TORREYA 
oy ot May-June, 1931 No. 4 
Inheritance and Chromosome Number in the Gladiolus 
i ForMAN T. McLean 
The garden hybrid gladiolus has probably a greater capacity 
for variation in its inheritance than any other cultivated plant. 
This would be expected from its ancestry, for it is derived from 
at least ten, probably more, entirely distinct species. Both cyto- 
logical studies and breeding experiments give ample evidence of 
capacity for wide variability. 
Observations of groups of seedlings of known and controlled 
parentage show that the following characteristics can be inde- 
pendently inherited: hooded or open bloom; with or without yel- 
low, or red, violet or white color respectively in any combination ; 
the color clear, or veined ; or dark-flaked ; throat yellow ; blotched ; 
lined; or dotted in any combination; with or without a pale zone 
around the throat ; segments ruffled or plain; pointed or rounded 
ups; flower spikes stout or slender; with opposite or secund ar- 
rangement ; close or wide spacing of blooms; few or many open at 
once; branched or simple; leaves bright or grayish green; and so 
forth through many other traits. 
All of these varied traits can be directly traced to the differ- 
ent parent species: red-and-yellow flaked G. psittacinus with yel- 
low throat; opposite-flowered white G. oppositiflorus with dark 
lined throat; purple-throated yellow G. purpureo-auratus, V10- 
let-tinted, dark-throated G. papilio; wide-open, white, dark lined 
: floribundus, often somewhat ruffled; reflexed, wide-flowered 
Scarlet G. Saundersii with red-spotted white throat; wide-open, 
rounded G. cruentus, blood red with dark blotch and white outer 
Surrounding zone to the throat; G. dracocephalus, small hooded 
Purple-spotted greenish yellow; deeply hooded yellow drooping 
G, þrimulinus, with its slender growth and long-stalked, soft- 
shelled cormels; and yellow-throated red G. quartinianus, Very 
tall and late-flowering. Some authorities claim still other SPIE 
aS Parents of the garden gladiolus, such as G. cardinalis, G. 
andus, G, tristis, etc. The characters of any one species seem to 
be somewhat linked in the hybrids, so that one can frequently pre- 
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