Yellow Daylily

Hemerocallis lilioasphodelus was an early introduction to Europe, where it naturalized, and then to North America (W. J. Dress 1955; Hu S. Y. 1968; W. B. Zomlefer 1998). This diploid species escapes only sporadically, unlike the more aggressive H. fulva, with true naturalization frequently questioned (W. B. Zomlefer 1998).

The flowers are steamed and then dried as a traditional food in China.

Plants 5–10 dm; roots enlarged, fibrous. Leaf blade dark green, 5–6.5 dm × 0.8–1.5 cm. Scape closely branched distally, 8–12-flowered, taller than foliage. Flowers often remaining open into night, fragrance strongly sweet, lemony; perianth tube shortly funnelform, 1.5–2.5 cm; tepals uniformly pale to bright lemon yellow, veins parallel; outer tepals 5–7 × 1–1.3 cm, margins smooth; inner tepals 5–7.5 × 1–2 cm, margins smooth; filaments 3–3.5 cm; anthers 2–3 mm; ovary 5–6 mm; style white to yellow, 7–8 cm; pedicel 2–4 mm. Capsules fully developed, oblong-elliptic, (2–)3–4 × (1–)1.5–2 cm. Seeds black, round or angular by compression, 3–5 mm, shiny. 2n = 22.

Plants 70--80 cm tall, deciduous in winter. Roots slightly fleshy or ropelike, sometimes with a swollen, tuberous part. Leaves linear, 20--70 × 0.3--1.2 cm, apex acuminate. Scape generally slightly shorter than leaves, solid; main axis distinct; sterile bracts present. Inflorescence branched; helicoidal cymes 2--4(or 5), 2--4(or 5)-flowered; bracts lanceolate, 2--6(--8) cm × 5--7 mm. Pedicel 1--2 cm. Flowers fragrant, opening in afternoon and lasting 1--3 days, blackish purple or green apically in bud. Perianth lemon-colored; tube 1.5--2.5 cm; segments spreading, 5--7 × 1.3--1.6 cm, inner ones slightly wider than outer. Filaments 5--5.5 cm; anthers yellow, sometimes purple-black adaxially, ca. 8 mm. Capsule ellipsoid, ca. 2.4 × 1.2 cm. Fl. Jun--Aug. 2 n = 22.

introduced; N.B., Ont., Que.; Ark., Conn., Ill., Ind., Ky., Maine, Md., Mass., Mich., Minn., Miss., N.J., N.Y., N.C., Ohio, Okla., Pa., R.I., Texas, Vt., Va., W.Va., Wis.; e Asia; naturalized Europe.

Gansu, Hebei, Heilongjiang, Henan, Jiangsu, Jiangxi, Jilin, Liaoning, Shaanxi, Shandong, Shanxi [Japan, Korea, Mongolia, Russia (Siberia); Europe].

Flowering summer.

Roadsides, waste places, open woods; 0--500m.

Forests, thickets, meadows, grasslands, slopes along valleys; 100--2000 m.

Hemerocallis flava (Linnaeus) Linnaeus

Hemerocallis flava (Linnaeus) Linnaeus; H. lilioasphodelus var. flava Linnaeus.