酸橙Citrus aurantium Linn.

别名：sour orange;臭橙;江枳壳;枸头橙;钩头橙;代代花;代代;大麦橙;臭橘子;香橙;来母;臭柑子;川枳壳;玳玳花;泡柑;酸黄菓;皱皮柑;枳实;枳壳;香圆;香团;酸栾;酸柑子;皮头橙;苦橙;

科名：芸香科 Rutaceae

属名：柑橘属 Citrus

《中国植物志》第43(2)卷194页
  10. 酸橙
  Citrus aurantium L. Sp. Pl. 2: 782. 1753; Engl. in Nat. Pflanzenfam. 19a: 342, f. 155 A-F. 1931; Swingle in Webb. et Batc. Citrus Indust. 1: 402. 1943, et in Reuth. et al. l. c. 1: 374. 1967; Tanaka, Sp. Probl. Citrus 123. 1954; 中国高等植物图鉴 2: 558. 图2846. 1972; 海南植物志 3: 52. 1974. —— Aurantium acre Mill. Gard. Dict. ed. 8, 1768; Tseng 中国果树 2: 35. 1960. nom. seminud.
  小乔木，枝叶密茂，刺多，徒长枝的刺长达8厘米。叶色浓绿，质地颇厚，翼叶倒卵形，基部狭尖，长1-3厘米，宽0.6-1.5厘米，或个别品种几无翼叶。总状花序有花少数，有时兼有腋生单花，有单性花倾向，即雄蕊发育，雌蕊退化；花蕾椭圆形或近圆球形；花萼5或4浅裂，有时花后增厚，无毛或个别品种被毛；花大小不等，花径2-3.5厘米；雄蕊20-25枚，通常基部合生成多束。果圆球形或扁圆形，果皮稍厚至甚厚，难剥离，橙黄至朱红色，油胞大小不均匀，凹凸不平，果心实或半充实，瓢囊10-13瓣，果肉味酸，有时有苦味或兼有特异气味；种子多且大，常有肋状棱，子叶乳白色，单或多胚。花期4-5月，果期9-12月。
  染色体数X＝9，2n=18。
  秦岭南坡以南各地，通常栽种，有时逸为半野生。
  酸橙被广泛应用作嫁接甜橙和宽皮橘类的砧木。优点是根系发达，树龄长，耐旱、耐寒、抗病力强。品种之一的构头橙兼有耐盐碱土的特性，是浙江省黄岩地区用作嫁接柑橘类的优良砧木。但酸橙的品种品系十分复杂，嫁接后亲和表现差异甚大。据试验报道，代代酸橙、兴山酸橙、江津酸橙都不能用作砧木。▽中药枳实及枳壳，有用黄皮酸橙的果制成，以湖南的最为大宗，次为湖北和江西，其他省区也有少量。▽据实验报道。酸橙枳实有持久的升压作用，还有改善微循环作用，适用于治疗休克。国产酸橙实含synephrine和N-methyl tyramine。前者在红皮橘类的果皮及叶片也曾分离出来。▽酸橙的叶和花含芳香油量约0.2-0.4%，果皮含油量约1.5-2%。油的成分有： nerol、nerobdol、linalool等约20类。又含多种黄酮甙类；aurantiamarin、auranetin、hesperidine等。果肉主要含柠檬酸、维生素C。有特殊异味的可能是含有putrescine。国外产的酸橙品种尚含dipentene、sabinene、myrcene以及喹啉类生物碱。种子含脂肪油：以油酸、亚油酸及棕榈酸为主，硬脂酸少量。
  酸橙大抵可分为黄皮酸橙与红皮酸橙两大类。尚有一些变异型与自然杂交种。▽黄皮酸橙类性状较原始，果皮较厚，表面粗糙或有皱劈，色淡黄或橙黄，含油较多，香气较浓，剥离较困难，果肉味甚酸，常兼有苦味或特异气味。长江以南、五岭以北较多栽种，在山地偶有半野生的。这一类的代表有：▽(1) 黄皮酸橙 Huangpi Suan Cheng,又称酸柑子、臭柑子、药橘子。主产湖北西部、湖南、贵州东部。湖南的主产区在沅江一带及西部各地。本地区内的中药枳实及枳壳即用其果制成。果肉甚酸，瓢囊有苦味；种子多且大。
  (2) 红皮酸橙 Hongpi Suan Cheng 的果皮橙红色，皮较薄，稍粗糙，较易剥离，果较大，果心近于中空，果肉味酸，有时带苦味。这一类的代表有：
  (3) 酸橙的杂交种颇多，有酸橙与甜橙，酸橙与柚，酸橙与宽皮橘类等多种杂交，较常见的有：

《Flora of China》 Vol. 11 (2008)
Citrus ×aurantium  Linnaeus
酸橙   suan cheng
Aurantium ×acre Miller; A. ×corniculatum Miller; A. ×distortum Miller; A. ×humile Miller; A. ×myrtifolium Descourtilz; A. ×sinense Miller; A. ×vulgare (Risso) M. Gómez; Citrus ×amara Link; C. ×aurantium subsp. amara Engler; C. ×aurantium var. bigaradia (Loiseleur) Brandis; C. ×aurantium var. crassa Risso; C. ×aurantium var. daidai Makino; C. ×aurantium var. dulcis Hayne; C. ×aurantium var. fetifera Risso; C. ×aurantium var. lusitanica Risso; C. ×aurantium var. myrtifolia Ker Gawler; C. ×aurantium subf. nobilis (Loureiro) Hiroe; C. ×aurantium var. sanguinea Engler; C. ×aurantium subf. sinensis (Linnaeus) Hiroe; C. ×aurantium subsp. sinensis (Linnaeus) Engler; C. ×aurantium var. sinensis Linnaeus; C. ×aurantium subsp. suntara Engler; C. ×aurantium var. vulgaris (Risso) Risso & Poiteau; C. ×aurata Risso; C. ×bigaradia Loiseleur; C. ×changshan-huyou Y. B. Chang; C. ×communis Poiteau & Turpin; C. decumana (Linnaeus) Linnaeus var. paradisi (Macfadyen) H. H. A. Nicholls; C. ×dulcis Persoon; C. ×florida Salisbury; C. ×humilis (Miller) Poiret; C. maxima (Burman) Merrill var. uvacarpa Merrill; C. ×myrtifolia (Ker Gawler) Rafinesque; C. ×paradisi Macfadyen; C. ×sinensis (Linnaeus) Osbeck; C. ×sinensis var. brassiliensis Tanaka; C. ×sinensis subsp. crassa (Risso) Rivera et al.; C. ×sinensis subsp. fetifera (Risso) Rivera et al.; C. ×sinensis subsp. lusitanica (Risso) Rivera et al.; C. ×sinensis var. sanguinea (En gler) Engler; C. ×sinensis var. sekkan Hayata; C. ×sinensis subsp. suntara (Engler) Engler; C. ×taiwanica Tanaka & Shimada; C. ×tangelo Ingram & H. E. Moore; C. ×vulgaris Risso.
Small trees. Branches with spines up to ca. 8 cm. Petiole obovate, 1-3 × 0.6-1.5 cm, base narrow; leaf blades dark green, thick. Inflorescences racemes, with few flowers or flowers solitary. Flowers perfect or male by ± complete abortion of pistil; buds ellipsoid to subglobose. Calyx lobes 4 or 5. Petals 2-3.5 mm in diam. Stamens 20-25, usually basally connate into bundles. Fruit orange to reddish, globose to oblate, surface coarse; pericarp thick, sometimes difficult to remove; sarcocarp with 10-13 segments, acidic and sweet or sometimes bitter. Seeds numerous, large, with ridges; embryo(s) solitary to numerous; cotyledons milky white. Fl. Apr-May, fr. Sep-Dec. 2n = 18.
Cultivated and sometimes naturalized in most of China S of the Qin Ling.
Oranges and grapefruit are Citrus maxima × C. reticulata and the backcrosses with the parental species. Many of these hybrids arose in China, although others were synthesized, especially in the U.S.A., and introduced in China. The cultivars can be arranged in groups: Sour Orange Group (the sour or bitter orange most like the original cross), Sweet Orange Group (the commercially most important being backcrosses with C. reticulata ), and Grapefruit Group (representing backcrosses with C. maxima and first being made in the Caribbean).

Sweet Orange Group
Petiole long and narrow; leaf blade ovate, ovate-elliptic, or rarely lanceolate, 6-10 × 3-5 cm or larger. Calyx lobes 3-5. Petals white or rarely purplish, 1.2-1.5 cm. Style stout; stigma large. Fruit orangish yellow to orangish red, globose, depressed globose, or ellipsoid; sarcocarp with 9-12 segments, yellow, orange, or purplish, sweet or slightly acidic. Seeds few or absent; seed coat slightly ridged; embryos numerous; cotyledons milky white. Fl. Mar-Jun, fr. Oct-Dec but some cultivars Feb-Apr. 2n = 18, 27, 36, 45.

Below 1500 m. Cultivated S of the Qin Ling, as far NW as SE Gansu and as far SW as SE Xizang.

Grapefruit Group
Branches glabrous. Leaves similar to those of Citrus maxima but leaf blade smaller and narrower, midvein ciliate. Flowers smaller than those of C. maxima. Calyx lobes glabrous. Fruit yellow, depressed globose to globose, smaller than those of C. maxima; pericarp thin; sarcocarp with 12-15 segments, yellowish white or pink, tender, juicy, slightly fragrant and acidic. Seeds few or absent; embryos numerous. Fr. Oct-Nov. 2n = 18, 20, 27, 36.