Ryania speciosa

Ryania speciosa

Ryania (Ryania speciosa Vahl, 1796) is an arboreal species belonging to the Salicaceae family.

Systematics –
From a systematic point of view it belongs to:
Eukaryota domain,
Kingdom Plantae,
Subkingdom Tracheobionta,
Spermatophyta superdivision,
Magnoliophyta division,
Class Magnoliopsida,
Subclass Dilleniidae,
Salicales Order,
Salicaceae family,
Genus Ryania,
Species R. speciosa.
The terms are synonyms:
– Patrisa speciosa (Vahl) Monach.;
– Patrisia chocoensis (Triana & Planch.) Warb.;
– Patrisia chocoensis Triana & Planch.;
– Patrisia speciosa (Vahl) Monach.;
– Ryania patrisii Miq.;
– Tetracocyne angustifolia Turcz..
The following varieties are recognized within this species:
– Ryania speciosa var. bicolor (DC.) Monach.;
– Ryania speciosa var. chocoensis (Triana & Planch.) Monach.;
– Ryania speciosa var. minor Monach.;
– Ryania speciosa var. mutisii Monach.;
– Ryania speciosa var. panamensis Monach.;
– Ryania speciosa var. speciosa;
– Ryania speciosa var. stipularis (Linden & Planch.) Monach.;
– Ryania speciosa var. subuliflora (Sandwith) Monach.;
– Ryania speciosa var. tomentella Sleumer;
– Ryania speciosa var. tomentosa (Miq.) Monach..

Etymology –
The term Ryania was given in honor of Patrick Russell-Ryan, an 18th-century British physician, naturalist and botanist.
The specific speciosa epithet comes from spécies beltà: good-looking, showy, elegant.

Geographic Distribution and Habitat –
Ryania speciosa is a tropical plant native to regions of Central and South America, including countries such as Brazil, Colombia, Venezuela, Peru and Ecuador.
Its natural habitat is that of tropical rainforests or tropical evergreen forest areas. These habitats are characterized by abundant rainfall and warm temperatures throughout the year.
The plant is found at low altitudes, often in the plains or on the slopes of tropical mountains, where it grows on well-drained soils rich in organic substances. This genus of plants prefers moist but not flooded soils.

Description –
Ryania speciosa is a hermaphrodite, evergreen shrub or tree growing to about 15 meters.
The young stems have straw-colored starry trichomes appressed (even with simple trichomes).
The leaves are alternate, distichous, oblong or oblong-elliptic, 6,5 cm long and 3,1 cm broad, with caudate apex, base obtuse (rounded), inequilateral, entire margin, pellucid spots sometimes conspicuous, basal glands absent, pinnate nerves and semi-persistent stipules.
The inflorescences are axillary with 3 or 4 gems, but usually only one open flower at a time, on an about 1 mm long peduncle, few small bracts at the apex of the peduncle; sepals 5, almost free, 20-27 mm long and about 59 mm broad, briefly stellate-tomentose, white or cream in colour; petals absent; stamens numerous, peripheral, filaments 17-20 mm long, fused at the base; the stamens are 30–70, ± perigini; the filaments are reddish to whitish, separate, filiform; upper ovary, silky, style 15-19 mm long, 4 or 5 fidia, stigmas capitate.
The fruit is a globular capsule, of 3 cm of diameter, with persistent style, dry, indehiscent or finally dehiscent by valves, densely covered by minute, starry appressed trichomes and longer, scattered, brown simple trichomes.
The seeds are numerous, 5 mm long and 5 mm wide, with scattered star trichomes and aril dotted with resin at the base.

Cultivation –
Ryania speciosa is a plant which, in order to be cultivated, has particular needs linked to its particular natural habitat.
In fact it is native to the tropical regions of Central and South America and is known for its insecticidal properties. Here are some tips on growing Ryania speciosa:
This plant is therefore suitable for tropical and subtropical climates. It develops best at temperatures between 20°C and 30°C and does not tolerate cold or frost. If growing in an area with cold winters, consider growing the plant in pots and bringing it inside during cool weather.
It requires a lot of direct sunlight.
The plant prefers well-drained soils rich in organic matter and soil with a slightly acidic pH is ideal.
Propagation can be done by sowing seeds or by propagating cuttings.

Customs and Traditions –
Ryania speciosa is a species of plant of the Salicaceae family, native to the tropical regions of Central and South America, and was discovered and classified by Carl Linnaeus, the father of binomial nomenclature, in the 18th century.
This plant is known for its medicinal and poisonous properties, and has traditionally been used by indigenous peoples for medicinal and poisonous purposes.
The species is in fact of considerable importance as the ryanoid insecticides derive from and have the same mode of action of the ryanodine alkaloid, originally extracted from this South American plant, also used as a fish killer.
Its wood, dried and finely ground, is used to defend the pome fruit from Cydia pomonella and for other uses.
The presence of the vegetable alkaloid ryanodine in this plant allows the ryanodine receptors to be deactivated and therefore block muscle contraction.
In fact, ryanodine has a high binding affinity with the ryanodine receptor, a group of calcium channels found mainly in skeletal muscle and in the myocardium.
At nanomolar concentrations, ryanodine blocks the receptors in the semi-open stage, while at micromolar concentrations, it closes them completely. When present in nanomolar concentrations, ryanodine allows the release of calcium from the sarcoplasmic reticulum allowing muscle contraction.

Method of Preparation –
Ryania speciosa is a plant known to contain toxic alkaloids, including ryanodine and rianodol. These substances can be dangerous to humans and other animals if ingested in large quantities. The alkaloids in this plant work by interfering with the calcium channels in muscle cells, leading to excessive calcium release and causing paralysis and death.
Despite its toxicity, some indigenous peoples of South America have used parts of the plant, such as the bark and roots, in traditional medicinal preparations. However, the use of this plant is extremely risky and not recommended due to its poisonous effects.
Among other uses, the oil extracted from the seeds of Ryania speciosa was used in the past for industrial purposes, such as the treatment of wood and the production of paints and insecticides.

Guido Bissanti

Sources
– Acta Plantarum – Flora of the Italian Regions.
– Wikipedia, the free encyclopedia.
– GBIF, the Global Biodiversity Information Facility.
– Useful Tropical Plants Database.
– Conti F., Abbate G., Alessandrini A., Blasi C. (ed.), 2005. An annotated checklist of the Italian vascular flora, Palombi Editore.
– Pignatti S., 1982. Flora of Italy, Edagricole, Bologna.
– Treben M., 2000. Health from the Lord’s Pharmacy, Advice and experiences with medicinal herbs, Ennsthaler Editore.

Photo source:
– https://inaturalist-open-data.s3.amazonaws.com/photos/256098951/original.jpeg
– https://sweetgum.nybg.org/images3/2100/517/02692656.jpg

Attention: The pharmaceutical applications and alimurgical uses are indicated for informational purposes only, they do not in any way represent a medical prescription; we therefore decline all responsibility for their use for curative, aesthetic or food purposes.