Many similarities to : Cape Gooseberry (Physalis peruviana) which belongs in the same genera but that has pale-greenish lantern, the flowers have five pointed yellow petals (rather than white), and the fruit is yellow (rather than orange). Two other similar Physalis plants are
Tomatillo (Physalis ixocarpa) with green to purple fruit which (unlike Japanese Lantern) completely fills the calyx tube and the similar but usually larger-flowered
Large-flowered Tomatillo (Physalis philadelphia) - however, sizes overlap somewhat. All 4 Physalis species are non-native plants which are planted in gardens from where they may escape.
Some similarities to : Orange-Peel Clematis (Clematis tangutica) but this has only four petals (rather than the 5 of Japanese Lantern) and are yellow (rather than white) and which initially forms a similarly drooping and apparently closed pointed structure but, unlike the orange caged-sepal of Japanese Lantern, these are not fused together and will open slightly.
Superficial resemblance to : Apple-of-Peru (Nicandra physalodes) but that has a pale-blue to white flower.
Uniquely identifiable characteristics
Distinguishing Feature : The bright orange pendant calyx tube which looks like a lantern.
The flowers are white with 5 petals (not shown). After flowering the petals drop off and the calyx inflates to form a bright orange cage structure with 10 axial ribs which will nurture the ripening spherical fruit, (not shown), which is also bright orange.
The concolorous spherical fruit is soft, tomato-like containing many small seeds and edible, possessing more vitamin C than do lemons. They are sometimes used as a garnish in posh restaurants (indeed, your Author remembers having one - but at the time had no idea what it was), as are Cape Gooseberry and
Tomatillo fruits. However, no other part of these poisonous plants are edible! The dried fruit of Japanese Lantern is used as a diuretic, antiseptic, liver corrective and as a sedative.
The plant is reported to have medicinal properties such as anti-gout, anti-inflammatory, antibacterial, anti-mitotic, analgesic, laxative, diuretic, leishmanicidal and is also anti-malarial.
The plant contains various substances such as alkaloids, glucocorticoids,
Lycopene, ethanolic compounds and Vitamin C. Of particular note are a tropane alkaloid and a few Physalins (named after the genus of plants in which they are extensively found) being steroidal compounds with an unusual structure. A
phenylpropanoid glycoside called
Cuneataside E is also to be found within the plant. Also the ethyl ester of Caffeic Acid -
A NORTROPANE ALKALOID
The roots contain a
norTropane alkaloid similar to many Tropane alkaloids contained within other species of Solanaceae, but this one, 3α-TigloyloxyTropane, has an unusual
Tigloyloxy side-group attached and is an ester.
PHYSALINS - STEROIDALS
Physalins are similar to Steroidal compounds, but one of the bonds is broken near the centre of the molecule and instead the topmost group has an additional bond completing a hexagon. The physalins are not alkaloids for they lack any nitrogen atoms and consist solely of C, H and O atoms (as do steroidal compounds). The three Physalins shown are also ketones. All four Physalins shown are to be found in Japanese Lantern. More than another eight Physalins exist which are synthesized by other species of Physalis.
Physalin A is the simplest of the physalins, but compared to the physalin skeleton shown above there are three additional rings, one completed by an epoxide-bridge (-O-) across the middle-centre to make a new 5-membered ring, a second by a 5-membered ring with a ketone oxygen atom (centre top) and the third by a lactone (top-most right-most). Physalin A is a quadruple ketone, possessing four =O bonds, as are all the Physalins depicted here.
Physalin B has one more ring than Physalin A, a 7-membered ring which also includes a peroxide linkage. Physallin B and Physalin D are pronouncedly polycyclic with a 6-membered ring with a heterocyclic oxygen atom pinning and pulling two other ring systems together and probably making more noticeably 3-dimensional. This probably also increases their toxicity since 3-dimensional substances can generally react with biological molecules more readily.
Physalin D is similar to Physalin B but with two extra -OH side-groups (bottom left) and the subsequent elimination of a double bond in the second hexagon. Physalin D is also found in Physalis angulata, together with other Physalins which are not found in Japanese Lantern. It has anti-malarial and antimycobacterial properties, both aerobic and non-motile. These pathogens are responsible for diseases such as tuberculosis and leprosy.
Physalin L differs from all the other Physalins shown here in two ways. The first is that the 5-sided ring (centre top) now has a heterocyclic oxygen atom making it also a lactone (besides the lactone in the 6-membered ring at top right. The second way it differs is that the first double bond on the left-most 6-membered ring has moved anti-clockwise by one position. Japanese Lantern also contains 25,27-dehydroPhysalin L (not shown).