Victorin’s gentian COSEWIC assessment and status report: chapter 4

Distribution

Global range

Victorin’s gentian is found only in Canada, in the St. Lawrence estuary (Figure 2). Given its limited range, it is considered endemic to the fluvial section of the estuary (Labrecque and Lavoie, 2002).

Figure 2. Global range of Victorin’s gentian.

1

Canadian range

Victorin’s gentian grows only in the freshwater and slightly brackish intertidal zones of the St. Lawrence River (Figure 3). To date, the plant has been inventoried in 43 localities (Table 1). The southwestern limit is at Deschambault and Lotbinière, and the northeastern limit is at Saint-Roch-des-Aulnaies and Île aux Oies (Brouillet et al., 1996).

Figure 3. Canadian range of Victorin’s gentian (taken from Labrecque and Lavoie, 2002).

Figure 3.  Canadian range of Victorin’s gentian (taken from Labrecque and Lavoie, 2002).

Four localities mentioned in the report provided by the Centre de données sur le patrimoine naturel du Québec (CDPNQ) seem unlikely, questionable or ephemeral. One herbarium specimen from Pont-Rouge, collected by Father Louis-Marie, Brothers Fabius and Adonis, Marcel Raymond and J. Paquin on August 12, 1934 (No. 34605 at Laval University’s Louis-Marie herbarium) is an unlikely locality, because the site is not subject to tidal cycles and has since been extensively botanized by various botanists, including the author in preparing the update status report on Provancher’s fleabane (Erigeron philadephicus var. provancheri). In this specific case, the inaccuracy must be due to a label error. The locality of Sainte-Anne (no collection date) is more plausible because the label reads “freshwater beaches”. In this specific case, it could be Sainte-Anne-de-Beaupré, but no Victorin’s gentian plants were observed in several inventories conducted in this sector, despite the existence of adjacent localities. The localities of Saint-Germain (July 30, 1952) and “North Shore” (1932) are likely ephemeral and are specimens that were uprooted by the ice along the shorelines in upstream localities and redeposited further downstream. The water salinity at Saint-Germain-de-Kamouraska and on the North Shore is too high for the long-term survival of Victorin’s gentian.

Table 1. List of Victorin’s gentian populations in 2002 with quality indices
Location Population Disturbance Quality index1 Latest observation
Deschambault
100-1000
low
A
1996-09-01
Grosse-Île
200-400
none
A
2000-08-10
Sainte-Croix, Pointe Platon
111-1050
moderate
A
1995-09-05
Saint-François, Pointe d'Argentenay
100-1000
none
A
1995-09-14
Saint-Augustin-de-Desmaures
300-500
low
A
2002-08-29
Sainte-Pétronille, Anse chez Porteous
200-500
none
A
2002-08-10
Saint-Vallier, Pointe à Labrecque
200-400
none
A
2002-08-10
Berthier-sur-Mer, Anse de Berthier
55-110
none
B
1995-09-13
Ile aux Grues, Rivière à Anguilles
13-60
none
B
1996-09-04
L'Ange-Gardien, Casgrain Street
51-100
low
C
1996-09-03
L'Ange-Gardien, du Fleuve Street
51-100
low
C
1996-09-03
Saint-Jean-Port-Joli, two sides of wharf
30-120
high and none
C
1997-09-01
Saint-Jean-de-Boischatel
11-59
low
C
1995-08-24
Saint-Antoine-de-Tilly, Les Fonds
11-50
low
D
1995-09-07
Saint-Nicolas, Anse Ross
2-10
low
D
1996-09-03
Sainte-Pétronille
32
high
D
1997-09-02
Beaumont, Anse de Vincennes
11-50
none
D
1995-08-24
Saint-Laurent-d'Orléans
32
low
D
1997-09-02
Pointe-aux-Trembles-Ouest
3-11
low
D
1995-09-19
Lévis, Pointe Martinière
15
low
D
1996-09-04
Saint-Laurent-d'Orléans, Village-des-Anglais
25-100
moderate
D
1995-09-20
Ile aux Grues, wharf
11-50
low
D
1996-09-04
Neuville, Provancher marsh
10-30
low
D
1999-08-04
Berthier-sur-Mer, Road 561
1
none
D
2000-08-11
Montmagny
1
low
D
1977
Saint-Vallier, Anse de Saint-Vallier
-
none
E
1985
Saint-Jean-Port-Joli, Pointe à Menin
-
-
H
1975-07-17
Lotbinière
-
high
H
1986
Île de Bellechasse
-
-
H
1925-08-28
Île aux Deux-Têtes
-
-
H
1925
Île aux Oies, Anse à la Beguine
-
-
H
1970-08-05
Sainte-Croix
-
low
H
1943
Saint-Michel-de-Bellechasse
-
high
H
1961-09-03
Cap Saint-Ignace
-
none
H
1959
Saint-Jean-Port-Joli, Anse de Trois-Saumons
-
none
H
1954
Saint-Roch-des-Aulnaies
-
none
H
1939
Beauport
-
high
X
1943
Cap Rouge
-
high
X
1942
Lévis
-
high
X
1935
L'Islet-sur-Mer, Rocher Panet
-
high
X
1947
Saint-Romuald, Garneau Bridge
-
high
X
1954
Saint-Romuald
-
high
X
1936
Sillery
-
high
X
1971
Total 1,576-5,781       Average        3,679  

1 See Table 2 for the meaning of classes A-D. The quality index X (extirpated) indicates that the habitat and/or Victorin’s gentian are extirpated from this location, despite sampling efforts in recent years. The quality index E (recent) indicates that the observation of the population dates back at least 25 years, but that we do not have information on its demography. The quality index H (historic) indicates that the observation of the population dates back more than 25 years.

Table 2. Definition of quality indices of Victorin’s gentian populations
Quality index Meaning of index
A
Population of over 200 individuals in a habitat that is only slightly or not disturbed by human activity.
B
Population of 101-200 individuals in a habitat that is only slightly or not disturbed by human activity or population of 200 individuals disturbed by filling or pedestrian or vehicle traffic.
C
Population of 50-100 individuals in a habitat that is only slightly or not disturbed by human activity or population of 101-200 individuals disturbed by filling or pedestrian or vehicle traffic.
D
Population of less than 50 individuals in a habitat that is only slightly or not disturbed by human activity or population of 50-100 individuals disturbed by filling operations, human trampling or vehicle traffic.

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