Tlanoxtle

Tlanoxtle (Lycianthes moziniana)
Scientific name	Lycianthes moziniana (Dunal) Bitter
Genus	Lycianthes
Family	Solanaceae
Order	Solanales
Fruit type	Berry
Growth form	Perennial herb from fusiform storage roots
Native range	Central Mexico, mainly the Trans-Mexican Volcanic Belt
Native elevation	1,600 to 3,000 m
Climate and hardiness	Cool to mild highland climate; dies back seasonally and resprouts from underground roots
Mature height	Usually 0.1 to 0.5 m; occasionally to 0.9 m
Soil	Volcanic soils in disturbed fields, pastures, roadsides, and forest clearings
Sun	Full sun to light shade
Germination	N/A
Years to fruit	N/A
Pollination	Solitary bees; self-pollination may occur
Harvest	Mature fruit collected September to December in the native range

Tlanoxtle (Lycianthes moziniana (Dunal) Bitter) is a perennial Mexican food plant in the genus Lycianthes and family Solanaceae, the tomato and potato family. It produces juicy green berries that have been gathered for food and sold in traditional markets. The plant is not a tree: it dies back near or below the soil surface each season and returns from fusiform underground storage roots.^[1][2]

Description

The plant is a low perennial herb, usually 0.1 to 0.5 m tall, although specimens up to about 0.9 m have been recorded. Stems may be green to purple-green, with little woody tissue except near the base. The plant branches sympodially and may become decumbent, ascending, or erect as it grows. White, simple hairs cover the stems and leaves. The underground storage roots allow the above-ground growth to die back during the dry or cool part of the year and then resprout when conditions improve.^[1]

Leaves are simple and occur in unequal pairs on the upper shoots. The blades range from obovate and elliptic to ovate or lanceolate, with entire margins that may be undulate or irregularly angled. Flowers are solitary and axillary, carried horizontally on unusually long pedicels. The flowers have a shallow, round corolla and five poricidal anthers. A green calyx with ten narrow appendages is a useful identification character and helps distinguish Lycianthes from many wild Solanum species.^[1][3]

Identification

Tlanoxtle is most reliably identified when flowers and fruit are present. Look for a low, hairy perennial with long, solitary flower stalks, a ten-appendaged calyx, and green berries whose enlarged fruiting calyx teeth remain appressed to the fruit. The botanical revision recognizes three varieties of L. moziniana; the variety moziniana is the form associated with the traditional food plant and the Trans-Mexican Volcanic Belt.^[1

The name is also written as tlanochtle, tlalnonochtle, or tlanoxtle in regional material. Other recorded names include berenjita, chumpin, chimpina, huevo de gato, tintolón, tilindon, and coyotomate. These vernacular names can overlap with other Solanaceae, so a market or seed packet name should not be treated as a botanical identification without checking the plant's flowers and calyx.^[1]

Climate and site

The food-plant variety is concentrated in central Mexico, especially along the Trans-Mexican Volcanic Belt, at elevations from about 1,600 to 3,000 m. It grows in disturbed pastures, agricultural fields, paths, roadsides, and clearings in xerophilous shrubland, oak forest, and coniferous forest. Field observations from Querétaro recorded flowering at approximately 2,700 m during the summer rainy season.^[1][3]

Native plants are associated mainly with volcanic soils rather than swampy ground. The important soil feature is not constant wetness: the plant occupies open, seasonally managed sites where the root zone is likely to drain and then dry between periods of rain. Give it a mineral, well-drained soil with organic matter, but avoid heavy clay that stays airless after rain. A raised bed is appropriate where winter or summer rainfall leaves water standing. The underground roots can carry the plant through a dry or cold rest, but the active shoots need moisture during the growing season.^[1

This is a highland plant, not a lowland tropical perennial. Full sun and cool to mild temperatures are more appropriate than hot, humid conditions. In climates with freezing winters, mulch over the root zone and expect the top growth to disappear. Growers in warm climates should provide excellent drainage and some afternoon protection if plants decline in prolonged heat.

Propagation

• Seed is a documented natural propagation route. The plant persists through seed dispersed by people as well as through its underground root system.^[1[2] Germination temperatures, storage life, and emergence times: N/A. Sow fresh, cleaned seed in a free-draining medium and keep it warm and evenly moist until emergence.
• Storage roots allow established plants to resprout after seasonal dieback. Avoid damaging them during dormancy and do not keep dormant roots in saturated soil.
• Cuttings and grafting: N/A.

Flowering, fruiting and harvest

Flowering specimens of the food-plant variety have been collected from June through October. Mature fruit has been collected from September through December, placing the main native harvest in the latter part of the rainy season and the beginning of the cooler, drier season. Field observations report that the corollas open very early in the morning and close by noon.^[1]

Solitary bees in the genus Thygater have been observed visiting the flowers. The flower's staggered stamen development may bring the final anther close to the stigma and allow some self-pollination. Reliable fruit-set data for cultivated plants: N/A.^[1][3]

Fruit and uses

The berries are green when mature in the food-plant variety, roundish to oval, juicy, and up to approximately 4.15 cm in diameter. Their flavor has been described as sweet with a slight tartness or acidity, similar in general character to tomato. Fruit is eaten raw and has also been dried, boiled in sugar syrup, and preserved. Tlanoxtle fruit has been associated with traditional markets and offerings during Day of the Dead observances.^[2][3]

David E. Williams reported an estimated field density of about 4,700 plants per hectare, with approximately 30 fruits per plant in one agricultural setting. That observation produced a calculated yield of about 1.25 metric tons per hectare, but it should be treated as a field observation rather than a modern commercial yield standard.^[2]

The botanical revision records medicinal use as a purgative in the State of Mexico. That is not a recommendation for home use. As with other Solanaceae, fruit should only be eaten when the plant is correctly identified and the fruit is at the documented mature stage; unripe fruit, leaves, and underground parts should not be assumed edible from the fruit's food history.^[1]

Pests and diseases

N/A

Cultivars and selections

No named horticultural cultivars were identified. The botanical revision recognizes the varieties moziniana, margaretiana, and oaxacana, but they are not interchangeable in food use or climate adaptation. The food-plant tradition described here applies primarily to var. moziniana.^[1]

Container growing

A deep container is preferable because the plant develops fusiform storage roots. Use a mineral, sharply draining mix and keep the plant in full sun. Allow the top growth to die back naturally if it enters dormancy, then reduce watering without allowing the dormant root mass to remain wet. Resume regular moisture only when new shoots appear.

Zone pushing

• Treat the plant as a cool-season or highland perennial rather than a tropical fruit tree.
• Mulch heavily over the root zone where winter temperatures freeze the top growth.
• In hot climates, use morning sun, afternoon protection, and fast drainage.
• Do not plant it in a low spot where heavy clay stays saturated through winter.
• Preserve seed or root material from authenticated food-plant lines because the traditional agroecosystems supporting Tlanoxtle are declining.^[1][2]

Sources

1. ↑ Dean et al. (2020), “The genus Lycianthes (Solanaceae, Capsiceae) in Mexico and Guatemala,” PhytoKeys 168: 1–333. Taxonomy, morphology, distribution, habitat, phenology, uses, and variety-level discussion.
2. ↑ Williams (1993), “Lycianthes moziniana (Solanaceae): An Underutilized Mexican Food Plant with ‘New’ Crop Potential,” Economic Botany 47: 387–400. Food history, fruit use, field density, yield estimate, and traditional cultivation context.
3. ↑ Jim Conrad, Tlanoxtle, Lycianthes moziniana. Field observations from Querétaro, flower biology, flavor notes, and traditional-use summary.

Image credits

• Botanical figure: Dean et al. (2020), Figure 66, PhytoKeys, CC BY 4.0. Local copy: .
• Field photographs and observations: Backyard Nature, Tlanoxtle.