Yama-mikan sour orange

Citrus intermedia

CRC 3474

PI 539255

Photos by David Karp and Toni Siebert, CVC,  3/3/2008. Photo rights.

Source: Received as seed from Okitsu, Shizuoka Prefecture, Japan, via W.P. Bitters, 1963. Open pollinated seedling.

Parentage/origins: Parents unknown.

Rootstocks of accession: Carrizo citrange, C-35 citrange

Season of ripeness at Riverside: January to March

Notes and observations:

T. Tanaka: Polyembryonic. In CITROLOGIA, pg 52, Univ. Osaka, Japan, 1961: Referred to as Yama mikan or "mountain citrus". Origin is unknown but it is undoubtedly a cultivar related to the shaddock- as its true habit and petiole wings of the foliage indicate.

1963, WPB: From W.P. Bitters' 1963 trip to Japan: A large fruit, wide 9.5 cm, height 7.9 cm, similar to Natsudaidai in size, shape & color, oblate to slightly oblique shaped, stem end flat, slightly bumpy, rind 7.8 mm, very hollow center, 25-30 seeds, fruit is acid, low solids, leaves large, acuinate tips, petiole average, large wings on petiole (like grapefruit).

2/26/1988, EMN: WPB description above is good. Fruit is very juicy, close to edible but a bit too acid.

3/3/2008, DK & TS: Listed among the miscellaneous citrus species on the CVC holdings appendix [http://www.grcp.ucdavis.edu/publications/doc22/Appx.pdf], but GRIN posits partial sour orange parentage.
Slightly necked, grapefruit-colored fruit; rind 1 cm thick; large oil glands, marked aroma of sweet orange; light orange flesh, tender, juicy, fairly sweet and pleasant; fairly seedy. Large tree. Seems like a hybrid of sweet orange and grapefruit, by the fruit.

Availability: Not commercially available in California.

USDA Germplasm Resources Information Network page for Yama mikan sour orange