Finger Lime - Microcitrus australasica

The Finger Lime, Microcitrus or Citrus australasica in Latin, is the trendy citrus fruit that top chefs around the world are clamoring for. Rare and sought after, it is still relatively unknown to amateur gardeners, despite its playful appearance and compact size, which makes it well-suited for pot cultivation. This small Australian lemon tree is a bushy shrub with slender branches that bear tiny leaves and thorns, and produces small fragrant white flowers, followed by fruits in various colours, hardly bigger than a finger. Their pulp is composed of small juicy and crunchy beads that burst in the mouth, revealing delicious tangy and aromatic flavours. This chic and unusual citrus tree should be cultivated in a large container and stored in a greenhouse during winter, or planted in the ground in warm regions that are not affected by heavy frost.

The Finger Lime, also known as the 'caviar lime' or 'Australian finger lime', due to the size and shape of its fruits, which can also resemble gherkins. It is a small thorny shrub of the Rutaceae family, with a rather upright bushy habit. It is native to the eastern part of Australia, where it grows in moist woodland undergrowth. This small tree reaches a height of 3 m and spreads to about 2m (7ft) in the ground, but will remain more compact when grown in a pot. Not very hardy, it can be planted in the ground in narrow coastal areas of the Mediterranean. Elsewhere, it should be grown in a pot and stored away at the first signs of frost. Cultivated for its leaves and fruits, the Finger Lime blooms in March-April. It produces pink buds that open into small white flowers with a sweet and delicious neroli fragrance, characteristic of Citrus trees. The fruiting process is quite slow for this citrus, which needs time to reach maturity. The flowers give way to cylindrical, digit-shaped fruits, measuring 4 to 8 cm (2 to 3in) in length. Once fully ripe, the skin of the fruits can display various colors, ranging from green to black, yellow, red, and brown. The fruits contain small vesicles that naturally separate from each other, resembling caviar, with a variety of colours, juicy and crunchy. The fruits are harvested from October to December. They can be used to enhance both savoury and sweet dishes. The evergreen aromatic leaves of this citrus measure 1cm (0in) to 6cm (2in) in length and 3 to 25mm (0 to 1in) in width. They have a very delicate aromatic flavor, used as a spice.

The Finger Lime is cultivated frost-free, in a slightly acidic and always moist soil, and in a humid atmosphere, requirements that are easier to meet when grown in a large pot. In-ground cultivation is almost a specialist matter for this species, which is sensitive to temperatures below -3°C (26.6°F). The Finger Lime fruit is a refined and sought-after delicacy, with prices reaching several hundred euros per kilogram. Like truffles, it should be used sparingly to decorate a plate or flavour a dish. This citrus-condiment adds a pleasant tangy and aromatic note to seafood dishes such as oysters or almonds, for example. It pairs well with the flavour of scallops or thinly sliced salmon fillets prepared as carpaccio. It can also be incorporated into fruit salads or cocktails, adding crunchy beads.

Like all Citrus trees, the Microcitrus contains essential oil pockets in its leaves, flowers, and fruits, which can often be seen with the naked eye. These can be extracted by distillation (flowers and leaves) or by pressing (zest) to obtain essential oil with anti-inflammatory, anti-rheumatic, and sedative properties, helping to combat stress and insomnia. The fragrance of the essential oil is described as fresh, citrusy, tangy, with green notes.

Most citrus trees thrive in the ground in Mediterranean coastal regions, where they can enjoy the necessary year-round warmth. However, to fruit well, they must not lack water or nutrients. The Finger Lime is not very hardy and starts to suffer from cold temperatures below -3°C (26.6°F). It is a self-fertile shrub, which means that a single individual is sufficient for complete pollination and fruiting.