Sea onion

Sea onion

Sea onion

Specification & Spread

Sea onion bulbs – bulbi scillae
Sea onion – Drimia maritima = Urginea maritima
Hyacinthin family — Hyacinthaceae
It is a perennial herbaceous bulbous plant up to 100-150 cm tall.
The bulb is large, weighing 2-8 kg.
The elevated part is represented by basal leaves and leafless flower stem.
The leaves are in the amount of 10-20, narrow-ovate or lanceolate, entire, glabrous, arcuate and 30-60 cm long.
The flowers are with the right simple coronoid hexamerous perianth, collected in a large (up to 40 cm) dense racemose.
The fruit is a seed case.
There are two varieties: white and red.
The white variety has flowers with a greenish-white perianth. The internal palea of the bulb are white or slightly yellowish (found on the European coast of the Mediterranean Sea).
The red variety has flowers with a pink perianth. The inner bulb is purple or pink (found on the African coast of the Mediterranean Sea and in South America).
It blooms in September – October and fruit bears in November.
Spreading and habitat. It grows in the Mediterranean countries from the Canary Islands to the coast of Syria on the coasts, in dry desert places.It also grows in South America (Brazil, Chile, Colombia, Venezuela). In Russia, it is not cultivated.


In the bulbs of the white variety, about 10 substances belonging to the butadienolides were found. The main one is glycoscylaren A (⅔ the amount of glycosides).
Glycoscylaren A is a primary trioside formed by aglycone – scillipicrin, rhamnose and two glucose molecules.
During hydrolysis, bioside scillaren A is formed first, and then rhamnoside – procilaridin A.
In addition to bufadienolides, the bulbs contain:

  • 4-11% of mucus,
  • bitter substance – scillipicrin,
  • traces of essential oil.

In the bulbs of the red variety, monoglucoside is found to be scilliroside, the genin of which — scillirosidine — differs from scillarenin by hydroxyls at C6 and C8, and at C6 hydroxy is acetylated.
Scillirozide is very toxic for rats, and scillaren A acts less on them.

Harvesting and storage of raw materials

Harvesting. The bulbs are harvested for 8-10 years of plant life, in May – June. They are dug up, remove the outer dry palea, cut the bottom, which is used for planting.
Drying. Succulent palea is dried in the sun. It is necessary to observe precautionary measures (respirators), since fresh bulbs have a strong odor caused by disulfide compounds of the essential oil.

For medical purposes, only the dried internal palea of the bulbs of the white variety are used. These are yellowish-white, flat or curved pieces of various shapes, pellucid, hard, corniculate, 1-8 cm long and 5-10 mm thick.
The smell is weak. Hygroscopic. Taste is not determined!

Properties and application

Pharmacotherapeutic group. Cardiotonic agent (cardiac glycosides).
The pharmacological properties of sea onion
The effect is close to strophanthus.
At the same time it causes a strong diuresis, because the palea also contain the bitter glycoside – scillipicrin, which has a diuretic effect.
Application of sea onion
The bulbs of sea onion of a white variety are included in the pharmacopoeias of a number of European countries (France, Great Britain, etc.).
It is medicated as:

  • cardiotonic and
  • diuretic agent and
  • used for the production of cardiotonic agents.

The bulbs of the red variety were used for rodent control.
Along with sea onions, Drimia indica (Roxb.) Fessop (= Urginea indica) bulbs (India, Pakistan) are used, which in commerce are called «Indian sea onion». This species is adopted by the Ayurveda medical system.

The preparations cause irritation of the renal parenchyma (kidney disease), pregnancy and lactation, pediatric use, individual intolerance.