In December 1945, I wrote an article for Plants and Gardens, the Brooklyn Botanic Garden serial, entitled “Poinsettia: Mystery Flower.”
Now, seven years later, I am glad to have the opportunity to correct any false impressions I may have given in that article and add further information.
First, before going into the nature of the “mystery,” I shall describe the botanical characteristics of this particular flower.
Poinsettia’s Botanical Characteristics
It is by no means a flower of the ordinary, orthodox sort, with sepals, petals, stamens, and pistils in regular sequence and arrangement.
The poinsettia’s actual flowers are the small greenish structures in the center of the rosette of bright, flaming red bracts or floral leaves. These lifelike flowers are strange indeed.
A hollow, green, rounded structure with a circular opening at the top, like a teapot without a lid, contains the “flowers.”
A single stamen is a flower; several of these flowers are borne within the hollow structure along with a pistillate, or “female,” flower.
These two kinds of unisexual flowers do not protrude simultaneously from the cup, or “cyathium,” as it is technically called; this feature is a device to ensure cross-fertilization.
The structure appearing outside the cyathium and resembling an ugly mouth contains nectar, which attracts insects and even small birds in the tropics. So much for the actual flowers.
The glory of the poinsettia rests in its bright red floral bracts, and large, crimson (or in some variations, cream color or pink) leaves radially arranged about the flowers. These, it is evident, also attract the attention of birds or insects.
Becoming A Popular Christmas Plant
These brilliantly-colored leaves have given the poinsettia its widespread and increasing popularity as a Christmas plant.
In fact, in Central America, where it is said to be native, the plant is called “Flor de Pascua,” or “Christmas flower,” or simply “Pascua.” Its time of flowering coincides nicely with the Christmas season.
Dr. Joel R. Poinsett, United States Minister to Mexico, saw this plant in 1828 and brought it to the United States for cultivation. Hence, it received the name poinsettia in his honor.
Still, it had earlier been labeled Euphorbia puleherrima. Since there is no valid reason why a new genus should be made, the older name is now generally accepted among botanists.
Mysteries Of Poinsettia Flowers
So much for the flowers. Now we come to the “mystery.”
What is the native home of the poinsettia? In other words, where does it grow wild without the tender care of the gardener?
I have searched the literature and found only scant descriptions of its native habitat.
In his new Flora of Guatemala, Dr. Paul Standley says: “It seems to be uncertain where the poinsettia is native, and in Central America, it usually is confined to hedges and gardens.
However, we have found it in several departments of Guatemala, in localities where it appeared to be a native plant, remote from any dwelling, and in places where it seemed improbable that any dwelling had ever been.
It grew in a dense forest in Quebrada (ravines), on steep, rocky banks or cliffs, which may be its native habitat.
It is, of course, possible, but not very probable, that birds had introduced the plant or had been planted about some former shrine, but this seems unlikely.”
One German authority says it grows in “feuchten, sehattigen Standorten.” Then one sees, in his mind’s eye, colonies of the plants flaunting their brilliant leafy rosettes with unrestrained abandon.
In my former article in Plants and Gardens, I inserted a plea for visitors to Mexico to bear this problem of the native habitat of the poinsettia in mind and send me any further information.
It was only a few weeks later that my sister, while on an auto trip from Mexico City to Acapulco, saw the plant on the bank of a dry arroyo near the road but far from any houses and, therefore, apparently wild. The plant was about 6′ feet high and fully bloomed (Feb. 1946).
Professor A. J. Sharp of the University of Tennessee wrote me in January 1947 that he saw it growing wild, lie thought, in the virgin forests of Sierra Madre del Sur along the trail from Mapastepee to Liquidambar, Chiapas, Mexico.
And Sr. Ephrata Hernandez of the Rockefeller Foundation in Mexico City writes that he saw it growing wild in Guerrero.
Given these partly indecisive statements, the suggestion has been made by some authorities that the poinsettia is a cultigen, that is, a plant “with no determined nativity, presumably originating (in the form in which we know it) tinder domestication.”
Although several of these euphorbia relatives have similar characteristics, such as Euphorbia marginata, snow-on-the mountain, whose leaves are rimmed with white, and the common spurge, Euphorbia cyparissias, whose yellow-green floral bracts make some little show.
One would think that such a significant modification from these lowly plants to the form we see in the gorgeous poinsettia can hardly have arisen full-fledged in cultivation.
Nevertheless, a flair for variation indeed exists within the species itself. We have already mentioned the pink and cream-white varieties.
There is also a double variety in which the growing points giving rise to the flowers do not stop but continue to form new flowers and bracts for many months.
The Mystery Ends
As this article was being prepared, we received a letter from Dr. Eizi Matuda of the Herbario Nacional, Institute de Biologic, Chapultepec, Mexico, D. F. Dr. Matuda states that there is no doubt that the plant is a native of Mexico.
With a relatively broad distribution from the central part of Mexico to Chiapas, it grows in wet, rocky ravines, with the faculty of resisting drought in dry seasons.
So ends the “mystery.” Yet we should like someone to describe the habitat in more detail, giving, of course, the geographic locality, and naming the companion species, noting the light and shade requirements, the soil, including moisture conditions, the altitude, and finally, if possible, obtaining a photograph of the plants and the surrounding terrain.
44659 by Arthur Harmount Graves