Rhynchospora holoschoenoides (Rich.) Herter

Distribution

Biogeografic region: Amazonia, Guiana Shield, Pacific. Elevation range: 0–200 m a.s.l. Native to Colombia. Colombian departments: Cauca, Chocó, Nariño, Valle del Cauca, Vaupés.

Habit

Herb.

Conservation

IUCN Red List Assessment (2021): LC. National Red List of Colombia (2021): Potential LC.

Cyperaceae, K Hoenselaar, B. Verdcourt & H. Beentje. Hypolytrum, D Simpson. Fuirena, M Muasya. Flora of Tropical East Africa. 2010

Type

Type: French Guiana, Cayenne, Le Blond s.n. (P, holo.)

Morphology General Habit

Perennial, 40–130 cm high, base rounded, covered by fibres formed from the older leaf-bases, set at the end of a short curving scaly stolon, and emitting new thick stolons.

Morphology Culms

Culms trigonous to triquetrous, 1.7–3.7 mm wide, glabrous

Morphology Leaves

Leaf sheath pale green to brownish, 2–12 cm long. Leaves up to 70 cm long. Leaf blade linear, stiff and ascending but curved at the apex, 26–63 cm long, 2.5–7.4 mm wide, apex acuminate, glabrous or sometimes scabrid on the margins, midrib and apex

Morphology Reproductive morphology Inflorescences Bracts

Involucral bract 1. Leaf-like, 3–7 cm long, 1–3.5 mm wide, scabrid

Morphology Reproductive morphology Inflorescences

Inflorescence capitate or simple, primary branches 0–5, 1–15.5 cm long.

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets in dense globose clusters at the end of the primary branches, at least one cluster sessile, lanceolate, (3–)5–7 mm long, 1.2–2 mm wide, ± 5 glumes per spikelet.

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes golden brown, elliptic-ovate, 3.2–5.2 mm long, 1.6–2.6 mm wide, apex acute to acuminate, glabrous Glumes 1 and 2 sterile, 3 subtending a bisexual flower and 4 and 5 male flowers.

Morphology Reproductive morphology Flowers Perianth

Perianth of 6 equal bristles, 2.2–3 mm long

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 3: filaments 4.5–5 mm long.

Morphology Reproductive morphology Flowers Androecium Stamens Anthers

Anthers 1.2–2.5 mm long

Morphology Reproductive morphology Flowers Gynoecium Style

Style unbranched or minutely 2branched

Morphology Reproductive morphology Fruits

Nutlet, brown, obovoid, 2.1–2.5 mm long, 1.2–1.5 mm wide, bordered by thickened rims running into the shoulders, minutely punctuate, crown on top of the nutlet yellowish, lanceolate, 1.3–1.5 mm long

Figures

Fig. 53, p359

Ecology

Permanent swamps and ponds; sea-level up to 1800 m

Conservation

Least Concern (LC) due to its wide distribution and common habitat

Note

" R. holoschoenoides shares the globose shaped spikes with R. rubra subsp. africana, but always has at least some spikes on primary branches. R. rubra always has a capitate inflorescence without any branched spikes.

Distribution

Flora districts: T5 T6 T7 Range: Senegal, Guinea, Ivory Coast, Gabon, Zambia, Botswana, South Africa

Cyperaceae, Miss S. S. Hooper. Flora of West Tropical Africa 3:2. 1972

Morphology General Habit

A generally stout, erect plant often about 1 m. high, but sometimes much dwarfed

Morphology Reproductive morphology Inflorescences

An inflorescence somewhat resembling Scirpus holoschoenus Linn.

Ecology

In marshes, swamps and damp grassland, generally near surface water which may be brackish.

IUCN Red List of Threatened Species https://www.iucnredlist.org/species/68150126/68150133

Conservation

LC - least concern

Bernal, R., Gradstein, S.R. & Celis, M. (eds.). 2015. Catálogo de plantas y líquenes de Colombia. Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Bogotá. http://catalogoplantasdecolombia.unal.edu.co

Distribution

Nativa en Colombia; Alt. 0 - 200 m.; Amazonia, Guayana y Serranía de La Macarena, Pacífico.

Morphology General Habit

Hierba

Conservation

Preocupación Menor

J. Browning, K.D. Gordon-Gray†, M. Lock, H. Beentje, K. Vollesen, K. Bauters, C. Archer, I. Larridon, M. Xanthos, P. Vorster, J. Bruhl, K. Wilson and X. Zhang (2020). Flora Zambesiaca Volume: 14: Cyperaceae. M.Á. García, J.R. Timberlake (Eds). Kew Publish

Type

French Guiana, Cayenne, 1792, LeBlonde 36 (P holotype).

Morphology General Habit

Perennial herb to 110(180) cm tall, glabrous; rhizome horizontal or oblique, to c. 4 cm long, scales imbricate, whitish becoming naked in age

Morphology Leaves

Leaves radical, cauline, latter reduced upwards; sheath entire, mouth broadly U-shaped or lipped; ligule very small or lacking

Morphology Culms

Culm erect, eventually recurving under weight of mature fruits, nodose; internodes trigonous to triquetrous

Morphology Reproductive morphology Inflorescences

Inflorescence variable, usually compound of a terminal contracted globose head (cyme) 15 mm diameter plus several pedicelled heads forming an anthelate cluster, sometimes also branched from lower nodes or reduced to 2 or 1 shortly pedicelled heads terminating a culm

Morphology Reproductive morphology Inflorescences Bracts

Bracts leaf-like, unequal in length

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets numerous per globose head, 3–5 mm long; lower 1–2 florets sterile, 3 bisexual, upper 4–5 male or sterile, glumes c. 5 per spikelet, spirally imbricate

Morphology Reproductive morphology Flowers Perianth

Perianth of 3 + 3 bristles, antrorsely barbed, uniform or of varying lengths, not exceeding length of nutlet plus style base

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 3

Morphology Reproductive morphology Flowers Gynoecium Style

Style entire or minutely bifid, surface scabrid

Morphology Reproductive morphology Fruits

Nutlet elliptic in outline, biconvex 2.5–2.7 (including style base) × 1.1–1.2 mm; finely transversely rugulose with few coarse scabrid outgrowths on shoulders; style base persistent, minutely scabrid, attached to nutlet by small central area only, with thickened rims running to shoulders.

Distribution

Zambia, Zimbabwe, Mozambique. Also in Central and South America, Greater and Lesser Antilles, West Africa (Senegal, Ivory Coast, Gabon), Tanzania, Namibia, South Africa (Eastern Cape, KwaZulu-Natal), Madagascar and the Mascarene Is.

Ecology

Wet sandy areas in grasslands and swamps, stream and riverbanks; 10–1300 m.

Conservation

Widespread; not threatened.

Recognition

Rhynchospora holoschoenoides is distinguished from other species in southern Africa by its development of shortly elongated rhizomes when young clothed with whitish imbricate scales that fall away with ageing. In Zambia there is a species allied to R. corymbosa, namely R. triflora which also displays these scales on the rhizome.