RCHSC
Growth form
broadleaf
Biological cycle
annual
Habitat
terrestrial
synonym | Plethyrsis glauca Raf. |
synonym | Richardia cubensis A.Rich. |
synonym | Richardia pilosa Ruiz & Pav. |
synonym | Richardia procumbens Sessé & Moc. |
synonym | Richardia scabra var. chacoensis E.L.Cabral & Bacigalupo |
synonym | Richardsonia cubensis A.Rich. |
synonym | Richardsonia pilosa (Ruiz & Pav.) Kunth |
synonym | Richardsonia scabra (L.) A.St.-Hil. |
synonym | Spermacoce hirsuta Willd. |
synonym | Spermacoce hirsuta Willd. ex Roem. & Schult. |
synonym | Spermacoce involucrata Pursh |
Malagasy |
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Global description
Richardia scabra is an annual, herbaceous, prostrate plant, 20 to 60 cm high. Quadrangular stems, branched, colored (red-brown), very hairy. Taproot. Leaves opposite, decussate, entire, 1 to 4 cm long, broad, hairy. White flowers grouped in terminal glomerules (5-25 flowers per inflorescence).The corolla consist of 4 to 6 lobes and a trilocular ovary whose style terminate by a trifid stigma. Reproduction mainly by seed.
Cotyledons
Cotyledons subsessile, with an oval blade, with rounded tip and a stipular flange at the base.
First leaves
The first leaves are simple, opposite, short-stalked, perpendicular to the lamina of cotyledons. The leaf blade is ovate-oblong to oval elliptical, with a wedged apex, base attenuated into a petiole. The midrib is well marked taking a reddish color towards the petiole, veins and margin are strongly scabrous.
General habit
Richardia scabra is a prostrate or erect annual herb, profusely branched from the base, and reaching up to 60 cm in height.
Underground system
The main root is a taproot.
Stem
The stem is thick, with quadrangular section, covered with long dense white hispid hairs, erect or prostrate, reaching up to 60 cm tall, with loose branching.
Leaf
The leaves are simple, opposite, decussate, sub sessile, with ovate to elliptic lanceolate blade, 1.5 to 4.5 cm long and 0.7 to 2.5 cm wide, thick and membranous, base attenuate into a short poorly individualized petiole, wedged and mucronate apex, more or less scabrous and hirsute on both sides, margin ciliated to scabrous; stipular collar between the petioles, 2-4 mm high and 3-4 mm wide, hispid, with 1 to 5 subequal filiform appendages, 3 to 4 mm long with ciliate margin.
Inflorescence
Inflorescence in terminal clusters, 0,8-1,5 cm in diameter, sessile, subtended by the pair of terminal leaves; the last two leaves being shorter and smaller than the previous pair and is arranged perpendicularly.
Flower
Small tubular flowers, 2 to 8 mm long, usually white in color; calyx 2 to 2.5 mm long with 4 to 6 lobes (1 mm), scabrous; corolla with a basal tube surmonted by 4 to 6 acute triangular lobes, 2 to 3 mm, usually white in color. Each flower has 3 to 6 stamens located between the lobes of the corolla; ovary subglobose with 3 loculus, containing 1 ovule per loculus. It is topped by a style ending into a trifid stigma
Fruit
The fruit is a trilocular, ovoid to subglobose capsule, 1.5 to 3.5 mm long and 1 mm in diameter, with a pronounced scabrous appearance. Each compartment contains one seed.
Seed
The seed is oblong to triangular, thick, hollow and has 2 longitudinal lobes. The ventral surface has a wide longitudinal groove. It is 2 to 3 mm long and 1.5 mm wide. The integument is glabrous, greyish-beige, with fine white dots and numerous short, thick spines.
Attributions | Wiktrop |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Attributions | Wiktrop |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Attributions | Wiktrop |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Richardia scabra is very similar to Richardia brasiliensis Gomes. R. scabra is distinguished by its large flowers with triangular lobes 2.5 mm long and 1.5 mm wide and its leaves which are sparsely hairy on the upper surface except towards the margin. The seed is triangular with 1 wide longitudinal groove on the ventral face. R. brasiliensis has small flowers with a white corolla sometimes tinged with pink, lobes 1-1.4 mm long and leaves covered with short hairs on the upper face. The seed is flattened with 2 large longitudinal depressions on the ventral face.
Lareg leaves, elliptic or oblong | stem quadrangular winged | Spermacoce alata | |
tige quadrangular rounded | Green stem, slightlypubescente | Mitracarpus hirtus | |
Brown red stem, hispid | Richardia scabra | ||
Linear leaves | Leaves opposite by 2 | inflorescence in corymb | Oldenlandia corymbosa |
leaves appearing whorl | inflorescence in glomerule | Spermacoce verticillata |
In the seedling stage, Richardia scabra can be confused with Mitracarpus hirtus. Differentiation is easily made by the filiform appendages (tapered teeth) of the stipular collar, which are typically reddish in number (1 to 4) in Richardia scabra and whitish in number (5 to 10) in Mitracarpus hirtus.
Attributions | Wiktrop |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Brazil: Richardia scabra is a ruderal species and a common weed of annual and perennial crops. It is tolerant to a wide range of soil types, but prefers sunny environments.
China: Richardia scabra is a ruderal species from 0 to 200 m altitude. Introduced in China in the 1980s.
Madagascar: Richardia scabra grows on the rich or degraded soils: ferralitic soils, ferruginous soils and alluvial soils, along roadsides and near houses on sunny plots. It is a weed of crops and pastures in the sub-humid areas of the Middle West, Central Highlands and the Middle East. It can be found in cropping systems of pluvial rice, maize and cassava, semi-intensive, with or without addition of organic manure.
Mauritius: species absent.
Nicaragua: R. scabra is a common ruderal species throughout the country from 0 to 1400 m altitude.
Reunion: A recently introduced weed (2015 approximately), present in a few sugarcane plots in Saint Denis and Saint Pierre.
Attributions | Wiktrop |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Origin
Richardia scabra is native to Central and South America.
Worldwide distribution
It is present in many tropical regions (Central America and the Caribbean, South America, South and East of the USA, Southern Africa, Madagascar, India, Southeast Asia, Indonesia). Introduced in China in the 1980s and in Reunion in 2015.
Attributions | Wiktrop |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Attributions | Wiktrop |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Attributions | Wiktrop |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Attributions | |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Herbarium pictures ReCOLNAT: https://explore.recolnat.org/search/botanique/simplequery=Richardia%2520scabra
Attributions | |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Root | Root |
Kingdom | Plantae |
Phylum | Tracheophyta |
Class | Magnoliopsida |
Order | Gentianales |
Family | Rubiaceae |
Genus | Richardia |
Species | Richardia scabra L. |