Himalaiella lushaiensis Y.S. Chen & Q. Yuan, 2014

Chen, You-Sheng & Yuan, Qian, 2014, Himalaiella lushaiensis (Asteraceae), a new species from India, Phytotaxa 173 (4), pp. 293-298 : 293-297

Himalaiella lushaiensis Y.S. Chen & Q. Yuan , sp. nov.

Type:— INDIA. [Mizoram], south of Lushai , open grassland, 1372 m, Febuary 1932, M . L . Werger 422 (holotype K!). Figs. 1 , 2 and 3 ( A & C) .

Annual or biennial herbs. Stem 30–50 cm tall, 3–4 mm in diam., solitary, erect, apically branched, sparsely pubescent. Basal and lower stem leaves petiolate; petiole 2–5 cm long, base sheathed; leaf blade ovate to elliptic, 11–13 × 3.5– 4.5 cm, bipinnately divided, abaxially white, conspicuously veined, arachnoid tomentose, gland-dotted, especially so along the veins, adaxially green, scabrous, sparsely strigose, glandular scabrid; primary segments 8–10 pairs, elliptic, apex obtuse and mucronate; secondary lobes 1–3 pairs, obliquely triangular-ovate, sometimes toothed; upper stem leaves sessile, smaller, blade oblong, pinnatisect to pinnately lobed; lateral segments 4–7 pairs, leaf base enlarged and auriculate. Capitula few, usually in a racemiform synflorescence, pedunculate, peduncles 1–6 cm long. Involucre campanulate, 10–15 mm in diam. Phyllaries in 5–6 rows, arachnoid, gland-dotted; outer phyllaries oblong, 5–6 × 1.3–1.5 mm, leafy, gland-dotted, apex densely hairy, obtuse to acute; middle phyllaries oblong, 6–8 × 1.4–1.5 mm, subcoriaceous, deep-brownish hairy, apex acuminate; inner phyllaries narrowly elliptic-linear, deep-brownish hairy, ca. 10 × 1 mm, apex acuminate ( Fig. 4 ). Receptacle bristles subulate, 4–8 mm long. Corolla purple, 9–10 mm long, gland-dotted, tube 4–5 mm long, limb 6–6.5 mm long, lobes 3–3.5 mm long. Achene brown, ca. 4 × 1.4 mm, 4-angled, glabrous, wrinkled, upper part muricate, apical rim forming a conspicuous truncate crown ( Fig. 3 ). Pappus white, 1- seriate, plumose, ca. 9 mm long, basally connate into a ring.

Distribution and habitat:— Himalaiella lushaiensis is a locally endemic species, currently known only from southern Mizo [Lushai] Hills (western range of the Arakan Mountains between western Myanmar and India), Mizoram State, northeastern India ( Fig. 2 ). It grows in open grasslands at altitudes of 1300–2000 m on the top of the Blue Mountain.

Phenology:—Flowering and fruiting in the dry season from November to February.

Etymology:—The specific epithet “ lushaiensis ” is derived from Lushai [now Mizo] Hills, India, where the type material of this species was collected.

Additional specimen examined (paratype): — INDIA. [Mizoram], south of Lushai, top of the Blue Mountain , open grassland, 1829–1981 m, November 1931, M. L . Werger 376 ( K!) .

Discussion:— Himalaiella lushaiensis is most similar to H. natmataungensis Fujikawa (2012: 168) from Myanmar, but differs by its involucre 10–15 mm in diameter, capitula on erect peduncles and in a racemiform synflorescence, peduncles 1–6 cm long, phyllaries usually oblong, apex obtuse to acute; while H. natmataungensis is distinct by its involucre 3–4.5 mm in diameter, capitula nodding and in a corymbiform synflorescence, peduncles 11–30 cm long, phyllaries usualy linear, apex attenuate or aristate. Himalaiella lushaiensis is also similar to H. foliosa ( Edgeworth 1846: 77) Raab-Straube (2003: 391) in its pinnately divided leaves, rugose and muricate achenes with an irregularly toothed crown ( Fig. 3 ), but differs by the stem nearly unbranched, basal leaves petiolate, unwinged, stem leaves distinctly bipinnately divided, primary segments 8–10 pairs, secondary lobes 1–3 pairs, obliquely triangular-ovate, sometimes toothed, and phyllaries lanceolate, broad. A comparison of H. lushaiensis , H. natmataungensis and H. foliosa is given in Table 1.

To facilitate identification of the 15 species currently included in Himalaiella , we herewith provide a key to them on the basis of a survey of both literature and herbarium specimens.

Key to the species of Himalaiella (with distribution ranges indicated)

1. Basal and lower stem leaves pinnately or bipinnately divided, terminal lobe not much larger than lateral ones..............................2

– Basal and lower stem leaves lyrate pinnately lobed or lyrate pinnately divided, terminal lobe much larger than lateral ones or blade undivided ..................................................................................................................................................................................7

2. Plants almost stemless; capitula few, clustered in center of leaf rosette .............................................................................................. .................................................................................................................... H. yakla [ Bhutan, India (Sikkim), Nepal, China (Tibet)]

– Plants with tall stems; capitula numerous, in a racemiform, paniculiform, or corymbose synflorescence........................................3

3. Leaf blade shallowly lobed or toothed; outer phyllaries herbaceous H. peguensis [ Myanmar, Thailand, China (Guizhou, Yunnan)]

– Leaf blade deeply or shallowly lobed; outer phyllaries coriaceous ...................................................................................................4

4. Leaf blade sinuately lobed, margin mucronate, abaxially glabrous, sessille; capitula in lax terminal corymbs or solitary axillary ... ................................................................................................................................. H. chenopodiifolia [ Afghanistan, NW Pakistan]

– Leaf blade deeply lobed, margin dentate, abaxially white tomentose, petiolate or winged; capitula in sparse racemiform or paniculiform synflorescence ..................................................................................................................................................................5

5. Stem profusely branched; phyllaries linear; basal leaves sessile, bipinnate blade with 2–7 pairs of primary segments, segment margin entire or toothed, but never forming secondary lobes............................................... H. foilosa [NW India, Nepal, Kashmir]

– Stem little branched or unbranched; phyllaries oblong, lanceolate or linear; basal leaves petiolate and unwinged; lower leaves petiolate, bipinnate blade with 9–20 pairs of primary segments and with secondary lobes ..............................................................6

6. Stem little branched; involucre 3–4.5 cm in diameter; capitula nodding; peduncle 11–30 cm long; phyllaries linear, apex attenuate or aristate .................................................................................................................................... H. natmataungensis [ Myanmar]

– Stem nearly unbranched; involucre 1–1.5 cm in diameter; capitula erect; peduncle 1–6 cm long; phyllaries oblong or lanceolate, apex obtuse to acute .................................................................................................................................... H. lushaiensis [NE India]

7. Stem simple, scapiform with reduced leaves; capitulum always solitary; leaf blade adaxially grayish green, arachnoid tomentose. .............................................................................................................................. H. abnormis [NW India, W Nepal, China (Tibet)]

– Stem branched or rarely simple, leafy, not scapiform; capitula numerous or solitary; leaf blade adaxially green, scabrous, strigose, or glabrescent ............................................................................................................................................................................8

8. Receptacle with bristles and long subulate paleae; pappus brown; leaf abaxially glabrous ................................................................ ............................................................................................................ H. auriculata [ Bhutan, India, Nepal, Kashmir, China (Tibet)]

– Receptacle with bristles but without paleae; pappus white or straw-colored; leaf abaxially white hairy or tomentose....................9

9. Plants usually profusely branched, capitula numerous; outer phyllaries with a green, herbaceous appendage...............................10

– Plants fewly branched, with 2–4 capitula; outer phyllaries without appendage, long acuminate ...................................................11

10. Involucre 1–2 cm in diameter; capitula solitary or clustered, subsessile or shortly pedunculate; corolla 1–1.2 cm; pappus 0.8–1 cm .................................. H. nivea [ India, Laos, Myanmar, Nepal, N Thailand, N Vietnam, China (Guizhou, Sichuan, Tibet, Yunnan)]

– Involucre 2–4 cm in diameter; capitula mostly solitary, long pedunculate; corolla 1.5–2 cm; pappus 1.4–1.6 cm ............................ ............................................................ H. deltoidea [ Bhutan, India, Laos, Myanmar, Nepal, Pakistan, Thailand, Vietnam, S China]

11. Leaf blade unlobed, margin dentate ............................................................................................... H. qinghaiensis [ China (Qinghai)]

– Leaf blade lyrate lobed, margin entire or toothed ............................................................................................................................12

12. Capitula few, usually 3–9, often long-peduncled, 2–3.5 cm wide; phyllaries greenish; achenes transversely muricate..................... .................................................................. H. heteromalla [ Afghanistan, NW Pakistan, N India, Nepal, Bhutan, Kashmir, SE Iran]

– Capitula usually numerous in corymbs, 0.5–2 cm wide; phyllaries brownish; achenes smooth or longitudinally ribbed ..............13

13. Capitula cylindric; phyllaries woolly-hairy............................. H. albescens [ Afghanistan, NW Pakistan, N India, Nepal, Kashmir]

– Capitula campanulate; phyllaries nearly glabrous............................................................................................................................14

14. Leaves mostly basal, usually lyrate-pinnatifid; achene apex faintly dentate ................. H. chitralica [E Afghnistan, NW Pakistan]

– Leaves sparsely arranged along the stem, usually lanceolate, often pinnately divided, base prominently amplexicaul; achene apex prominently dentate ............................................................................................................ H. afghana [E Afghnistan, NW Pakistan]

Figures

FIGURE 1. Himalaiella lushaiensis. A. habit. B. pappus. C. floret, with the pappus removed. D. floret. E. abaxial leaf surface. F. adaxial leaf surface. G. upper part of style with style branches. H. phyllaries (from left to right: inner to outer). I. achene. J. anther. Drawn from the holotype.

FIGURE 2. Distribution of Himalaiella lushaiensis (●) (circles indicate main cities).

FIGURE 3. Comparison of scanning electron micrographs of achenes of Himalaiella lushaiensis (A & C from holotype) and H. foliosa (B & D from holotype, Edgeworth 174, K000009621). A & B. overview. C & D. apical region. Scale bars: A = 1 mm. B = 0.5 mm. C = 0.5 mm. D = 0.2 mm.

FIGURE 4. Comparison of phyllaries of Himalaiella lushaiensis (A from holotype) and H. foliosa (B from holotype, Edgeworth 174, K000009621). Phyllaries are arranged from inner to outer series.