生活型

herb

形態特徵

• Annual or perennial, stranded or floating aquatic herbs. Rhizoids present or absent, filiform, branched. Stolons filiform, much branched and often mat-forming.
• Leaves numerous on stolons, 0.5–1.5 cm long, primary segments (1) 2, unbranched or sparsely dichotomously branched into 3–8 ultimate segments; ultimate segments capillary, slightly flattened, margins entire or sparsely denticulate, apex and teeth setulose. Traps lateral on leaf segments, ovoid, 1–2.5 mm long, stalked; mouth lateral, with 2 setiform, branched appendages and shorter setae.
• Inflorescence erect, 2–15 cm long, 1–3(–6)-flowered; dorsal, peduncle terete, 0.3–0.5 mm thick, glabrous; scale 1, similar to the bracts; bracts basifixed, semicircular, ca. 1 mm long, minutely glandular, apex truncate or obscurely dentate; bracteoles absent; pedicels erect or spreading, filiform, 2–12 mm long. Calyx lobes subequal, broadly ovate or circular, 1.5–2 mm long, apex rounded. Corolla yellow, 4–8 mm long; upper lip broadly ovate or subcircular, ca. twice as long as upper calyx lobe, apex obscurely 3-lobed; lower lip slightly smaller, base with a prominent, bilobed swelling, apex rounded; palate densely pubescent; spur narrowly conical or cylindrical from a conical base, apex obtuse, shorter or longer than lower lip, distal part sparsely stipitate-glandular. Filaments curved, 1–1.5 mm long; anther thecae confluent. Ovary globose; style distinct; lower lip of stigma transversely elliptic, upper lip obsolete.
• Capsule globose, 2–3 mm in diam., bivalvate. Seeds lenticular, 0.8–1 mm in diam., margin broadly winged, wing shallowly and irregularly dentate; testa with small, reticulate prominences.

物候

Flowering April to November, fruiting May to December.

分布

• 台灣 : in shallow, still and slowly flowing water, and in pools, lakes, bogs, swamps, marshes and rice fields at low to middle elevations.
• 世界 : Pantropical, extending into southern Canada, Spain, Portugal, Israel, China and Japan and southward to Argentina, southern Africa, Australia and New Zealand.

引證標本

TAIPEI: Chili, Yoshida 5; Musha, Chuang 3088; Neihu, Nakamura 4066; Nankang, Peng 9760; Peitou, Simada s. n. 1914. TAOYUAN: Yangmei, Peng 11123; Patei, Chuang 4611; Tachuwei, Sasaki s. n. 1909. HSINCHU: Chingtsaohu, Kuo s. n. 1966. NANTOU: Puli, Kawakami s. n. 1910. PINGTUNG: Nanjenshan, Koyama & Kao 8919.

參考文獻

• LI, Zhen-Yu. 1998. Flora of Taiwan, second edition 4: 724. (Fl. Taiwan 2nd edit.)