swingle: a new genus of kumquat oranges 175 



The Hongkong kumquat, which, as ah-eady indicated, is the sole 

 species of the subgenus Protoeitrus, may be described, as follows: 



Fortunella Hindsii (Champ.) Swingle. 



SclerostyUs Hindsii Champ. Hook. Journ. Bot. III. 3: 327. 1851. 



Atalantia Hindsii Oliver ex Benth. Fl. Hongkong. 51. 1861. — 

 Journ. Linn. Soc. 5, Suppl. 2:26. 1861. 



A spiny shrub or small tree; twigs slender, angled when young; 

 leaves oval-elliptical, tapering sharply at both ends, dark green above 

 and faintly venose, paler and venose below; petioles winged, often 

 merging into the lamina of the leaf without a separative joint. Flowers 

 short, broad, not opening very widely; pistil very short; style shorter 

 than the ovary; stigma large, cavernous; ovary 3 or 4-celled; ovules 

 2 in a cell. Fruits small, 1 .5-2 cm. in diameter, subglobose, bright orange 

 red when ripe, the color of a tangerine orange; pulp vesicles very few, 

 small, fusiform; seeds thick, oval or ovate in outline, plump, 9-11 by 

 7-8 by 5-6 mm., pistache green in section. 



Type: Hongkong, R. B. Hinds, without number, 1841; a much 

 branched twig with spines, leaves, fruit pedicels, and one young fruit.^- 

 (Mounted on the same sheet are two twigs collected by Wright.) 

 Herb. Kew. 



The Hongkong wild kumquat grows commonly on the dry hills 

 about Hongkong and on the mainland of China opposite. 



Much other material from Hongkong and some from Kaulung, on 

 the mainland opposite Hongkong, has been examined by the writer 

 in the collections at Kew, British Museum, Museum d'Histoire Natur- 

 elle, Gray Herbarium, and U. S. National Herbarium. Living plants 

 grown in the greenhouses of the Department of Agriculture from seeds 

 from Hongkong have permitted a comparison of this plant at all stages 

 of growth with the other species of Fortunella. 



UTILIZATION OF THE KUMQUATS IN BREEDING NEW TYPES 



OF CITROUS FRUITS 



In connection with the attempt to breed hardy citrous fruits the 

 attention of the writer was directed some years ago to the kumquat 

 oranges, which are particularly remarkable for their very small size 



'2 A label in Bentham's (?) writing, reading "Atalantia monophylla DC. 

 Hong Kong, Hind's, 1841," is pasted across the base of the twic;, which shows it 

 to be without doubt the specimen cited by Bentham (Lond. Journ. Bot. 1: 480- 

 481. 1842). Some of the petioles of this twig exhibit the curious imperfections 

 in the articulation with the blade characteristic of this species; so it is possible 

 to identify this specimen beyond question. 



