作者于2024年5月(
https://ppbc.iplant.cn/tu/20896256)在西藏定结开展野外植物调查期间,在高山湿润苔藓丛中发现了一种体态极小、形态特征独特的毛茛科植物。经查阅相关文献和标本,作者确认该植物为单型属单性鸦跖花属(
Paroxygraphis W.W. Smith)的单性鸦跖花(
P.sikkimensis W.W. Smith)(
图1)。为进一步获取该物种的详细资料,2025年7月作者再次前往西藏定结,采集了该种的植物标本,并拍摄了详细的野外活植物彩色照片(图
2-
5)。在后续的野外植物调查中,作者发现该种在西藏吉隆和亚东一带亦有分布。由于单性鸦跖花属在我国为首次记录,特此报道。
单性鸦跖花属
Paroxygraphis W.W. Smith in Rec. Bot. Surv. India 4: 344. 1913; Hara, En. Fl. Pl. Nepal 2: 18. 1979; Grierson in Fl. Bhutan 1(2): 305. 1984; Tamura in Nat. Pflanzenfam., Band 17 a IV: 408. 1995. Type: P.sikkimensis W.W. Smith
该属与鸦跖花属相似,但植株更小,雌雄异株,花瓣通常5枚。
This genus is similar to Oxygraphis, but the plants are smaller, dioecious, and usually have five petals.
单性鸦跖花
单性鸦跖花属
(Paroxygraphissikkimensis W.W. Smith) in Rec. Bot. Surv. India 4: 344. 1913; Hara, En. Fl. Pl. Nepal 2: 18. 1979; Grierson in Fl. Bhutan 1(2): 305. 1984; Naithani in Fl. Pl. India, Nepal and Bhutan 13. 1990; Tamura in Nat. Pflanzenfam., Band 17 a IV: 408. 1995. Figs.
1-
5.
Type: India, Sikkim, near Changu bungalow, in the Dikchu valley, in the Chola Range below the Tanka La pass,
W.W. Smith 3204 (lectotype K000692711!, designated here; isolectotype E00438614!). Remaining syntypes: near Changu bungalow, in the Dikchu valley, in the Chola Range below the Tanka La pass,
W.W. Smith 3318 (not seen),
3359 (K!),
3635 (not seen),
3864 (E01135522!), and in Jongri,
G.A. Gammie 139 (not seen),
G. Watt s.n. (K000692712!), in the wetter mountain ranges, at an altitude of 12,000 to 14,000 feet.
Fig. 1.
多年生矮小草本,全株无毛,雌雄异株。须根3 ~ 5条簇生,基部增粗呈纺锤形。根状茎不发达。叶3 ~ 8枚基生;叶片近卵形或宽卵形,革质,宽约2 mm,长约3 mm,正面绿色,背面浅绿色,基部楔形至圆或近浅心形, 全缘;叶柄长1 ~ 2 cm,基部扩大成膜质鞘,枯叶鞘宿存。单花,顶生,直立,单性,直径约0.5 cm,宽杯状;花葶高1 ~ 2 cm。萼片5枚,果期宿存,卵圆形至宽卵圆形,长2.8 ~ 3 mm,宽2.6 ~ 2.8 mm,两面绿色,边缘带紫色,与花瓣等长或稍短。花瓣淡黄色,常5枚,稀6 ~ 8枚,披针形或匙形,长2.8 ~ 3.2 mm,宽约1 mm,爪长0.6 ~ 0.8 mm,基部具明显凹陷的蜜腺。雌花:雌蕊15-25枚,倒卵球形,长约1 mm,花柱长约0.5 mm。雄花:雄蕊6 ~ 12枚,花丝黄色,长0.7 ~ 1 mm,花药紫色,长约0.5 mm。瘦果绿色,有时带棕色,宽倒卵球形,10 ~ 25枚,长约2 mm,宽约1 mm,有3条明显的纵肋,花柱直,三角形,棕色,长约0.5 mm。花托果期不膨大。花期5月,果期6 ~ 7月。
Small dioccious perennials, glabrous. Roots fasciculate, thick. Rhizome not well-developed, collar covered with vestiges of old leaf-sheaths. Stem scapose 1, 1 ~ 2 cm tall. Basal leaves 3 ~ 8, rosulate; blades ovate or broadly ovate, coriaceous, ca. 2 mm broad, ca. 3 mm long, green on adaxial side, pale green on abaxial side, broadly cuneate, round, truncate or slightly cordate at the base, entire; petioles 1 ~ 2 cm long, dilated downward into a membranaceous sheath. Flower solitary, terminal, erect, unisexual, ca. 5 mm in diameter, broadly cup-shaped. Sepals 5, persistent, elliptic to broadly elliptic, 2.8 ~ 3 mm long, 2.6 ~ 2.8 mm broad, green or purplish, slightly enlarged after anthesis, as long as or slightly shorter than petals. Petals pale yellow, usually 5, rarely 6 ~ 8, lanceolate or spatulate, 2.8 ~ 3.2 mm long, ca. 1 mm broad, claw 0.6 ~ 0.8 mm long, with a nectary sunken at the base of limb. In female flowers: carpels 15 ~ 25, obovoid, ca. 1 mm long, style ca. 0.5 mm long. In male flowers: stamens 6 ~ 12, filaments pale yellow, filiform, 0.7 ~ 1 mm long, anthers purple, elliptic, ca. 0.5 mm long. Achenes green or brownish, broadly obovoid, 10 ~ 25, ca. 2 mm long, ca. 1 mm broad, hardly compressed, pericarp thin, with a longitudinal unbranched vein on each side, costate along the vein, beaks straight, brown, triangular, ca. 0.5 mm long. Receptacle hardly enlarged after anthesis..
物候期(Phenology):花期5月;果期6月至7月。
分布与生境(Distribution and habitat):单性鸦跖花主要分布于东喜马拉雅地区,包括不丹、尼泊尔、印度和中国(西藏;Fig. 6);生于高山崖壁湿润苔藓丛中或高山湿润草甸上,海拔3 600 ~ 4 900 m。
标本引证(Additional specimens examined:):中国(China):西藏(Xizang),定结(Dingjie),QTP-LuoJ-2296(XZE),QTP-LuoJ-2297(XZE);吉隆(Jilong),QTP-LuoJ-2570(XZE);亚东(Yadong),QTP-LuoJ-2568(XZE)。Bhutan:Phajuelin,R.E. Cooper, A.K. Bulley & B. L. Cheshire 3899(E00168867)。India:Sikkim,A.G.S.E.S. 53(K),221(K),G.H. Caves.n.(E01135525;E01135526;E01135528),R.E. Cooper & B. L. Cheshire 34(E01135527),R. Lepeha 863(E01135524),884(E01135521),D.G. Long et al. 313(E01135523;E00850180)。Nepal:Koshi,R.J.D. McBeath 2503(E00985173),H. Ohba et al. 9110246(E00146016)。
单性鸦跖花属由
Smith & Cave(1913)建立,仅含单性鸦跖花一种,分布于喜马拉雅东部(印度锡金)。
Smith & Cave(1913)认为该属植物体态较小,与鸦跖花属(
Oxygraphidis L.)相似,但单性鸦跖花属为雌雄异株且花的结构不同而与鸦跖花属不同。在宿存萼片以及花瓣五枚等特征上则与
Hamadryas Comm. ex Juss有显著区别,因此将它建立为单型属。该属自发表以来被一直被承认为独立的属(
Hara,1979;Grierson,1984;Naithani,1990;Tamura,1995),并在喜马拉雅东部的尼泊尔、不丹等与印度锡金临近地区被陆续发现和采集。单性鸦跖花属独特的形态对毛茛科的系统学研究具有一定价值,后续需进一步对其展开系统发育研究。
在原白中,
Smith & Cave(1913)引证了多号标本(包括
W.W. Smith 3204,
3318,
3359,
3635,
3864,
G.A. Gammie 139和
G. Watt s.n.)作为单性鸦跖花的模式。根据现行“国际藻类、真菌和植物命名法规(深圳法规)”(
Turland et al.,2018)的Art. 9.3和Art. 9.11以及
McNeill (2014)关于模式标本的讨论,它们属于合模式,故需为单性鸦跖花指定后选模式。在这些合模式标本中,我们发现藏于邱园标本馆(K)的
W.W. Smith 3204(K000692711)标本保存较好,其上植株清晰可见,且保存了雌株和雄株的完整个体。因此,我们将其指定为单性鸦跖花的后选模式。