白頭樹
| 白頭樹 |
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中文學名:白頭樹 拉丁學名:Garuga forrestii W. W. Smith 界:植物界 門:被子葉植物門 綱:雙子葉植物綱 亞 綱:原始花被亞綱 目:芸香目 亞 目:芸香亞目 科:橄欖科 屬:嘉欖屬 種:白頭樹 |
白頭樹是一種落葉喬木，高10—25米，幼枝密被柔毛，老枝無毛，紫褐色，有縱條紋及明顯的葉痕。 [1]
目錄
白頭樹形態特徵
小葉近無柄，披針形至橢圓狀長圓形，頂端漸尖，基部圓形或闊楔形，具淺齒，有小托葉。最下一對小葉小，長約1厘米，常早落 ；中間一對長7—12厘米，寬2—4厘米，側脈10—16對；頂生小葉長5—7厘米，具柄，柄長約1.5厘米。圓錐花序側生和腋生，常多數聚集於近小枝頂部，長14—25（—35）厘米，多次分枝，花軸及分枝纖細，密被直立的柔毛。
花白色，長約3毫米，花托杯狀，外被絨毛；萼片近鑽形，長0.2厘米，兩面被毛；花瓣卵形，長約3毫米，外被絨毛；雄蕊近等長；子房無柄，球形，和花柱被疏柔毛，柱頭5淺裂。果序有許多不結實的線形花梗。
果近卵形，一側腫脹，橫切面多少呈鈍三角形，長0.7—1厘米，直徑0.6—0.8厘米，兩端尖，先端具喙而偏斜一側，基部有宿存的淺杯狀花萼。花期4月，果期5—11月。
Trees, 10-15(-20) m tall. Branchlets densely pubescent when young, glabrescent, purple-brown, longitudinally striped and conspicuously lenticellate. Leaflets 11-19, nearly without petiolules; blades lanceolate or elliptic-oblong, densely pubescent when young, glabrescent, base rounded or broadly cuneate, margin shallowly serrate, apex acuminate, lowest pairs small, ca. 1 cm, often early deciduous, middle pairs 7-12 × 2-4 cm, with lateral veins 10-16 pairs, terminal leaflet 5-7 cm, with petiolule ca. 15 mm. Panicles 14-25(-35) cm, axillary or lateral, usually crowded toward ends of branchlets, multibranched; rachis and branches slender, densely tomentose. Flowers white, ca. 3 mm; receptacle cup-shaped, abaxially tomentose. Sepals nearly subulate, ca. 2 mm, hairy on both surfaces. Petals ovate, ca. 3 mm, abaxially tomentose. Stamens nearly equal. Ovary sessile, globose; style sparsely pubescent; stigma shallowly 5-lobed. Infructescence with many linear pedicels without fruits. Drupe nearly ovoid, one side dilated, 7-10 × 6-8 mm, ± obtusely deltoid in cross section, attenuate at both ends, apex with a point, base with persistent shallowly cupular calyx. Fl. Apr, fr. May-Nov.
Garuga forrestii W. W. Smith in Not. Bot. Gard. Edinb. 13: 162. 1921; Hand. -Maza. Symb. Sin. 7:631. 1933, Kalkm. in Blumea 7 (2): 461, fig. 2. 1953; 雲南植物志1: 461, 圖版45: 10-14. 1977; 雲南種子植物名錄, 上冊826. 1984.——G. yunnanensis Hu in Bull. Fan Mem. Inst. Biol. Bot. ser. 7: 212. 1936.