For April, 1922 



109 



Factors to Be Considered in Breeding Water Lilies 



GEORGE H. PRING 



BEFORE attempting the systematic breeding of water 

 lilies the gardener should familiarize himself with 

 the many species and present day hybrids. The tax- 

 onomy should likewise be studied so as to be able to dis- 

 tinguish the main groups with their respective sub- 

 groups. If a careful study has been given the breeder will 

 at once be able to place the species under its distinctive 

 section by either stamens, carpellars- styles or leaf char- 

 acters. In most cases the gardener overlooks the botan- 

 ical characteristics as unimportant for the reason that it 

 is too theoretical. Une frequently hears men discredit- 

 ing the use of botany ; however, it is plainly manifested 

 that the present day student in the profession realizes the 

 necessity of the elements of botany in the curriculum of 

 his studies. 



In studving the tax- 

 onomy of the Nymphcra, 

 we find two main groups, 

 Apocarp'uc and Syncarpicc 

 referring to the arrange- 

 ment of the carpels or divi- 

 sion of the seed pod. The 

 first group Apocarphc has 

 the carpels separating one 

 from the other within the 

 ovary, being fused only 

 from the central axis. This 

 fact is easily observed in 

 N. gigantca by making a 

 cross section of the ovary, 

 the walls dividing the 

 ovules can readily be sep- 

 arated. All the species 

 under this main group are 

 of diurnal tiowering habit 

 ranging in color from 

 white, pink to blue. This 

 group is again subdivided 

 into two sections (A) 

 Anccphya which includes 

 but one species, A', gigan- 

 tca. native of Australia and 

 one of the most showy of 

 water lilies and by far the 

 hardest to flower, where 

 tropical Summers are lack- 

 ing. The distinguishing 



features of this sub-s^roup . 



is the absence of carpellary styles, which with otlier 

 species from the innermost corona of the flower 

 indicating the division of the ovary. (B) Brachyceras 

 embracing upwards of fifteen swcies of world-wide dis- 

 tribution 'in the tropics. This sub-group gives us the ma- 

 jority of the dav bloomers frequently met with m aquatic 

 collections as c'apcnsis. Zanziharicnsis. cwniica and hy- 

 brids Whitaker, Pershing, Wilson gigantca. Panania la- 

 cific Castalitioni. Tennsvlvania. Stella Gurney, t. V\ . 

 Ward and William Stone. The distinctive characters are 

 the prominent carpellarv styles of triangular shape form- 

 ing a circle upon the top of the pistil which indicates the 

 number of seed chambers within. The anthers are long, 

 supported upon oval filaments grading down m size to 

 where they resemble the styles. 



Group (2) Syncarpin- is the larger of the main di- 

 visions, including both tropical and temperate species of 

 diurnal and nocturnal flowering habit. The separation 



Mrs. Edzcanls H'hitakt'r. var. ma 

 ofcr one foot in diameter. {N 



from the first is owing to the complete fusion of the car- 

 pels on all sides, whereas the Apocarpice carpels were sep- 

 arated along the side walls. The color of the flowers vary 

 from white, rose to purple or yellow, but no blue. The 

 group is subdivided into three. (A) Castalia in which all 

 the hardy varieties are included ; this, in itself is sufficient 

 for the la\man to be able to place in its respective section. 

 The botanical characters are the petaloid stamens, being 

 strap-shaped, terminating with short anthers, flowers 

 usually floating. Rhizomes, somewdiat dififerent from all 

 other species in not being protected against drought but 

 lying dormant throughout the Winter. There are seven 

 species found in all of the North Temperate Zone, except 

 the Pacific Slope of North America. (B) Lotos, this 

 familiar group presents the beautiful night bloomers of 



our gardens. Conrad rec- 

 ognizes four species, lotos, 

 rubra, Zcnkcri and piibcs- 

 cciis. The latter two I 

 have not seen in cultivation. 

 All the present day hybrids, 

 including many forms, are 

 derived from the original 

 parentage lotcs and rubra. 

 This section is easily rec- 

 ognized by the vegetative 

 characters as the prominent 

 venation on the underside 

 and prominently toothed 

 edges of the leaves. In 

 the seedling stage it is pos- 

 sible to place them by the 

 elongated saggitate sub- 

 merged leaves. Other fac- 

 tors are the large cari^ellary 

 styles w h i c h are strap- 

 shaped and bend over the 

 pistil, the stamens are 

 linear, wedge-shaped and 

 rounded at the apex, not 

 pointed as with other types. 

 (C) Hydrocallis like the 

 previous group have noc- 

 turnal flowers but instead 

 of being supported upon 

 stout peduncles they are 

 floating. The notable fea- 

 tures of this section are 

 the nmisually large club-shaped styles and the long hairs 

 attached to the seeds. I have not seen any species under 

 cultivation, but I understand one species N. Rudgiana 

 was formally under cultivation in the Oaks Ames collec- 

 tion. Seeds of the group are used as food by the South 

 Americans. It is manifested by these varied descrintions 

 that there are several parts of the floral envelope, either 

 of which may be used to classify the group or sub-group. 

 The stamens are the easiest to use for placing the respec- 

 tive sections. 



After studying the genus so as to become acquainted 

 with the type material to-work with, the hybridist will de- 

 cide to exert his energies in crossing night and day 

 bloomers, with the object in mind of a perpetual blooming 

 water lily. In reviewing the work of former hybridists 

 the amateur will probably be somewhat enthused by Mar- 

 liac's assertion that the red color in his noteworthy hybrids 

 of hardy lilies was obtained from the lotos group iV. 



nnorata, presenting; four ttoii'ers 

 . A. G. gold medal zvater lily.) 



