Rumex obtusifolius

L. (1753)

This name is accepted

Kingdom: Viridiplantae Phylum: Magnoliophyta Class/Clade: Eudicot-CoreEudicot Order: Caryophyllales Family: Polygonaceae Genus: Rumex

bitter dock

Description

Key Characters:

Growth Form: Erect perennial herbs.

Stems: Stems 6–12 dm long, striate, glabrous.

Roots: Taprooted.

Leaves: Leaves simple. Alternate. Blades oblong–ovate to oblong–lanceolate, basal leaves usually 25–45 cm long, 9–11 cm wide, cauline leaves 6–30 cm long, 2–11 cm wide. <u>Apex</u> acuminate to obtuse. Apex acuminate to obtuse. <u>Base</u> truncate to subcordate. Base truncate to subcordate. <u>Upper surfaces</u> usually glabrous; <u>lower surfaces</u> usually papillose–pilose along veins, occasionally glabrous. Upper surfaces usually glabrous; lower surfaces usually papillose–pilose along veins, occasionally glabrous. <u>Margins</u> subentire to erose, undulate. Margins subentire to erose, undulate. Petioles usually 2–9 cm long, those of basal leaves up to 25 cm long. <b>Stipules</b> forming sheath or ocrea. Stipules forming sheath or ocrea.

Flowers: Flowers usually 14–24 in clusters, these arranged in racemose, sometimes branched inflorescences. Flowers unisexual (and the plants monoecious), actinomorphic. <b>Tepals</b> 6, outer 3 much smaller than inner ones, green, connate at base into a minute floral tube, inner 3 valves erect, staminate flowers with outer Tepals 0.8–1 mm long, the valves membranous, 1–1.3 mm long; pistillate flowers with outer Tepals 1–1.2 mm long, the valves membranous, 1.5–2 mm long, enlarging to 4–5 mm long and becoming narrowly cordate in fruit, margins with straight or slightly curved teeth, some of which are 1–1.2 mm long, at least 1 of the valves with a tubercle, the tubercles unequal, 0.6–2 mm long. <b>Stamens</b> 6; <u>anthers</u> dithecal, opening by longitudinal slits. Ovary superior, 1-celled; ovule 1; styles 3; stigmas fimbriate, dry.

Fruit: Nuts trigonous; enclosed by the valves; dark brown; 2–2.4 mm long; the surface glossy. Seeds with well-developed; starchy and oily endosperm.

Ploidy: 2n = 20; 40; 60

Habitat: Relatively mesic; disturbed areas and sometimes in areas dominated by native specie.

Elevation Range: 600–1,470 m.

Historical Distribution

Accepted Subtaxa (in Hawai'i) (1)

Uses and Culture

USES

Natural History

Statewide Status

Naturalized

Island Status

Kaua'i Naturalized
O'ahu Naturalized
Hawai'i Naturalized

Dispersal Agents


Pollinators

Specimens

Bibliography

Name Published In: Sp. Pl.: 335 (1753)

Occurrences

SNo. Scientific Name Scientific Name Authorship Locality Habitat Basis of Record Recorded By Record Number Island Source Date
1 Rumex obtusifolius L. Ocean View, HI, USA PRESERVED_SPECIMEN L. Cuddihy & S. Anderson 922 Maui HAPI 11/2/1981
2 Rumex obtusifolius L. Kauai PRESERVED_SPECIMEN Plews, J.H.R. 2105 Kauai BISH 6/16/1926
3 Rumex obtusifolius L. Honopu; about 100 ft before start of trail Along main road. PRESERVED_SPECIMEN Tangalin, N. 629 Kauai BISH 12/8/2005
4 Rumex obtusifolius L. Waialua Town, Waialua District, in weedy pasture in gulch behind town PRESERVED_SPECIMEN Nagata, K.M. 3262 Oahu BISH 6/19/1985
5 Rumex obtusifolius L. Kahuku, on lower end of Charlie Road. Dry, disturbed lowland roadside. PRESERVED_SPECIMEN Heintzman, S. USARMY 369 Oahu BISH 2/23/2015
6 Rumex obtusifolius L. honopu; about 100 ft before start of trail Along main road. PRESERVED_SPECIMEN tangalin, n. et al. collector number: 629 Kauai BISH 12/8/2005
7 Rumex obtusifolius L. kauai yard PRESERVED_SPECIMEN plews, j.h.r. collector number: 2105 Kauai BISH 6/16/1926
8 Rumex obtusifolius L. waialua town, waialua district, in weedy pasture in gulch behind town PRESERVED_SPECIMEN nagata, k.m. bauer, g.; barrera, b. collector number: 3262 Oahu BISH 6/19/1985
9 Rumex obtusifolius L. Ocean View, HI, USA PRESERVED_SPECIMEN L. Cuddihy & S. Anderson 922 Maui HAPI 11/2/1981
10 Rumex obtusifolius L. Kauai PRESERVED_SPECIMEN Plews, J.H.R. 2105 Kauai BISH 6/16/1926
11 Rumex obtusifolius L. Honopu; about 100 ft before start of trail Along main road. PRESERVED_SPECIMEN Tangalin, N. 629 Kauai BISH 12/8/2005
12 Rumex obtusifolius L. Waialua Town, Waialua District, in weedy pasture in gulch behind town PRESERVED_SPECIMEN Nagata, K.M. 3262 Oahu BISH 6/19/1985
13 Rumex obtusifolius L. Kahuku, on lower end of Charlie Road. Dry, disturbed lowland roadside. PRESERVED_SPECIMEN Heintzman, S. USARMY 369 Oahu BISH 2/23/2015
14 Rumex obtusifolius L. honopu; about 100 ft before start of trail Along main road. PRESERVED_SPECIMEN tangalin, n. et al. collector number: 629 Kauai BISH 12/8/2005
15 Rumex obtusifolius L. kauai yard PRESERVED_SPECIMEN plews, j.h.r. collector number: 2105 Kauai BISH 6/16/1926
16 Rumex obtusifolius L. waialua town, waialua district, in weedy pasture in gulch behind town PRESERVED_SPECIMEN nagata, k.m. bauer, g.; barrera, b. collector number: 3262 Oahu BISH 6/19/1985