The Chinese Lantern plant (Physalis alkekengi) is a perennial species celebrated for the dramatic, decorative structures that follow its unassuming white summer flowers. These unique, papery husks appear in late summer and autumn, resembling miniature paper lanterns. These ornamental structures protect the fruit and the seeds within. Understanding the seeds requires examining this protective layer and the small, fleshy berry that contains the reproductive material.
The Distinctive Calyx
The most recognizable feature of the Chinese Lantern plant is the inflated, lantern-shaped structure, which is botanically identified as the persistent calyx. This calyx is formed from the sepals, the small leaf-like parts that initially enclose the flower bud. After the small, white flower fades, the calyx begins to enlarge dramatically, inflating and completely enveloping the developing fruit.
This protective covering transitions from pale green to a brilliant orange or orange-red shade as the fruit ripens inside. The papery texture of the calyx acts as a physical barrier, protecting the developing fruit from pests and the elements. The calyx often persists through winter as a skeletal, dried husk, making the plant highly valued for dried floral arrangements.
Detailed Description of the Seeds
The seeds are found inside a small, spherical berry, which is the actual fruit developing within the protective calyx. This berry is typically about 15 to 17 millimeters in diameter, resembling a small cherry or tomato, and turns red when ripe. The seeds themselves are quite small and numerous, packed within the fruit’s juicy pulp.
Each seed is generally flat and disc-shaped, sometimes described as slightly curved or kidney-shaped. They measure approximately 1 to 2 millimeters across. The color of the mature seeds is light, usually appearing as a pale yellow, light tan, or off-white hue, and their surface texture is smooth.
Extracting and Planting the Seeds
To collect the seeds, wait until the calyx is fully colored and dried, signifying the fruit inside is ripe. The small, fleshy berry must be removed from the papery calyx and opened to access the seeds within the sticky, moist pulp. The seeds need to be cleaned before storage or planting. Cleaning involves gently crushing the berry in water to separate the seeds from the fruit flesh, allowing viable seeds to sink while the pulp floats.
After cleaning and drying the seeds for a few days, they can be planted indoors six to eight weeks before the last expected frost. Sow the seeds on the surface of the soil, or cover them with only a very thin layer, as they require light to germinate successfully. Under warm temperatures (68 to 77 degrees Fahrenheit), germination typically takes two to four weeks.
Safety Warning Regarding Ingestion
The Chinese Lantern plant belongs to the nightshade family, Solanaceae, and should be treated as an ornamental species. All parts of the plant, including the leaves, stems, and the papery calyx itself, contain steroidal compounds like physalins and are considered toxic. Ingestion of these parts can cause stomach upset and other adverse reactions.
Varieties of Physalis alkekengi should not be confused with the culinary Cape Gooseberry (Physalis peruviana). The small, red berry inside the lantern is sometimes referred to as edible when fully ripe, but the unripe, green fruit is particularly dangerous and can lead to serious poisoning. Therefore, all plant material, including the seeds and berries, should be kept away from pets and small children.