Stanhopea radiosa

Lemaire 1859 (1860)

Native to the Pacific coast of Mexico.

Updated 16 May 2007

19th C lithograph of Stanhopea radiosa
Stanhopea radiosa is native to the Pacific slopes of western Mexico, growing on rocks or trees in deciduous forest, 750-1,500 m elevation (McVaugh 1985). The flowers appear June through August and are scented of cinnamon.

Sepals and petals are pale green with purple-red spots; petals are more spotted, and sometimes orange-yellow at the base. The dorsal sepal is boat-shaped. The lip is fleshy and yellow to white, with a orange-yellow sac-like hypochile. The horns are somewhat flat and approx. 2.5 cm long. The apex of the lip is subtruncate, rounded with a short acumen, or 3-pointed. The column is slender, with hyaline wings.

This species first appeared in the Belgian publication L'Illustration Horticole, journal special des Serres et des Jardins Vol. 6: misc. 72, with two accompanying figures (including the lithograph at right, Plate 270, done by C.H. Lemaire); published in 1859 by Ambroise Verschaffelt. This lithograph was reproduced on the cover of the German orchid publication, Die Orchidee 39(3) in 1988.

The Index Kewensis contains the notation that this species is the same as Stanhopea saccata. McVaugh (1985) says that while Stanhopea radiosa may be the "Stanhopea saccata" of some authors, it is "probably not of Bateman, 1838."

Dodson (1975) wrote that the range of Stan. radiosa is from Sonora to Oaxaca, whereas Stan. saccata is found only in Chiapas and Central America.

However, Kennedy (1975) wrote that there were probably intermediates (natural hybrids) between Stan. radiosa and Stan. saccata, and that these two species were probably not really seaparated by the Isthmus of Tehuantepec.

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Photo of Stanhopea radiosa by Noble Bashor

Barney Greer writes about this species:
"Stanhopea radiosa occurs from the northern Pacific slopes of Mexico down to about the Isthmus of Tehuantepec. It is rare in collections, often being confused with Stanhopea saccata but the epichile of S. radiosa is not deeply enfolded as in S. saccata, making room for a larger pollinating bee. Note: the hypochile on s. radiosa is squarer than that of S. saccata and there is a broad tooth on the upper side of the epichile."

The photograph of the mounted plant at left was taken by Noble Bashor, who collected this plant in Mexico and provided the following notes: "Stanhopea radiosa Lem, nb#1663, Nayarit Mx., 914 m elev., west of La Liberdad, Epiphytic on large Oaks." Used with permission.


The two photos below were taken by Lois Greer, who grew this plant in northern Louisiana. She says the plant may have originated with Herman Pigors of Oak Hill Gardens, and was labeled Stanhopea saccata. It blooms in Oct/Nov and had nine inflorescences the year it was photographed.

Note the differences in the pseudobulbs in the photos at right and above. The basket-grown plant has shiny, plump bulbs with few ridges, whereas the mounted plant (shown above) has more deeply ridged and furrowed pseudobulbs. In general, outside of the Tropics, it seems difficult to keep mounted stanhopeas sufficiently moist in cultivation and they are usually better off in baskets.

In the photo at left, note the relatively flat epichile of the lip, compared with the more folded and deeply furrowed epichile of Stanhopea saccata.

Photo by Lois Greer Photo by Lois Greer

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Die Orchidee cover Printed References:

Authors?? (1988) Die Orchidee 39(3): 91-130 [color cover illustration of Stanhopea radiosa Lemaire] Link: http://www.dog-nordbayern.de/orchidee/1988/titelblatt.htm

Oakes Ames and Donovan Stewart Correll (September 25, 1953). Orchids of Guatemala, in: Fieldiana, Botany 26(2): 399-727. Chicago Natural History Museum. [= Part II of the 1985 Dover Edition.]

Oakes Ames and Donovan S. Correll (1985 reprint) Orchids of Guatemala and Belize. New York: Dover Press, 779 pages [pp. 528-536, 755: Stanhopea devoniensis, S. Hernandezii, S. tigrina, S. ecornuta, S. Lewisae, S. oculata, S. quadricornis, S. saccata, S. radiosa, S. Marshii]

Kenneth J. Curry, Lorraine M. McDowell, Walter S. Judd, & William Louis Stern (May 1991) "Osmophores, Floral Features, and Systematics of Stanhopea (Orchidaceae)," in: American Journal of Botany 78(5): 610-623. "The floral fragrance glands (osmophores) of 18 species of Stanhopea and Sievekingia were examined through a series of developmental studies at light and electron microscope levels including late bud stages through postanthesis." [Sievekingia; Stanhopea anfracta, annulata, candida, ecornuta, gibbosa, martiana, oculata, pulla, radiosa, ruckeri, saccata, shuttleworthii, tigrina, vasquezii, and wardii] Link to abstract: http://www.botany.org/ajb/00029122_di001922.php

Calaway H. Dodson (1975) "Clarification of some nomenclature in the genus Stanhopea (Orchidaceae)," in: Selbyana 1(1): 46-55. [wrote that Stanhopea radiosa Lemaire is present in southern Sonora].

Barney Greer (1998) The Astonishing Stanhopeas (the upside-down orchids). Sydney: Australian Orchid Foundation. 92 color pages, including 55 known species and five natural hybrids.

Rudolf Jenny and Gonzalez Tamayo, R. (1997) "The Gongorinae: 7. Stanhopea: part 16," in: Caesiana no. 9, pp. 21-40. [Again Stanhopea maculosa from Mexico, Stanhopea saccata Bateman, Stanhopea radiosa Lemaire, and a new species, Stanhopea pseudoradiosa Jenny et Gonzalez Tamayo]

George Kennedy (Sept-Oct 1975) "The Stanhopeas of Mexico," in: Orchid Digest 39(5): 178. [includes Stanhopea graveolens, hernandezii, maculosa, martiana, oculata, radiosa, saccata, tigrina]

Charles H. Lemaire (1859, 1860) "Stanhopea radiosa," in: L'Illustration Horticole Journal Spécial des Serres et des Jardins, Plate 270, Published by Ambroise Verschaffelt, Belgium.

Ray McCullough (1996) "Culture of Various Thin-Leafed Orchids," a Synopsis of Ray McCullough's talk at the 3/10/96 Ann Arbor OS meeting. [Houlettia tigrina; Stanhopea intermedia, S. graveolens, S. costaricensis, S. martiana, S. grandiflora, S. eburneum, S. oculata, S. wardii, S. ecornuta, S. connata, S. saccata, S. radiosa, S. tigrina]

Rogers McVaugh (28 June 1985) Flora Novo-Galiciana, A Descriptive Account of the Vascular Plants of Western Mexico, Vol. 16: Orchidaceae. Ann Arbor: The University of Michigan Press, pp. 343-344. [Stanhopea intermedia, maculosa, martiana, radiosa, plus discussion of doubtful species such as: oculata, saccata] -- includes text and full page line-drawing, fig. 113.

Norris H. Williams and W. Mark Whitten (Aug. 1999) "Molecular phylogeny and floral fragrances of male euglossine bee-pollinated orchids: A study of Stanhopea (Orchidaceae)," in: Plant Species Biology 14(2):129-136. ["As would be expected from morphology and fragrance data, S. radiosa Lemaire is a member of a clade with S. saccata Bateman."]


Web References:

International Plant Names Index [IPNI; incorporating IK and GCI], www.ipni.org.

Index Kewensis

Jens Knapp's pages


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