Panax trifolius - Dwarf Ginseng Home - Plant Profiles & Photos

 > Flowers   > Fruit   > Leaves & Plant   > Habitat    > More Info  open in separate tab

Panax trifolius, dwarf ginseng, is a native perennial herbaceous plant. In any one season, an individual plant can produce either all bisexual (perfect) flowers or all male/staminate flowers. Dwarf ginseng has a very unusual life cycle. In subsequent seasons, the plant can undergoes "sex/gender change". It blooms late April/early May and greenish yellow fruits mature quickly. It is a true spring ephermal and in about 2 months it will be gone underground.

This is in our spring photo gallery collection.

Flowers

Dwarf ginseng has only one flower cluster per plant on the single short vertical stem. The flowers are white and the clusters are less than a inch wide. The individual flowers are less than an 1/8 th inch across. The flowers all have 5 petals and 5 stamens.

Male/Staminate Flowers/Plant 

Male/Staminate Inflorescence - flower cluster: 

The male plant is easier to spot because it flower head is larger and its shape is distinctive

Viewing from the top, the male (staminate) flower head looks ball shaped. The flowers mature starting from the bottom up so the buds are at the center. The third photo is a side view.
Panax trifolius - dwarf ginseng -  male / staminate inflorescence  - flowers mature from bottom Panax trifolius - dwarf ginseng -  male / staminate inflorescence  - flowers top view Panax trifolius - dwarf ginseng -  male / staminate inflorescence  - flowers side view

Male/Staminate - Individual flowers: 

The male flowers have fertile stamens. The female parts are sterile. The photos show a single short style but the pistil is sterile.
panax trifolius - dwarf ginseng - Male Flower showing stamens and non-fertile stigma panax trifolius - dwarf ginseng - Male Flower and non-fertile single stigma panax trifolius - dwarf ginseng - Male Flower - 5 stamens and non-fertile single stigma panax trifolius - dwarf ginseng - Male Flower - 5 stamens and non-fertile single stigma


Bisexual/Perfect Flowers/Plant 

Bisexual/Perfect/Hermaphroditic - Individual flowers: 

The bisexual flowers have both fertile stamens and fertile pistils. The images below show bisexual flowers. The 5 stamens and 3 functional stigmas are apparent. The bisexual flowers are protandrous meaning the anthers are mature before the stigmas.
panax trifolius - dwarf ginseng - Bisexual Flower - 5 stamens and 3 functional stigmas panax trifolius - dwarf ginseng - Bisexual Flower - 5 stamens and 3 functional stigmas panax trifolius - dwarf ginseng - Hermaphoditic Flower - 5 stamens and 3 functional stigmas


Since the plants are protandrous, in dwarf ginseng, it appears here that the finished stamens are completely discarded. We then have what appears to be female plants but are really bisexual plants. We found many plants where all the flowers had only pistils and no stamens. But occasionally, there would be a remnant of a shriveled up stamen indicating that there were stamens but they had fallen off.
The images below show flowers with fertile female stigmas and if you look hard, vestiges of a stamen are there. The pistil is compound with a 3-celled ovary with 3 stigmas. The stigmas are clearly seen. All the flowers on the plant were the same.
panax trifolius - dwarf ginseng - Female Flower- 3 fertile stigmas - no stamens panax trifolius - dwarf ginseng - Female Flower- 3 fertile stigmas - no stamens



Bisexual/Perfect/Hermaphroditic - Inflorescence: 

The cluster of bisexual flowers is smaller with fewer flowers and can easily be distinguished in the field.

In this cluster, all the flowers have pistils and stamens Panax trifolius - dwarf ginseng -  bisexual inflorescence - flowers with functional stamen & pistils

In this cluster, two of the 5 flowers have no stamens, all have pistils Panax trifolius - dwarf ginseng -  bisexual inflorescence  2 of the flowers lost all their stamens

In this cluster, none of the flowers have stamens, all have pistils Panax trifolius - dwarf ginseng -  bisexual inflorescence - all the stamens have fallen off



Life Cycle & Sex/Gender Change 

When the dwarf ginseng plants are very small they do not bear flowers and only produce leaves. When they are first large enough to have flowers, the flowers will be male. Producing pollen requires less stored energy. When the plants are large enough (have enough stored energy), they will produce bisexual flowers. These bisexual plants with functional pistils, after pollination, will be able to produce fruit and consequently will need more stored energy to support the seed production process. This has often referred to as a "sex change". After producing seed, the plant will in the following year most likely produce male flowers.

Studies have shown that the plants can alternate between the two different genders during their life time. It has been estimated that every year about one fourth to one third of the plants in an area switch from producing one kind of flower to the producing the other. This a rare sexual system.

Both forms of the plant produce viable pollen. Comparing the male plant stamens to the bisexual plant stamens, studies have shown that the male plants produce more flowers - 2-3 times more. The male plant anthers produce more pollen per anther, about 1.2 time more. The male plant pollen is available for a longer time and the timing coincides closely with the time the stigmas are ready. The bisexual plant stamens produce pollen for a shorter period of time and the pollen is available before the stigmas are ready discouraging self fertilization and favoring cross pollination by the male plants.

 


Return to Top


Fruit

After the female and bisexual flowers are fertilized, the fruits begin to develop. The base of the flowers, ovary, with functional pistils start off relatively broader and develop further as the fruits mature. The leaves turn yellow and the plant falls over

The petals fall off, the stigmas remain. Stamens are not apparent in the first photo below. In the first 2 photos, the leaves are still functional. The base of the flower, ovaries, expand. In the last 3 photos, the fruit may be ripening but resources from the leaves are diminishing. In the last photo, two fruits are ripening and two have aborted.
panax trifolius - dwarf ginseng - Fruit panax trifolius - dwarf ginseng - Fruit panax trifolius - dwarf ginseng - Fruit panax trifolius - dwarf ginseng - Fruit panax trifolius - dwarf ginseng - Fruit


Return to Top


Leaves and Plant

The single stem of the plant terminates in a whorl of compound leaves and a single flowering stalk close to the ground. The whorl of 3 leaves each with 3-5 leaflets. Individual leaflets are 0.75 to 1.5 inches long. The plant including the flower is about 3 - 8 inches tall. Underground, each plant has a small corm about the size of a pea which is the perennial energy storage part of the plant.
panax trifolius - dwarf ginseng - whorl  of 3 leaves each with 3-5 leaflets panax trifolius - dwarf ginseng - plant with flower is about 3 - 8 inches tall panax trifolius - dwarf ginseng - plant with flower is about 3 - 8 inches tall


 

Return to Top

Habitat

Dwarf ginseng grows in moist humus rich soil in shady areas in hardwood forests. In NJ it is found mainly in the north . Photos show the leaf litter and some companion plants - trout lily and wild lily of the valley.

panax trifolius - dwarf ginseng - Habitat panax trifolius - dwarf ginseng - Habitat


 


Text by Millie Ling. All photos by Hubert & Millie Ling. Photos taken April 6, to June 1, 2020 and April 28, 2022 in the Morris County.


Return to Top

Additional information

Additional information / references:

References on life cycle & "sex change":

Mark Schlessman has done many scholarly studies on dwarf ginseng. Here is one:

Article can be downloaded from here: https://www.researchgate.net/publication/271774861_Floral_Phenology_of_Sex-Changing_Dwarf_Ginseng_Panax_trifolium_L_Araliaceae 

Excellent readable discussion and gives many references: https://www.discoverlife.org/nh/tx/Plantae/Dicotyledoneae/Araliaceae/Panax/trifolium/

Article from Georgia: https://georgiabiodiversityportal.org/natels/profile?es_id=16616

Plant descriptions and photos:

This site always has good descriptions: https://www.minnesotawildflowers.info/flower/dwarf-ginseng

This site always has great photos : https://www.delawarewildflowers.org/plant.php?id=1382 


 

Return to Top