Emilia × latens

Wang, Jen-Yu & Wang, Jenn-Che, 2018, Emerging natural hybrid between Invasive Species and Native Congener of Emilia (Asteraceae) Found in Northern Taiwan, Phytotaxa 382 (2), pp. 204-212 : 207-209

Emilia × latens J.-Y. Wang & J.-C. Wang hybr. nov. ( Figs. 1 , 5 , 6 )

( Emilia praetermissa × Emilia sonchifolia var. javanica )

Common name: Puffy tasselflower; ÊẼküḍ

Diagnosis: the hybrid is morphologically intermediate between E. praetermissa and E. sonchifolia var. javanica . It differs from E. praetermissa by having pink corolla and from E. sonchifolia var. javanica by yellow pollen grains. The involucre is sparsely pubescent with the density of trichomes intermediate between the putative parents.

Type:— TAIWAN. Taipei: Da’an Park, near Xinsheng South Road, 16 m elevation, 1 October 2016, J.Y. Wang 619 (holotype TNU!).

Description: —Perennial herbs, 0.3 to 1.2 m tall, erect to ascending. Taproot with some purple pigment on the surface. Stems erect to ascending, ca. 5 mm in diameter, green with purplish bands or patches, villous. Leaves alternate, sessile, herbaceous, slightly pubescent, green adaxially, purple abaxially; axillary buds and young leaves densely pubescent; lower leaves spatulate to lyrate, with acute apex and truncate base, margin entire to slightly dentate, 3–7 cm long, 2–3 cm wide (at the widest part); upper leaves lyrate to sagittate, with acute apex and auriculate-clasping base, margin dentate, 3–5 cm long (from leaf-stem junction to apex), 1–3 cm wide (at the widest part). Capitula discoid, 2 to 10 arranged in loose corymbs; peduncle 10–16 cm long; pedicel 1.5–4 cm long; capitula 1.2–1.5 cm long, 1–1.2 cm wide when fully blooming; in“v”olucre tubular, green, pubescent, 9.5–12.5 mm long, 3–4 mm wide, folded reversely and split when fruits are mature; involucral bracts ca. 12, trianglular, green with brown margin, ca. 2 mm long, 0.5–1 mm wide at base; corolla pink, ca. 10 mm long, protruding out of the incolucre ca. 2–3 mm; corolla lobe 1.6–1.75 mm long; stamens dark pink; pollen yellow, sticky; style ca. 11 mm long, with 2 branches ca. 1.35 mm long, white but pigmented at the branches; stigma pink with yellow tone, with 3 brush-like appendages at the tip; achenes aborted and shrunk, pappus with ca. 90–110 fine bristles.

Etymology:—Because the hybrid is not distinguishable from the parents by only vegetative morphology and it always found mixed with the parents, we give the name, “ latens ”, meaning “hidden”.

Habitat and distribution:—Roadside, grassland, waste land, garden. Northern Taiwan, mainly in Taipei urban at elevations below 350 m. To date, the hybrids are found in human-disturbed places, mainly in Taipei City. The hybrids may be potentially found in all the places where the parent species grow together.

Additional specimen examined (paratypes): — TAIWAN. Taipei City: Wenshan District, National Taiwan Normal University ( Gongguan campus), 3 Dec 2016, J.- Y. Wang 639 ( TAI) ; Nangang District, Academia Sinica , J.- Y. Wang 617 ( TAIF) ; Taipei Botanical Garden , 9 Feb 2017, J.- Y. Wang 646 ( HAST) ; Beitou District, Shamao Road , 31 Jan 2016, J.- Y. Wang 612 ( TNU) ; Zhongzheng Dist., Hangzhou South Road & Roosevelt Road intersection, 3 Mar 2017, J.- Y. Wang 655 ( TNU) ; Nanhai Road & Nanchang Road (Special Police Sixth Headquarters, National Police Agency, Ministry of the Interior ), 9 Feb 2017, J.- Y. Wang 642 ( TNU) ; Daan District, Daan Forest Park, 18 Oct 2015, J.- Y. Wang 585 ( TNU). New Taipei City: Zhonghe District , Zhanghe Junior High School , 28 Feb 2017, J.- Y. Wang 649 ( TNU) .

Figures

FIGURE 1. Morphology of capitula and florets of E. praetermissa (E. p.), E. sonchifolia var. javanica (E. s. j.) and E. ×latens (Hybrid). (A) Lateral view of the capitula, the florets of E. praetermissa and E. ×latens extend more outwardly, which makes the capitula looks more open. (B) Top view. (C) Dissected involucre, showing the intermediate trichome density in E. ×latens. (D) Florets, showing corolla lobes, color of corolla and stigma. (Photographer: WANG, JEN-YU).

FIGURE 5. Color photos of E. ×latens in the field. (Photographer: WANG, JEN-YU).

FIGURE 6. (A) Morphology of styles of E. praetermissa (E.p.), E.× latens (Hybrid) and E.sonchifolia var. javanica (E.s. j.) respectively. The ovary has been removed. (B, C, D) A close-up view of the style branches and stigma of E. praetermissa, E. ×latens and E. sonchifolia var. javanica respectively. The brownish stains result from the damage of forceps when we isolated the style even very carefully. (E, F, G) The morphology of stigma under 100× field of microscope, in the same order as prior. (Photographer: WANG, JEN-YU).