青城山鳳仙花：中國鳳仙花屬一獨特新種及其系統關係

Impatiens qingchengshanica (Balsaminaceae), A Unique New Species from China and Its Phylogenetic Position

袁永明(Yong-Ming Yuan) ； 宋頤(Yi Song) ； 葛學軍(Xue-Jun Ge)

《Botanical Studies》 52卷2期 (2011/04) Pp. 225-230

摘要

本文描述了中國四川青城山地區所特產的鳳仙花屬一獨特新種：青城山鳳仙花(Impatiens qingchengshanica Y.-M. Yuan, Y. Song & X.-J. Ge)。該新種生長在青城山地區海拔700-1,400米的闊葉林下及山谷陰濕處。青城山鳳仙花具有獨特的節結狀根狀莖而與鳳仙花屬其他所有已知種類不同。它在花的形態方面與產于廣西與雲南東南部及越南北部的棒鳳仙花(I. clavigera Hook. f.)相似，但它的葉片長圓形、橢圓形或闊橢圓形；花色豔麗、粉紅色；下萼片漏斗狀，急狹成鑽形、通常直伸的距；左右兩側的側生合生花瓣大小和形態不等，因此其花整體偏斜、不對稱；而棒鳳仙花的葉倒卵狀披針形或倒披針形，花亮黃色，下萼片近囊狀、急狹成細管狀且內彎的距，左右兩側的側生合生花瓣大小和形態基本相等，因此其花整體兩側對稱。青城鳳仙花在莖和葉的形態方面與產於四川峨眉山的峨眉鳳仙花(I. omeiana Hook. f.)及產於湖北西部和四川東部的湖北鳳仙花(I. pritzelii Hook. f.)相似，但在花的整體形態和構造方面明顯不同。峨眉鳳仙花的花黃色或黃白色，下萼片近囊狀或囊狀，漸狹成內彎且很短的距，側生合生花瓣較小、兩側對稱。湖北鳳仙花的花黃色或黃白色，下萼片囊狀或闊囊狀，漸狹成內彎的距, 側生合生花瓣兩側對稱，下裂片長圓形，先端鈍圓。該新種在鳳仙花屬系統發育樹上處於基部位置，因此屬於鳳仙花屬中較原始的類型，在研究該屬植物的進化方面有比較重要的意義。分子系統樹表明，作為地下存儲體官，鳳仙花屬中節結狀或塊莖狀的根狀莖可能經歷了多次獨立起源和平行進化，是對季節性乾旱生境的適應。

關鍵字

青城山鳳仙花 ； 鳳仙花科 ； 新種 ； 進化

並列摘要

Impatiens qingchengshanica Y.-M. Yuan, Y. Song & X.-J. Ge, sp. nov. is described and illustrated. It was collected from a broad-leaved forest on Sichuan Province's Qingcheng Shan, Southwestern China. This species is unique in the genus for its specialized nodular (moniliform) and horizontal rootstock with conspicuously enlarged knots (1-3 cm in diameter) and long (3-5 cm), thin (2-3 mm in diameter) string. It resembles I. clavigera Hook. f. in terms of gross floral morphology. Impatiens qingchengshanica has oblong, elliptic or widely elliptic leaves and showy pink flowers. The lower sepal is funnel-form, ca. 4-4.5 cm deep, abruptly narrowed into a subulate spur ca. 2.5-3 cm long, straight, and only occasionally incurved in young buds. The left and right pairs of the lateral united petals are unequal in size thus the whole flower is oblique and asymmetrical. The lower petals of the lateral united petals are oblong and oblique unlike I. clavigera, which has obovate, lanceolate or oblanceolate leaves and bright yellow flowers. Its lower sepal is subsaccate, 2-3 cm deep, abruptly contracted into a narrow tubular spur which is 5-6 mm long, conspicuously incurved when flowering. The left and right pairs of the lateral united petals are almost equal in size, thus the whole flower is nearly symmetrical. The lower petals of the lateral united petals are dolabriform. The new species is also similar to I. omeiana Hook. f. and I. pritzelii Hook. f. in terms of rhizome, leaf and stem morphology, but the flower shape and bauplan are conspicuously different. Impatiens omeiana has enlarged tuberous rhizomes, yellow or pale yellow flowers with subsaccate to saccate lower sepals that gradually narrow into a short incurved spur, and dolabriform lower petals of the lateral united petals. Impatiens pritzelii has a procumbent tortuous subterranean stem with enlarged nodes, yellow or yellow-white flowers with saccate to widely saccate lower sepals which gradually narrow into a short incurved spur, and oblong or subdolabriform lower petals having a rounded apex. The new species is nested in the basal clade of the phylogentic tree of the genus, and thus represents one of the ancestral forms with important implications for understanding the evolution within the genus. Molecular phylogeny further indicated that nodular (moniliform) and tuberose rootstocks may have undergone multiple independent origins and parallel evolution within the genus adaptive to the seasonal dry habitats of the species.

並列關鍵字

Balsaminaceae ； Evolution ； Impatiens qingchengshanica ； New species