Flora of Thailand Euphorbiaceae

 

2. Actephila

This page has been changed, Actephila excelsa and A. javanica are considered to be the same species, A. excelsa var. acuminata is recognised as a distinct species under the name A. subsessilis and A. saccata is added as new species. 

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Genus description

Identification key

Species descriptions

Actephila

Blume, Bijdr. Fl. Ned. Ind.: 581. 1825; Benth., Gen. Pl. 3:269. 1880; Pax & K.Hoffm. in Engl., Pflanzenr. VI.147.xv: 191. 1922; Backer & Bakh.f., Fl. Java 1: 470. 1963; Airy Shaw, Kew Bull. 25: 496. 1971; Whitmore, Tree Fl. Malaya 2: 51. 1973; Airy Shaw, Kew Bull. 26: 208. 1972; Kew Bull. Add. Ser. 8: 21. 1980; G.L.Webster, Ann. Missouri Bot. Gard. 81: 37. 1994; Radcl.-Sm., Gen. Euphorbiacearum: 10. 2001; Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 35. 2005; G.L.Webster in Kubitzki, Fam. Gen. Vasc. Pl. 11: 66. 2014; Heijkoop & Welzen, Blumea 62: 9. 2017. — Lithoxylon Endl., Gen.: 1122. 1840.— Anomospermum Dalzell, Hook. J. Bot. Kew Gard. Misc. 3: 228. 1851 (non Miers, 1851).— Savia Willd. sect. Actephila (Blume) Baill., Étude Euphorb.: 571. 1858.

Trees or shrubs; monoecious.  Indumentum simple hairs, usually subglabrous.  Stipules caducous.  Leaves alternate, long or short-petioled; blade chartaceous or coriaceous, margin entire, penninerved.  Inflorescences usually solitary (or fascicled), axillary or extra-axillary, when fascicled on short raceme with few pistillate flowers at base, upwards only with staminate ones.  Flowers: sepals 5, subequal, imbricate; petals 5, shorter than sepals; disk a large, 5-lobed ring.  Staminate flowers: pedicel very short; stamens 3–6, filaments free or basally connate, on the disc; anther-cells parallel; pistillode 3-lobed.  Pistillate flowers: pedicel very long; calyx often persistent and enlarged in fruit; ovary 3-locular; ovules 2 per locule; style short, stigmas 2-fid at apex, persistent.  Fruits capsules, loculicidally (and partly septicidally) dehiscent.  Seeds large, without aril or caruncle; trigonous, almost without albumen.

    An Asian/Australian genus of ca. 20 species. 4 species in Thailand.  Classification: Subfam. Phyllanthoideae, tribe Wielandieae.

Key to the species

1.  Actephila collinsae Hunter, Misc. Inf. Kew Bull. 1924: 96. 1924; Gagnep. in Lecomte, Fl. Indo-Chine 5: 537. 1927; Smitinand, Nat. Hist. Bull. Siam Soc. 20: 139. 1962 Airy Shaw, Kew Bull. 26: 208. 1972; Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 36, fig. 4. 2005.— Actephila siamensis Pierre ex Gagnep.: 531; Smitinand Nat. Hist. Bull. Siam Soc 20: 140. 1962.

Shrub, 1–2 m high; branches sparsely pilose, angular, light brown when young, soon glabrous, terete and greyish, lenticellate.  Stipule c. 2 mm long.  Leaves: pseudo-verticillate, crowded at the end of branches; petiole 3–6 mm long; blade oblanceolate, elliptic or obovate, 8–15.5 by 2.5–5 cm, coriaceous, base cuneate, apex usually obtuse, sometimes bluntly acute, glaucous or glaucescent beneath; nerves 10–12 pairs, inconspicuous on both surfaces, finely reticulation.  Staminate flowers: pedicels c. 5 mm long; sepals ovate-lanceolate, ovate or oblong-lanceolate, c. 5 by 2.5 mm wide, sparsely hairy outside, apex obtuse, entire; petals c. 0.5 mm long, pale yellow; disc entire; stamens free, anthers more or less globose. Pistillate flowers: solitary; pedicels 1.5–4 cm long, glabrescent on the upper, gradually thickened; sepals ovate to elliptic, c. 6 by 5 mm wide, apex rounded or obtuse, glabrous, enlarged in fruit, 9-veined; disc annular; ovary velutinous; stigmas c. 3 mm long.  Fruit c. 2 by 1.5 cm high, sepals accressent to 12 by 8 mm wide, greenish.  Seed 1.

    T h a i l a n d.— SOUTH-WESTERN: Uthai Thani (Lan Sak), Phetchaburi (Winit 552-type, BK, BKF); Prachuap Khiri Khan (Sam Roi Yot National Park).

    D i s t r i b u t i o n.— Endemic.

    E c o l o g y.— On dry limestone hills; alt. 100–300 m.  Flowering: March; fruiting: August.

    V e r n a c u l a r.— Si som (สีส้ม) (Phetchaburi).

    N o t e s.— This species is very distinct in the accrescent fruiting sepals and the glaucous or glaucescent on the lower sides of the leaves.  It is different from A. ovalis by the leaves not acuminate, nerves inconspicuous, stigmas free (style absent).

2.  Actephila excelsa (Dalzell) Müll.Arg., Linnaea 32: 78. 1863; in DC., Prodr: 15, 2: 222. 1866; Hook.f., Fl. Brit. Ind. 5: 282. 1887; Pax & K.Hoffm.in Engl., Pflanzenr. VI.147.xv: 191. 1922; Ridl., Fl. Mal. Pen. 3: 196. 1924; Gagnep in Lecomte, Fl. Indo-Chine 5: 535. 1927; Henderson, J. Mal. Br. Roy. As. Soc. 17: 68. 1939; Backer & Bakh.f., Fl. Java 1: 470. 1963; Airy Shaw, Kew Bull. 26: 209. 1972; Whitmore, Tree Fl. Mal. 2: 52. 1976; Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 36, fig. 5. 2005; Heijkoop & Welzen, Blumea 62: 14, map 3. 2017.— Savia actephila Hassk., Cat. Hort. Bogor.: 243. 1844.— Anomospermum excelsum Dalzell, Hook. J. Bot. & Kew Garden Misc. 3: 228. 1851.— Actephila javanica Miq., Fl. Ned. Ind. 1, 2: 356. 1859; Airy Shaw, Kew Bull., Addit. Ser. 8: 22. 1980; Kew Bull. 37: 4. 1982; Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 38, fig. 6. 2005.— Actephila excelsa (Dalzell) Müll.Arg. var. javanica (Miq.) Pax & K.Hoffm. in Engl., Pflanzenr. VI.147.xv: 192. 1922; Airy Shaw, Kew Bull. 26: 209. 1972; Whitmore, Tree Fl. Malaya 2: 52. 1973.— Actephila excelsa (Dalzell) Müll.Arg. var. excelsa: Airy Shaw, Kew Bull. 26: 209. 1972.— Actephila excelsa (Dalzell) Müll.Arg. var. brevifolia N.Balach., Mahesw. & Chakrab., J. Econ. Taxon. Bot. 33: 717, fig. 1. 2009.

Shrubs to tree(let)s, up to 10(–15) m high, d.b.h. up to 30 cm. Leaves: petioles 5–95 mm long, glabrous to slightly to completely puberulous; blade elliptic (to ± obovate), (4-)5.5–35.5 by (1.1–)1.9–13.5(–15.9) cm, , papyraceous to pergamentaceous, base acute to obtuse, margin flat, apex cuspidate (to acuminate or rarely acute), glossy, light to dark green above, paler green below; nerves (5-)7–16 per side. Flowers solitary to fascicled, staminate ones often cauliflorous or ramiflorous, pistillate ones axillary; pedicels widening towards apex; sepals light green to white (with pink base), margin sometimes slightly membranous, apex acute to obtuse; petals: apex truncate to obtuse or rounded, erose, white to greenish white; disc a narrow thin ring, light yellow. Staminate flowers 2–3 mm diam; pedicels ca 2 mm long; sepals ovate to elliptic to diamond shaped, widest just below to in the middle, 1.3–2 by 1.2–2 mm, green to light green; petals 1–2 by 0.8–1 mm; stamens free, ca 2 mm long, greenish to white, anthers (light) yellow. Pistillate flowers 3–5 mm diam, white to greenish; pedicel 8–31(–53) mm long; sepals ovate to elliptic to somewhat diamond shaped to obovate, widest just below to just above the middle, (1.5–)2–4(–5) by (1–)1.5–3(–3.5) mm, green to greenish white; petals (0.6–)0.7–2 by (0.3–)0.5–1.3 mm, sometimes somewhat split into two; disc slightly covering base of sepals in fruit; ovary 0.8–2.5 by 0.9–3 mm, green to green-white, glabrous, stigmas 0.4–0.6 mm long, basally pinkish, apically light green. Fruits 1.3–2 cm diam, pendent, brown; pedicels elongating up to 75 mm long, (0.4–)0.7–1.5 mm diam, often curved, apically thickening; sepals not elongating, reflexed to flat when dry; columella 5–8 mm long. Seeds 7–12 mm long, 5–10 mm wide, 5–9 mm high, widened seeds (7–)8–13 mm long, (6.5–)9–11(–14) mm wide, 5–8(–9) mm high.

    T h a i l a n d.— NORTHERN: Chiang Mai (Doi Inthanon, Doi Chiang Dao), Chiang Rai (Doi Tung); SOUTH-EASTERN: Chanthaburi (Makham); PENINSULAR: Ranong (Klong Nakha Wildlife Sanctuary, Ngao Waterfalls), Surat Thani (Khao Sok, Khao Wong, Klong Phanom National Park), Phuket, Krabi (Ko Phi Phi), Nakhon Si Thammarat (Garon Waterfalls, Chwang), Patthalung (Khao Pu Khao Ya), Trang (Khao Chong), Satun (Tarutao National Park), Songkhla (Khao Chum Sak at Hat Yai).

    D i s t r i b u t i o n.—  India, Sri Lanka, Myanmar, S. China, Thailand, Indochina, Malay Penisula, Sumatra, Java, Borneo, Philippines, Sulawesi.

    E c o l o g y.— In evergreen forest, montane forest, along streams, on rocky limestone hills; alt. to 1200 m. Fruiting: August to October.

3.  Actephila ovalis (Ridl.) Gage, Rec. Bot. Surv. Ind. 9: 219. 1922; Ridl., Fl. Mal. Pen. 3: 196. 1924; Gage, J. Asiat. Soc. Bengal, Pt. 2, Nat. Hist. 75: 519. 1936; Henderson, J. Mal. Br. Roy. Asiat. Soc. 17: 68. 1939; Smitinand, Nat. Hist. Bull. Siam Soc. 20: 139. 1962; Airy Shaw, Kew Bull. 26: 210. 1972; Whitmore, Tree Fl. Mal. 2: 51. 1973; Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 38, fig. 7, plate II: 1. 2005; Heijkoop & Welzen, Blumea 62: 19, fig. 6, map 5. 2017. — Dimorphocalyx ovalis Ridl., J. Roy. As. Soc. Str. Br. 59: 178. 1911.

Small trees or shrubs, 0.5–2 m high, puberulous, glabrescent.  Stipules ovate.  Leaves opposite or more or less whorled at the end of branches; petioles 0.3–1.2 mm long, hairy; blade lanceolate, elliptic, rarely obovate, 8–20.5 by 2–5 cm, subcoriaceous, base cuneate, margin undulate, apex acuminate to long acuminate, dark green above, green below; veins 10–14 pairs, looped near margins, inconspicuous on both surfaces, midrib sunken on the upper surface, raised below, reddish brown, shining.  Inflorescences axillary or on old branches, bracts ovate.  Flowers few, greenish. Staminate flowers: sepals whitish-cream or greenish, disc and filaments whitish, anthers yellow; ovary pale yellow.  Pistillate flowers: solitary; pedicels up to 6 cm long in fruit; sepals ovate, c. 2 by 1 cm, obtuse, yellowish green; ovary conical, pubescent, style absent, stigmas free.  Fruits  light yellow or green, turning black, with enlarged persistent calyx, sepals suborbicular or broadly elliptic or ovoid, 1–2.3 by 1–1.5 cm, 5–7 veins from the base, reticulation distinct.

    T h a i l a n d.— SOUTH-WESTERN: Prachuap Khiri Khan (Bang Saphan); SOUTH-EASTERN: Sa Kaeo (Pang Sida National Park); PENINSULAR: Surat Thani (Ko Tao), Pangnga (Khao Tham Thong Lang, Tap Put, Similan National Park), Krabi (Ban Nini Shong, Aoluk), Nakhon Si Thammarat (Khao Luang, Khiri Wong, Karom Waterfalls), Phatthalung (Khao Pu-Khao Ya National Park), Trang (Khao Chong), Satun (Kuan Sato, Talebun).

    D i s t r i b u t i o n.— North Malaya (Langkawi, Perlis, Kedah and Penang) (type).

    E c o l o g y.— Moist evergreen forest, common on  limestone hill; alt. 100–200  m.  Flowering: February to May; fruiting: May to July.

    N o t e s.— Differs from the more northerly A. collinsae in the green undersurface of the leaves and usually larger and thinner fruiting sepals. The distribution of the two do not appear to overlap.

4. Actephila saccata Welzen & Heijkoop, Thai Forest Bull., Bot. 44: 101. 2016.

Shrublets to shrubs, up to 1.5 m high. Leaves: petioles 3–10 mm long, glabrous to slightly hairy; blade obovate, 7.5–21 by 1.7–7 cm, papyraceous, base attenuately decurrent into petiole, base tip slightly obtuse, margin flat, apex cuspidate, surfaces glabrous, dark green above, pale green below; nerves 11–17 pairs. Flowers solitary, axillary; pedicels at most slightly widening towards apex, glabrous; sepals: apex obtuse; petals: apex rounded, entire; disc a wide, not very thin ring. Staminate flowers ca 14 mm diam; pedicels broken, more than 2 mm long; sepals ovate to oblong, ca 5.5 by 3–4 mm; petals obovate, ca 2 by 0.8 mm; stamens free, ca 2.5 mm long, anthers ca 0.8 by 1 mm, (light) yellow. Pistillate flowers ca 13 mm diam; pedicel 14–15 mm long, < 1 mm thick; sepals obovate, 6–7 by 3.5–4.5 mm; petals obovate, ca 2 by 0.8 mm; disc ca 1 mm broad, ca, 0.5 mm thick, pushed downward by fruit wall; ovary ca 2 by 3 mm, glabrous, stigmas ca 1 mm long. Fruits ca 16 mm diam, ca 11 mm high, pendent, green (immature), basal part developing over disc and sepals, pushing these down; pedicels elongating up to 36 mm long, < 1 mm diam, not thickining, glabrous; sepals not elongating, reflexed; columella ca 5 mm long. Seeds 9–10 mm long, 8–9 mm wide, 6–7 mm high.

    T h a i l a n d.— SOUTH-WESTERN: Prachuap Khiri Khan (Kui Buri National Park: Middleton et al. 1239-type, A, BKF, E, L). PENINSULAR: Nakhon Si Thammarat (Kao Oktalu, Kao Hua Têk); Trang (Khao Pra Bang Khram Wildlife Sanctuary).

    D i s t r i b u t i o n.— Endemic in Thailand. 

    E c o l o g y.— Evergreen and secondary forest, probably only on limestone. Altitude: 50–200 m. Flowering in April; fruiting in January, May, August. 

    E t y m o l o g y.— The epithet refers to the base of the fruit extending over the disc and partly the sepals, pushing these downwards.

    I U C N  s t a t u s.— DD (Data deficient). 

    N o t e.— Typical for this species are the fruits of which the base extends downwards, pushing the disc and sepals downwards and enveloping these partly. Also typical are the large flowers on thin pedicels with big sepals that do not enlarge in fruit. Unlike A. excelsa, the pedicels remain slender in fruit and the leaves always have short petioles.

5. Actephila subsessilis Gagnep., Bull. Soc. Bot. France 71: 569. 1924; in Lecomte, Fl. Indo-Chine 5: 534. 1927; Heijkoop & Welzen, Blumea 62: 21, map 7. 2017.— Actephila excelsa (Dalzell) Müll.Arg. var. acuminata Airy Shaw, Kew Bull. 26: 209. 1972; Whitmore, Tree Fl. Malaya 2: 52. 1973. — Type: Ridley s.n. (holo K), Malaysia, Selangor, Batu caves.

Shrubs to trees. Leaves: petioles 1–6(–8) mm long; blade elliptic, 5.6–15 by 2.1–5.2 cm, papyraceous, base obtuse or acute, margin flat, apex cuspidate to gradually tapering into a widely cuspidate apex, abaxially basally somewhat puberulous on blade and venation; nerves 9–15 per side. Flowers solitary or paired. Staminate flowers unknown. Pistillate flowers ca 4 mm diam, yellow; pedicels 12–30 mm long; sepals ovate to elliptic or diamond shaped, widest just below the middle, c. 2–3 by 1–1.5 mm, apex obtuse; petals 0.8–1 by 0.4–0.8 mm, apex truncate to rounded, erose; disc a thin, narrow ring, slightly covering the base of the sepals in fruit; ovary ca 0.8 by 1.1 mm, glabrous, stigmas ca 0.5 mm long. Fruits green, c. 15 mm diam, pendent; pedicels 17–32 by 0.5–1 mm, somewhat curved, glabrous to sericeous, apically thickening; sepals not elongating; columella 4–6 mm long, basally completely covering disc and base of sepals, fibrous after dehiscence. Seeds 7–9.5 mm long, 6–7.5 mm wide, 5–6 mm high, widened seeds c. 8 mm long, 9.5–10.5 mm wide, 6–7 mm high.

    T h a i l a n d.— NORTHERN (); PENINSULAR ().

    D i s t r i b u t i o n.— Thailand, Vietnam, Malay Peninsula.

    E c o l o g y.— Only found on limestone. Altitude: 50–550 m. Flowering: April, July; fruiting: September, December, January.

    N o t e. — This species is vegetatively easily confused with A. ovalis, also present in the Malay Peninsula. Differences are the wavy instead of straight leaf blade margin of A. ovalis, and the accrescent calyx in A. ovalis up to 10–22 by 9–13 mm (against c. 2 by 1.4 mm in A. subsessilis).