polygons can be turned off and on in the layer control box.
3. Filling of Jepson subdivision polygons can be turned off and on in the layer control box.
4. Moving the cursor over any numbered cluster will show the range boundary of the included specimens (with a blue polygon).
5. Marker clustering can be turned off by clicking this link:      Marker Clustering OFF
WARNING: Turning this off might cause maps with large numbers of specimens to load slowly.
map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).





 

View elevation by latitude chart


Data provided by the participants of the  Consortium of California Herbaria.
MAP LEGEND
View all CCH records
All markers link to CCH specimen records. The original determination is shown in the popup window.
Blue markers indicate specimens that map to one of the expected Jepson geographic subdivisions (see left map). Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.
READ ABOUT YELLOW FLAGS


CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa, if there are more than 1 infraspecific taxon in CA.
Blue line denotes eFlora flowering time.