Palicourea rigida

Names and Synonyms

Scientific Names

Accepted name

Synonyms

• Psychotria rigida var. intermedia
• Palicourea rigida f. brevistyla
• Palicourea rigida f. longistyla
• Palicourea rigida var. stenophylla
• Palicourea aurata
• Psychotria byrsophylla
• Psychotria rigida var. aurata
• Uragoga rigida
• Psychotria rigida
• Psychotria rigida var. hirtella
• Palicourea rigida subsp. hirtella
• Psychotria rigida var. strepens
• Psychotria rigida var. oligoneura
• Palicourea rigida var. hirtibacca
• Palicourea rigida var. amazonica
• Palicourea rigida f. microphylla
• Palicourea rigida f. angustior
• Palicourea rigida var. strepens
• Palicourea rigida var. aurata
• Palicourea strepens
• Palicourea sonans
• Palicourea diuretica
• Palicourea rigida var. paraguariensis

Sources: Wikidata, Catalogue of Life

Taxonomical Classification

This plant belongs to the kingdom Plantae and the phylum Streptophyta, falling under the class Equisetopsida and subclass Magnoliidae. Within the order Gentianaales, it is classified under the family Rubiaceae. It is further identified by the genus Palicourea, which distinguishes this specific medicinal species.

Sources: The World Checklist of Vascular Plants (WCVP)

Distribution

This plant is primarily distributed across several regions in Northern South America. Specifically, it can be found growing within the territories of French Guiana, Guyana, and Suriname. Its presence also extends into the country of Venezuela. Beyond the northern reaches, the species is located in Western South America. This distribution pattern confirms that the plant inhabits parts of both the northern and western continental regions.

Sources: The World Checklist of Vascular Plants (WCVP)

Botanical Identification

Ecology

The ecology of Palicourea rigida is characterized by its broad adaptability to diverse and often nutrient-poor landscapes, spanning a vast altitudinal gradient from sea level (0 m AMSL) to high-altitude environments reaching up to 3550 m AMSL. This species is highly versatile in its habitat selection, thriving in a variety of distinct ecosystems including Campinarana, Campo Rupestre, and Carrasco. It is frequently found within the Cerrado (latu sensu) and the Amazônia Savanna, demonstrating a strong affinity for open or transitional vegetation types. Additionally, its ecological niche extends to specialized environments such as vegetation growing over rocky outcrops (Vegetação Sobre Afloramentos Rochosos), highlighting its ability to colonize rugged and potentially challenging terrains across different elevations.

Elevational range max:

3550 m AMSL

Elevational range min:

0 m AMSL

Habitat :

Campinarana, Campo Rupestre, Carrasco, Cerrado (lato sensu), Savana Amazônica, Vegetação Sobre Afloramentos Rochosos

Life history

The life history of Palicourtea rigida is characterized by its status as a perennial organism, allowing it to persist in its environment through multiple growing seasons. In terms of its structural growth strategy, the plant exhibits a phanerophyte life form, maintaining its buds well above the ground level, while also displaying characteristics consistent with a chamaephyte, where the buds are situated close to the soil surface.

Life form :

chamaephyte

Life form :

phanerophyte

Lifecycle :

perennial

Morphology

The morphology of Palicourtea rigida is characterized by its growth form as a woody shrub or subshrub, reaching a maximum plant height of approximately 8 meters. It is a terrestrial species, functioning as an independent organism rather than a parasite or an epiphyte, as it lacks obligatory, facultative, or hemi-epiphytic tendencies. While it possesses a self-supporting structure, it does not exhibit the climbing habits of a liana or vine, maintaining its stature through its woody stems. Its habitat is strictly non-aquatic, categorized as terrestrial rather than semiaquatic or aquatic.

Aquatic :

terrestrial

Climber :

self-supporting

Epiphyte :

terrestrial

Growth form :

shrub

Growth form :

subshrub

Parasite :

independent

Plant height max:

8 m

Woodiness :

woody

Physiology

The physiology of Palicourea rigida is primarily defined by its carbon assimilation strategy, utilizing the C3 photosynthetic pathway. As a C3 plant, the initial fixation of atmospheric carbon dioxide occurs through the enzyme Rubisco, which incorporates $\text{CO}_2$ directly into a three-carbon molecule during the Calvin cycle. This metabolic process implies that the plant performs all stages of photosynthesis—including light-dependent reactions and the light-independent Calvin cycle—within the mesophyll cells. Because it lacks the specialized Kranz anatomy characteristic of C4 plants or the nocturnal acid storage mechanisms found in CAM species, its physiological efficiency is highly dependent on maintaining adequate stomatal conductance to facilitate gas exchange while managing transpiration rates. Consequently, the plant's metabolic rate and water-use efficiency are closely tied to environmental factors such as light intensity, temperature, and moisture availability, which dictate the equilibrium between photosynthetic gain and evaporative loss.

Photosynthetic pathway :

C3

Sources: Global Inventory of Floras and Traits (GIFT)

Plant Parts

Palicourea rigida has 1 reported plant parts identified across 1 scientific publications and several other databases that are studied for medicinal purposes. The most consistently reported plant part include leaf.

Leaf

1. Journal of fungi (Basel, Switzerland)

Chemicals

Palicourea rigida has 1 reported phytochemicals identified across 1 scientific publications and several other databases. The most consistently reported chemicals include Flavonoid.

Flavonoid

1. Journal of fungi (Basel, Switzerland)