Rumex hypogaeus T.M.Schust. & Reveal

First published in Taxon 64: 1203 (2015)
This species is accepted
The native range of this species is S. Africa. It is an annual and grows primarily in the subtropical biome.

Descriptions

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation
Predicted extinction risk: not threatened. Confidence: confident
[AERP]

Polygonaceae, R. A. Graham. Flora of Tropical East Africa. 1958

Morphology General Habit
An erect or diffuse, much branched, green herb, glabrous throughout.
Morphology Stem
Stem furrowed.
Morphology Leaves Ocrea
Ocreae 5 mm. long, membranous, brown, readily tearing and falling away.
Morphology Leaves
Leaves long-petiolate, ovate, with a rounded or obtuse apex, basally rounded, truncate or cordate, shortly decurrent to the petiole; when mature with rounded basal lobes containing a broad basal sinus.
Morphology Reproductive morphology Inflorescences
Inflorescence rather laxly racemose, the flowers borne in axillary and sometimes shortly pedunculate clusters (or terminally as a spiciform raceme if the upper leaves are absent).
Morphology Reproductive morphology Flowers
Male tepals green, in two subequal series, ovate-elliptic, 2 mm. long, scarcely exceeding 1 mm. in width, all with brown midrib and veins. Anthers ovate, brownish-orange; filaments filiform, free. Female flowers sessile, all in axillary clusters. Inner 3 tepals erect, rounded or very broadly ovate, strongly veined with lateral veins bifurcating near the margin, the midrib excurrent as a short, rigid, spiny arista. Outer 3 tepals forming at the tips very sharp, rigid spreading spines, 4–5 mm. long; the faces perforated at maturity with usually 4 large pits.
sex Male
Male tepals green, in two subequal series, ovate-elliptic, 2 mm. long, scarcely exceeding 1 mm. in width, all with brown midrib and veins. Anthers ovate, brownish-orange; filaments filiform, free.
sex Female
Female flowers sessile, all in axillary clusters. Inner 3 tepals erect, rounded or very broadly ovate, strongly veined with lateral veins bifurcating near the margin, the midrib excurrent as a short, rigid, spiny arista. Outer 3 tepals forming at the tips very sharp, rigid spreading spines, 4–5 mm. long; the faces perforated at maturity with usually 4 large pits.
Morphology Reproductive morphology Fruits
Fruiting perianth parallel-sided, very accrescent and hard, 6 mm. long, 12–13 mm. overall broad.
Figures
Fig. 1/1 and 2.
Habitat
By roads and railways; essentially a plant of waste land; 1800–1900 m.
Distribution
K3 K4 introduced into our area, probably from South Africa, where it is reputedly native and known as Cape Spinach. Introduced into New Zealand, Madagascar, Australia (intentionally), and occasionally elsewhere as in Florida, California and Hawaii
[FTEA]

Flora Zambesiaca. Vol. 9, Part 3. Polygonaceae-Myriaceae. Pope GV, Polhill RM, Martins ES. 2006.

Type
Type from South Africa.
Morphology General Habit
An erect or prostrate, much branched herb with a semi-woody rootstock An erect or prostrate, much branched herb with a semi-woody rootstock.
Morphology Stem
Stem green or tinged with red especially towards the base, up to 30 cm or more long, furrowed, glabrous Stem green or tinged with red especially towards the base, up to 30 cm or more long, furrowed, glabrous.
Morphology Leaves
Leaf lamina 3.5–6 × 2–3 cm, oblong-ovate to ovate, rounded or obtuse at the apex, rounded cordate or truncate at the base and ± decurrent on the petiole; petiole 3–10 cm long, channelled Leaf lamina 3.5–6 × 2–3 cm, oblong-ovate to ovate, rounded or obtuse at the apex, rounded cordate or truncate at the base and ± decurrent on the petiole; petiole 3–10 cm long, channelled.
Morphology Leaves Ocrea
Ocrea brown, 5 mm long, membranous, lacerated Ocrea brown, 5 mm long, membranous, lacerated.
Morphology Reproductive morphology Flowers
Male flowers in terminal and axillary pedunculate clusters; perianth segments 2 × 1 mm, ovate-elliptic, green with brown midribs and veins; stamens ± as long as the perianth; filaments filiform; anthers orange-brownish, 0.7–0.8 × 0.3 mm, ellipsoid-cylindric. Female flowers sessile, urceolate, 6-lobed; lobes 2-seriate, the 3 inner lobes 3 × 2.5 mm, erect, rounded or very broadly ovate, strongly veined, the lateral veins bifurcating near the margin, the midrib prominent and produced into a spiny awn at the tip; outer lobes connate, forming a tube c. 4 mm long, indurated in fruit and produced at the tips into sharp rigid spreading spines c. 4–5 mm long, the faces perforated with 4 large pits; ovary 3–3.5 × 2–2.5 mm, triquetrous; styles 3, very short, 0.8 × 0.4 mm, broadly ovate, fringed on the inner side and lacerated above Female flowers sessile, urceolate, 6-lobed; lobes 2-seriate, the 3 inner lobes 3 × 2.5 mm, erect, rounded or very broadly ovate, strongly veined, the lateral veins bifurcating near the margin, the midrib prominent and produced into a spiny awn at the tip; outer lobes connate, forming a tube c. 4 mm long, indurated in fruit and produced at the tips into sharp rigid spreading spines c. 4–5 mm long, the faces perforated with 4 large pits; ovary 3–3.5 × 2–2.5 mm, triquetrous; styles 3, very short, 0.8 × 0.4 mm, broadly ovate, fringed on the inner side and lacerated above. Male flowers in terminal and axillary pedunculate clusters; perianth segments 2 × 1 mm, ovate-elliptic, green with brown midribs and veins; stamens ± as long as the perianth; filaments filiform; anthers orange-brownish, 0.7–0.8 × 0.3 mm, ellipsoid-cylindric.
Morphology Reproductive morphology Fruits
Nut 6 × 12–13 mm (including spines), triquetrous, included within the hardened perianth, very accrescent and with divaricate rigid spines Nut 6 × 12–13 mm (including spines), triquetrous, included within the hardened perianth, very accrescent and with divaricate rigid spines.
Morphology Reproductive morphology Seeds
Seeds 3–3.5 × 2.5 mm, triquetrous. Seeds 3–3.5 × 2.5 mm, triquetrous.
Note
S.A. Probably introduced into the Flora Zambesiaca area from South Africa where it is known as ‘Cape Spinach’.
Ecology
On roadsides and as an arable weed in irrigated cereals; 120–1250 m.
Distribution
Mozambique ZIM C, ZIM E, MOZ M Zimbabwe Native to Namibia and South Africa, introduced to East Africa, Madagascar, Australasia and U.
sex Male
Male flowers in terminal and axillary pedunculate clusters; perianth segments 2 × 1 mm, ovate-elliptic, green with brown midribs and veins; stamens ± as long as the perianth; filaments filiform; anthers orange-brownish, 0.7–0.8 × 0.3 mm, ellipsoid-cylindric.
sex Female
Female flowers sessile, urceolate, 6-lobed; lobes 2-seriate, the 3 inner lobes 3 × 2.5 mm, erect, rounded or very broadly ovate, strongly veined, the lateral veins bifurcating near the margin, the midrib prominent and produced into a spiny awn at the tip; outer lobes connate, forming a tube c. 4 mm long, indurated in fruit and produced at the tips into sharp rigid spreading spines c. 4–5 mm long, the faces perforated with 4 large pits; ovary 3–3.5 × 2–2.5 mm, triquetrous; styles 3, very short, 0.8 × 0.4 mm, broadly ovate, fringed on the inner side and lacerated above.
[FZ]

Sources

  • Angiosperm Extinction Risk Predictions v1

    • Angiosperm Threat Predictions
    • http://creativecommons.org/licenses/by/4.0
  • Flora Zambesiaca

    • Flora Zambesiaca
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • Flora of Tropical East Africa

    • Flora of Tropical East Africa
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • Herbarium Catalogue Specimens

    • 'The Herbarium Catalogue, Royal Botanic Gardens, Kew. Published on the Internet http://www.kew.org/herbcat [accessed on Day Month Year]'. Please enter the date on which you consulted the system.
    • Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/
  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0
  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0