GARDEN GLADIOLI 



Most Common Varieties Are Complex Hybrids Representing a Number of Distinct 



Species — Success Suggests That More Species Should Be Used in the 



Production of New Horticultural Forms of Other Flowers' 



Alfred C. Hottes 



Department of Floricviltvire, Cornell University, Ithaca, N . Y. 



GLADIOLUS offers an excellent 

 example of a genus of plants 

 which has been improved for 

 garden purposes by the incor- 

 poration' of a number of species into 

 more complex multiple hybrids than 

 most of the flowers of the garden. The 

 China aster (Callistephus chinensis), 

 sweet pea (Lathyrus odoratus) peony 

 {Paeonia albiflora) and Boston fern 

 (Nepkrolepis exaltata var. hostoniensis) 

 have been improved solely by the selec- 

 tion of variations and mutations within 

 a single species. Phlox, German iris, 

 larkspur {Delphinium), dahlia, colum.- 

 bine (Aquilegia), begonia and chrysan- 

 themum varieties have arisen from the 

 hybridization of several species. The 

 rose, orchid, pelargonium and gladiolus, 

 however, often have in the make-up of 

 their best varieties three to seven species, 

 each contributing characteristics to the 

 modern degree of perfection. 



The genus Gladiolus consists of ap- 

 proximately 130 species, most of which 

 are natives of South Africa, though 

 several are of European origin. Previ- 

 ous to 1840, only a few forms com- 

 manded any attention horticulturally. 

 One was the hybrid species G. colvillei, 

 a rather dwarf plant with flowers 

 characterized by a white area or lozenge 

 in the throat, bordered by a deep color; 

 a feature inherited directly from its 

 parent, G. cardinalis. G. tristis var. 

 concolor was used as the other parent 

 of G. colvillei. 



Another form was known as G. ramo- 

 sus, a branchy plant which resulted 

 from crossing G. oppositiflorus with 

 various hybrids (now unknown) of 

 G. cardinalis. G. oppositiflorus is a 



1 Address before the twelfth annual meeting of 

 Calif., on August 5, 1915. 



native of Madagascar and Natal, and 

 bears a stem 3 to 6 feet tall which 

 produces large white flowers with char- 

 acteristic amethyst stripes in the throat. 

 Twenty-four or even forty blooms are 

 borne upon the stem, twelve of which 

 are often open at one time. This tall, 

 white, many-flowered species was crossed 

 with G. cardinalis, a bright scarlet 

 and rather dwarf species. The result of 

 this crossing was G. ramosus, at that 

 time thought to be quite admirable. 



In 1837 Beddinghaus, gardener to 

 the Duke of Aremberg, had growing on 

 the estate in Engheim the G. ramosus 

 hybrids, and besides these the Parrot 

 Gladiolus, G. psittacinus. In this the 

 upper segment is scarlet, with deep 

 yellow medial line, and is also spotted 

 with yellow at the base; the lower is 

 rich yellow and scarlet. The plant 

 grows to a height of three feet and is 

 clothed for the most part by the sheath- 

 ing bases of the leaves. 



MYSTERY OF GHENT VARIETY 



The species G. ramosus, G. oppositi- 

 florus, G. cardinalis and G. psittacinus 

 were crossed rather promiscuously. In 

 1841 a form appeared which was thought 

 to be superb. In "Flore des vSerres" 

 was published an account of this new 

 type, and it was said to be a hybrid 

 between G. cardinalis and G. psittacinus. 

 However, Dean Herbert and others, 

 after attempts to cross these latter 

 species, failed and declared that the new 

 hybrid was G. psittacinus and G. 

 oppositiflorus instead. A controversy 

 over the parentage has raged since then, 

 but to the writer the explanation is 

 simple in saying that the new hj^brid 



the American Genetic Association, at Berkeley, 



499 



