Acilepis D.Don, Prodr. Fl. Nepal: 169. 1825.

Bunwong, Sukhonthip, Chantaranothai, Pranom & Keeley, Sterling C., 2014, Revisions and key to the Vernonieae (Compositae) of Thailand, PhytoKeys 37, pp. 25-101 : 32

Acilepis D.Don, Prodr. Fl. Nepal: 169. 1825.

Lysistemma Steetz, Naturw. Reise Mossambique [Peters] 6(Bot., 2): 340. 1864.

Xipholepis Steetz, Naturw. Reise Mossambique [Peters] 6(Bot., 2): 344. 1864.

Type.

Acilepis squarrosa D.Don, Prodr. Fl. Nepal. 169. 1825.

Perennial herbs. Stems acaulescent or caulescent. Leaves simple, alternate or rosulate, petiolate, lamina ovate, obovate or elliptic, pubescent, margin serrate or entire, apex rounded, acute or acuminate, base cuneate or attenuate, subcoriaceous. Capitulescences terminal or axillary, corymbose, paniculate, spiciform, scapose, solitary. Capitula discoid, homogamous, pedunculate or sessile, florets bisexual and fertile. Involucres herbaceous. Florets 6-80; corollas purple to white, actinomorphic, lobes 5. Anthers 5. Styles purple, 2-branched, inner surface covered with stigmatic papillae, outer surface covered with sweeping hairs reaching to below style bifurcation. Achenes subterete or obovate, usually 10-ribbed, carpopodium present. Pappus in 2 series of bristles, persistent, the outer ones are shorter than the inner ones. Pollen lophate, 3-porate, without micropuncta.

Sixteen species are recognized in Thailand.

Key to the species of Acilepis in Thailand

1	Capitula with more than 30 florets	2
-	Capitula with less than 30 florets	6
2	Phyllaries mostly reflexed	3
-	Phyllaries not reflexed	4
3	Leaves basal; corolla and achenes pubescent	Acilepis attenuata
-	Leaves cauline; corollas and achenes without pubescence	Acilepis silhetensis
4	Capitula terminal, pedunculate	5
-	Capitula axillary, sessile	Acilepis squarrosa
5	Phyllaries with dense tomentum; capitula subsessile	Acilepis doichangensis
-	Phyllaries with sparsely arachnoid hairs; peduncles elongate	Acilepis ngaoensis
6	Capitula pedunculate, involucre ≥ 5 mm long	7
-	Capitula subsessile, involucre ≤ 5 mm long	Acilepis divergens
7	Phyllaries herbaceous, apex mucronate or aristate	8
-	Phyllaries scarious, spinose	Acilepis chiangdaoensis
8	Leaves chartaceous; achenes pubescent	9
-	Leaves membranaceous; achenes lacking trichomes	Acilepis peguensis
9	Upper leaves elliptic, acute to acuminate; achenes glandular	10
-	Upper leaves linear-lanceolate to falcate, or caudate; achenes eglandular	Acilepis principis
10	Leaves subsessile or with petioles up to 6 mm long	11
-	Leaves petiolate, petioles up to 25 mm long	13
11	Capitula with ≥ 20 florets, involucres cup-shaped or campanulate	12
-	Capitula with 8-12 florets, involucres narrowly campanulate	Acilepis kingii
12	Herbs 1-2 m tall; leaves 15-20 by 5-8 cm	Acilepis namnaoensis
-	Herbs 0.2-0.4 m tall; leaves 4-6 by 1-2.5	Acilepis kerrii
13	Corolla without hairs; achenes 2-3.5 mm long	14
-	Corolla with sparse hairs; achenes 4-5 mm long	Acilepis saligna
14	Inner pappus 8-9 mm long; involucres 8-10 mm long	15
-	Inner pappus 6-7 mm long; involucres 6-7 mm long	Acilepis virgata
15	Receptacle glabrous	16
-	Receptacle pubescent	Acilepis tonkinensis
16	Phyllaries and peduncles densely villose; pappus 6-7 mm long; anthers purple	Acilepis pseudosutepensis
-	Phyllaries and peduncles sparsely pilose; pappus 8-9 mm long; anthers yellowish	Acilepis sutepensis