Rorippa gambelii

Family:
Brassicaceae
Common Names:
Gambel's Watercress
Author:
(S. Wats.) Rollins & Al-Shehbaz
Synonyms:
Growth Habit:
Forb/herb
CPC Number:
44446
Profile Contributors:
Dieter Wilken
Sponsorship:
Fully Sponsored

Reference Links

ITIS - Tropicos - USDA Plants - Fish & WildLife

Participating Institutions

The following Participating Institutions are custodians for this species in the CPC National Collection:
Rancho Santa Ana Botanic Garden
Santa Barbara Botanic Garden


The conservation of Rorippa gambelii is fully sponsored.
Dieter Wilken contributed to this Plant Profile.

Description

Once found from San Luis Obispo County south to San Bernardino County, California, and in central Mexico, Gambels watercress today is known from only three localities in the United States, and its numbers have dwindled to perhaps less than 300 individuals. Known from about 8 occurrences in the United States at the time it was listed in 1993, the number of extant populations has dwindled to only three in southern San Luis Obispo County and western Santa Barbara County (Anonymous 2008a; Parikh et al. 1998). At one of these localities, it co-occurs with marsh sandwort (Arenaria paludicola), another endangered species. The last and only report made for San Bernardino County was in 1935 at Urbita Hot Springs, currently the site of a mall next to the Orange Show Fairgrounds in San Bernardino. An early report from the mountains of San Diego County has not been confirmed (Anonymous 2008b). Although reported from Mexico, its status there is unknown (Wickenheiser, L.P. 1989). Gambels watercress (Rorippa gambelii, Cardamine gambelii in literature) is probably best treated as a species of Nasturtium (Al-Shehbaz and Price 1998).

Gambels water cress is an aquatic, herbaceous perennial, producing floating and emergent stems (Abrams and Ferris 1944; Mason 1957; Rollins 1993; Al-Shehbaz and Price, 1998). Vegetative shoots often sprawl over associated vegetation and have been reported to reach up to 1 meter in length, bearing pinnately compound leaves. Vegetative shoots can spread and produce new plants adventitiously. The flowering shoots produce terminal clusters of white flowers. Flowers are about 1 cm wide at anthesis, and bear the 4 white petals and 6 stamens typical of a mustard. Each fruit can produce up to 20 seeds, which are yellowish- to reddish brown in color. Flowering ranges from April through July. Plants of Gambels watercress have been confused with the introduced watercress (Rorippa nasturtium-aquaticum = Nasturtium officinale). These two species are also known to hybridize at one remaining occurrence, making identification more difficult, and also resulting in a potential threat from the apparently more competitive hybrid.

Distribution & Occurrence

Pollinators

Protection

Global Rank:
G1
11/29/2005
Guide to Global Ranks
Federal Status:
LE
08/04/1993
Guide to Federal Status
Recovery Plan:
Yes

State / Area Protection

State/Area Rank Status
California 0 S1.1

Conservation, Ecology & Research

References