ICHU: CHARACTERISTICS, TAXONOMY, HABITAT, CARE AND USES - BIOLOGY - 2024

The ichu (Stipa ichu) is a perennial grass belonging to the Poaceae family. Its growth is vertical and grouped, with green foliage, turning golden in late autumn. The inflorescence is racemose, with white or silver flowers that grow from the base, simulating hanging spikes.

Ichu is a grass typical of the South American Andean highlands and of some Central American countries, such as Mexico and Guatemala. This species receives various names, among which are Peruvian grass needle, wild straw, ichchu, pecoy, puna straw and Peruvian feather duster.

Stipa ichu. Source: Cristian Ordenes, via Wikimedia Commons

Recent studies on ichu recognize the genus Jarava Ruiz et Pav for South America. This includes all species treated within Stipa L. sl. To create the genus Jarava, the researchers relied on Jarava ichu. Later, the new genus was considered a section or subgenus of Stipa L.

In 1997 some anatomical, morphological and molecular aspects of Jarava were revealed. These provide important data for it to be accepted as a separate genus from Stipa L.

characteristics

Stipa ichu is a herbaceous plant that grows upright and in groups, forming clumps. Its stem measures approximately between 60 and 180 centimeters, each one having more than 3 nodes.

The knots may be hairy or not, while the internodes are hairy and rough in texture.

Leaves

The leaves are filiform and rigid, with a glabrous base. They are usually between 30 and 60 centimeters long and less than 4 millimeters wide. On the neck they have hairs of around 1 millimeter long and at the junction between the leaf blade and the sheath they have a membrane 2 millimeters long.

The blade or lamina is folded or has the edges bent towards the inside. This structure is rough in texture, or it could have hairs in the bundle.

flowers

The ichu inflorescence is an open panicle and densely flowered from its base. It can be silver or white in color. It is 15 to 40 centimeters long and its knot has light brown or white hairs.

The panicle or panicle is narrow, flexible and silky, being able to have long edges during autumn and summer. The spikelets, on which the flowers are placed, have a short pedicel

The flowers are hermaphroditic and have purple or hyaline glumes. The length of these is 6 to 10 millimeters and they are about 1 millimeter wide. They are trinervated and are long acuminate.

The bracts are spindle-shaped, measuring between 2 and 3.5 millimeters long. They are light brown in color and have white hairs. The edges, which extend from the lemma, are long, flexuous and can be glabrous or rugged.

Taxonomy

Kingdom Plantae.

Magnoliophyta Division.

Class Liliopsida.

Poales Order.

Poaceae family.

Subfamily Stipoideae.

Stipeae tribe.

Genus Stipa

Species Stipa ichu (Ruiz & Pav.)

Habitat and distribution

Stipa ichu is native to Costa Rica, Mexico, Guatemala and El Salvador. In South America it is endemic in Venezuela, Ecuador, Colombia, Peru, Argentina and Bolivia.

It is found abundantly in the High Andean phytogeographic province, located at an altitude between 3,700 and 4,800 meters above sea level. There, in the open field, it forms extensive grasslands.

This species can grow in steep ravines, mountain slopes, pampas, hills, and on the banks of rivers. In these regions, the soil is moist and fertile. It must also have good drainage, since it does not develop in flooded lands.

The ichu is part of the vegetation of the Puna ecoregion, located in the central highland area of ​​the Andean mountain range. It is also found in forest clearings and in some disturbed places, such as secondary grasslands and on the edges of roads or of the plots.

The habitat of the Stipa ichu can be found from the Mexican plains, with a warm desert climate, to the high mountains of Peru, an area of ​​high altitude and low temperatures. This characteristic of the species gives it a condition of great resistance and adaptability that favors its development.

Care

The plant can be planted, among other spaces, on the edges of garden paths, in patios and in parks. In these places, it is usually accompanied by herbaceous species in vivid tones, thus creating a great contrast of textures and colors.

Experts recommend sowing between 3 and 5 plants per square meter. The soil must be nourished and not floodable. Drainage is extremely important for the development of Stipa ichu, so it is recommended that the soil be mixed with a portion of sand, thus avoiding its compaction.

The planting site should be exposed to direct sunlight, or failing that, be under little shade. Its irrigation is moderate, adapting to the environmental conditions of the place.

Maintenance

The ichu plant requires little maintenance. To keep the plant looking neat, it is important to remove dry or old branches and inflorescences. This is recommended to do at the beginning of spring.

It is also convenient to divide the clumps periodically, thus maintaining the vigor of the plant. One of the advantages of this species is that it is not attacked by pests and very rarely suffers from any type of disease.

There is a technique that minimizes the need for pruning the plant, it is known as brushing. To do it, take a portion of the grass and, using an unused hairbrush, brush it from the bottom to the top.

If there are dry leaves, it is important to cut them. Once a section has been brushed, another is continued until it is done throughout the plant.

Applications

Stipa ichu is an important part of the diet of South American camelids, which live at high altitudes in various regions of the Andean mountain range. Among this group of animals are the llama, the vicuña, the alpaca and the guanaco. Also some equine species and vaccines forage this herb.

The leaves are used to hand-pack some fruits, such as prickly pear and various foods such as cheese. The inhabitants of the Andean highlands make mats and baskets with the dried leaves of the plant. They also manufacture roofs for homes in the area.

There are projects based on the manufacture of cold-insulating panels, in order to be used to build houses in those regions where the temperature reaches below zero levels.

The ichu plant is highly valued for its ability to prevent erosion of the soil where it lives. However, the peasants in the area often burn it with the wrong intention of fertilizing the land.

Due to this situation, awareness campaigns have been carried out that emphasize the disadvantages of burning pastures, with environmental pollution being one of the most damaging problems.

Recent research

Thanks to the work of a group of researchers, the anhydrous bioethanol compound was obtained from Stipa ichu. For this, an extractive distillation process was carried out, starting from the crushing of the dry material from the plant.

The relevance of this discovery lies in the fact that bioethanol can be used as a fuel or as a gasoline additive. Its production could displace the one that has a fossil origin, which is one of those responsible for the high pollution suffered on planet earth.

References

1. Wikipedia (2018). Jarava ichu. Recovered from en.wikipedia.org
2. Andina- Peruvian News Agency (2017). They propose the use of ichu as a thermal insulator for homes in the Andean region. Recovered from andina.pe.
3. Carlos Reynel (2012). Identification guide of the common plants of the right of way of the Peru Lng pipeline. Recovered from perulng.com.
4. Eliana Linares Perea (2000). Ethnobotany of the yura-chivay transect, department of Arequipa, Peru. San Agustín University, Arequipa. Peru. Recovered from chlorischile.cl.
5. D. Clayton, M. Vorontsova, KT Harman & H. Williamson (2016). Stipa ichu KEW Royal Botanical Gardens. Recovered from kew.org.
6. SEINet (2019). Jarava ichu. Recovered from swbiodiversity.org
7. Albarracín K.; Jaramillo L.; Albuja M. (2015). Obtaining Anhydrous Bioethanol from Straw (Stipa ichu). Recovered from revistapolitecnica.epn.edu.ec
8. Patricio Peñailillo (2002). The genus Jarava ruiz et pav. (stipeae-poaceae): delimitation and new combinations. Recovered from scielo.conicyt.cl.