VOLUME LXxXIII NUMBER 1 
THE 
BOTANICAL GAZETTE 
fanuary 1922 
N ON SYMBIOTIC GERMINATION OF ORCHID SEEDS 
Lewis KNUDSON 
(WITH THREE FIGURES) 
The germination of orchid seeds for a long time has been recog- 
nized as difficult and generally uncertain of attainment. Practical 
orchid growers for years have attempted to find a method which 
will insure germination. They meet with success at times, but 
fail utterly on a second attempt with the same method. More- 
over, two sowings made at the same time and under apparently 
identical conditions may result in germination in the one case and 
failure in the other. There are growers in England, France, and 
also the United States who, if one may believe reports, are con- 
sistently successful in germinating the seeds of the commercially 
important orchids. The grower, however, is naturally unwilling 
to part with the details of his method. From the scientific aspect 
it is doubtful whether he can explain the cause of his success. 
Generally speaking it may be stated that practical orchid growers 
have not yet solved the problem of producing orchid plants from 
seeds. 
The difficulty of germinating seeds of orchids is due in part to 
inherent causes, but undoubtedly is due also to environmental 
factors. The extremely small size of the embryo renders it liable 
to death if it becomes desiccated. Generally the seeds are sown 
on a substratum rich in organic matter, such as sawdust, leaf 
mold, wood or bark, peat, sphagnum, or mixtures of the two last- 
named substances. These substances are favorable for the growth 
I 
