TAXONOMIC TREATMENT
KNOXIA
L., Sp. Pl.: 104. 1753. − Vissadali Adans., Fam. Pl. 2: 145. 1763. − Cuncea Buch.-Ham. ex D.Don, Prodr. Fl. Nep.: 135. 1825. − Dentallaria Kuntze, Rev. Gen. Pl. 1: 280. 1891. − Spermacoce Roxb., [Hort. Beng.: 10. 1814, nom. nud. ex] Fl. Ind. 1: 372. 1820, pro parte. Type: K. zeylanica L.
Annual or perennial herbs or undershrubs. Stem erect, subterete with axillary shoots, rarely unbranched or with basal rosette of leaves. Leaves opposite, petiolate or sessile; stipules interpetiolar, fimbriate. Inflorescences terminal or both terminal and axillary, thyrso-paniculate, lax and corymbose, variously congested or head-like. Flowers 4-merous, dimorphic, heterostylous. Calyx tube short hairy inside; lobes unequal, sometimes foliaceous. Corolla white, pale lilac or pink, lobes valvate in bud, spreading in open flowers, uncinate at apex, dimorphic, hypocrateriform to fundibular in short-styled form or tubular-campanulate with narrow tube and swollen mouth in long-styled form. Stamens 4, epipetalous, exserted in short-styled form and included in long-styled form; anthers dorsifixed, linear-obleng, attached to the middle of the corolla tube; filaments pubescent near attachment. Ovary 2-locular, each with a solitary ovule pendulous ovule from an apical placenta; style exserted or included; stigma bifid, equal. Fruit dry, dehiscent to tardily dehiscent into two indehiscent mericarps and supported by variously shaped carpophores. Seed ellipsoidal, dorsally compressed and keeled, ventrally concave.
Key to the species
1. Leaves basal 1. K. rosettifolia
1. Leaves cauline 2
2. Leaves typically linear-lanceolate, sessile or less than 3 mm long. Fruit with
obtuse apex, lateral grooves absent or present only towards the base. Stipules
with 2-4 bristles 2. K. roxburghii
2. Leaves oblong- or ovate-lanceolate with petioles (5-) 10-20 mm long. Fruit
with emarginate apex, lateral grooves running along whole length. Stipules
with 4-6 bristles 3. K. sumatrensis
1. Knoxia rosettifolia Geddes, Bull. Misc. Inform. Kew 1927: 172. 1927. Type: Thailand, Chiang Mai, Mae Rim, 1,100 m, 5 July 1922, open grassy pine forest, alt. 1,100 m, A.F.G. Kerr 6249 (holotype K n.v., isotype BK barcode BK257379). Fig. 1.
Subscapose perennial 8−35 cm tall, with a basal leaf rosette made up of 2−4 pairs of decussate. Leaves sessile, obovate to ovate-elliptical, (2−) 2.5−6 by 1−1.5 cm, sparsely pubescent but with longer, stiff hairs on veins (flowering axis usually leafless or sometimes with few small, lanceolate leaves up to 2.5 cm long and < 1 cm wide); stipules 3−4 mm long, with 3 bristles, sparsely hairy. Inflorescence several-flowered, congested, head-like, to c. 1.5 cm in diam., on unbranched peduncle 7−33 cm long. Flowers shortly pedicellate to subsessile, c. 1 mm in fruit. Calyx slightly unequal, 1 lobe to c. 0.5 mm long, the others up to 0.3 mm. Corolla pink, mauve or purplish, glabrous outside; tube 1.5−2.5 mm long, cylindrical in brevistylous flower and widened above in longistylous flower; lobes 0.5−1 mm long, ovate to oblong. Stamens 4.5−5 mm long and exserted in short-styled morph, included in the widened upper corolla tube portion and 1−2.5 mm in long-styled morph; anthers c. 1 mm. Ovary to c. 1 mm long, obovoid; style exserted and 3.5−4 mm long in long-styled morph, included and to 2 mm long in short-styled morph; stigma lobes c. 0.5 mm long. Fruit dark brown, ovoid, 1−1.5 by 1.5−1.7 mm, laterally compressed, ventrally grooved; mericarps splitting from the base upwards, leaving behind the carpophore.
Thailand.– NORTHERN: Mae Hong Son (Khun Yuam), Chiang Mai (Mae Rim).
Distribution.– Endemic.
Ecology.– Open, grassy pine forest, 600-1,100 m alt. Flowers and fruits June - July, fruits to Oct.
Vernacular.– Kradum bai jook (กระดุมใบจุก).
Note. – Rare and only known from few collections.
2. Knoxia roxburghii (Spreng.) M.A. Rau, Bull. Bot. Surv. India 10, suppl. 2: 40. 1969. Fig. 2.
Spermacoce roxburghii Spreng., Syst. Veg., ed. 16, 1: 404. 1824. Type: India, Bengal, Roxb., Icon.: t. 2032 (CAL), lectotype designated by R. Bhattacharjee & Deb (1985).
Spermacoce laevis Roxb. [Hort. Beng.: 10. 1814, nom. nud. ex] Fl. Ind. 1: 374. 1820, non Lamk. (1792). Type: not located.
Spermacoe brunonis Blinkworth in Wall., Numer List: 822. 1829, nom. nud.
Knoxia laevis (Roxb.) DC., Prodr. 4: 570. 1830.
Spermacoce brunonis Wall. ex G.Don, Gen. Hist. 3: 621. 1834.
Knoxia brunonis (Wall. ex G.Don) Benth. & Hook.f., Gen. Pl. 2(1): 104. 1873.
S. roxburghiana Schult., Mant. 3: 199. 1874. Type: not located.
Knoxia brachycarpa R. Br. [in Wall., Numer. List: 821. 1829] ex Hook.f., Fl. Birt. India 3: 130. 1880. Type: Nepal, Wall., Numer. List: 281. 1829 (K-W left hand specimen, microfiche CAL).
Knoxia microcarpa Kurz, J. Asiat. Soc. Bengal Pt. 2, Nat. Hist. 46: 138. 1877. Syntyes: Myanmar, Pegu, 27 December 1870, Kurz 3083 (CAL); Irrawaddy, Sittang valley, Kurz 1433 (CAL), erroneously as K. macrocarpa in Hook.f., Fl. Brit. India 3: 130. 1880.
Hedyotis glauca W.W. Smith, Bull. Misc. Inform. Kew 1911: 344. 1911. Syntypes: Myanmar, Upper Burma, Kachin hill near Myit Kyina, Shaik Mokim 86 (CAL); India, Assam, Darrang Dt, Charali near Bishnath, Burkill 32470 (CAL).
Knoxia valerianoides Thorel ex Pit. in Lecomte, Fl. Indo-Chine 3: 289. 1923; Syntypes, Cambodia, Kampot, Hahn s.n.; Vietnam, Cochin-China, Cnia-tong, Thorel s.n.; China, Yunnan, Kony, Tcheon s.n.
Knoxia wallichii L. Bruce ex Panigarhi, Bull. Bot. Soc. Beng. 21(1): 29. 1967. Type: India, Meghalya, Garampani, 30 October 1956, Panigarhi 4246 (BSD).
Knoxia roxburghii (Spreng.) M.A. Rau subsp. brunonis (Hook.f.) R. Bhattacharjee & Deb var. brunonis Bhattacharjee & Deb, J. Econ. Tax. Bot. 6(1): 85. 1985.
Knoxia roxburghii (Spreng.) M.A. Rau subsp. brunonis (Hook.f.) R. Bhattacharjee & Deb var. glauca (W.W. Smith) Bhattacharjee & Deb, J. Econ. Tax. Bot. 6(1): 85. 1985.
Knoxia brachycarpa R. Br. ex Hook.f. var. congesta Pit. in Fl. Indo-Chine 3(2): 289. 1923. Type:
Herbaceous perennial 20−100 cm tall. Stems mostly unbranched, sparsely adpressed pubescent, sometimes glabrescent below. Leaves (sub)sessile, typically linear-lanceolate, 5−16.5 by 0.5−2.5 cm, base cuneate, apex acute, sparsely greyish pub¬escent above, denser below and with rusty brown hairs along veins; stipules 2−10 mm high, with 2−4 bristles 5−7 mm long. Inflorescence thyrso-paniculate, lax, cory¬mbiform and extensive or with several to few rather contracted to distinctly head-like partial inflorescences (cymes) and, in general, quite reduced; congested, head-like cymes somewhat elongating in fruit. Flowers shortly pedicellate to subsessile, but pedicels up to c. 3.5 mm in fruit. Calyx slightly unequal, 1 lobe to c. 0.7 mm long, the others < 0.5 mm. Corolla violet, violet pink, pink, pale pink or lilac, glabrous outside; tube 2−4 mm long, sparsely pubescent inside around the throat, cylindrical in short-styled and widened above in long-styled morph; lobes 1−1.5 mm long. Stamens 2−3.5 mm long and exserted in short-styled morph, included in the widened upper corolla tube portion and 1−2 mm in long-styled morph; anthers 0.5−1 mm. Ovary 0.5−1 mm long, obovoid to oblong; style exserted and 4.5−5 mm long in longistylous flower, included and to c. 2.5 mm long in brevistylous flower; stigma lobes c. 0.5 mm long. Fruit greyish to dark brown, obovoid, 1−2 by 1−1.8 mm, laterally compressed, ventrally grooved, dorsally rounded; mericarps splitting from the base upwards, leaving behind the carpophore.
Thailand.– NORTHERN: Mae Hong Son (Between Mae Sariang – Mae La Noi), Chiang Mai (Bo Luang, Doi Inthanon, Hod, Huai Chang Khian, Mae Tang, Ob Luang), Chiang Rai, Phayao, (Mueang), Lamphun (Ban Kun Tan-Doi Khun Tan, Mae Ta, Pa Sang), Tak (Doi Car, Phob Phra, Raheng, Umphang), Phitsanulok; NORTH-EASTERN: Phetchabun ((Nam Nao), Loei (Phu Kradueng), Sakon Nakhon (Phu Phan), Mukdahan (Khao Ma No), Khon Kaen; EASTERN: Chaiyaphum (Ban Nam Phrom-Tunkamang); SOUTH-WESTERN: Kanchanaburi (Si Sawat, Ban Dinso, Thong Pha Phum), Phetchaburi; CENTRAL: Bangkok (Watthana); SOUTH-EASTERN: Prachinburi (Aranya Prathet-Krabinburi).
Distribution.– India, Nepal, Myanmar, China, Cambodia, Laos, Vietnam.
Ecology.– Open thicket or grassy places in deciduous dipetrocarp-oak, mixed deciduous and dry dipterocarp forests and pine savannah, usually growing in open, sometimes disturbed, grassy areas, on clayey soil and also over limestone; occasionally in marshy, water-logged areas. 50-1,300 m alt. Flowers (March-) May - September; fruits July - October.
Vernacular.– Kradum bai yai (กระดุมใบใหญ่), ya khamen (หญ้าเขมร), ya khamen lek (หญ้าเขมรเล็ก) (Genral), ya klet hoi (หญ้าเกล็ดหอย), ya rak khao (หญ้ารากขาว) (Prachin Buri).
Note.– Bhattacharjee & Deb (1985) separated Knoxia roxburghii into subsp. roxburghii, subsp. brunonis and var. glauca on the basis of “lax, cormybose” vs “dense, rarely lax capitate to globose heads” is not accepted because, at least in Thai material, there is too much variation in this character, and because development of the plant and its inflorescence appears to depend on the habitat conditions. However, we have examined all materials and can find no differences and we also agree with Puff & Robbrecht (1989) that the inflorescence can vary considerably within the species.
3. Knoxia sumatrensis (Retz.) DC., Prodr. 4: 569. 1830. Fig. 3.
Spermacoce sumatrensis Retz., Observ. Bot. (Retzius) 4: 23. 1786. Type: Indonesia, Sumatra, Wennerberg s.n. (holotype LUND).
Knoxia sumatrensis Wall., Numer. List: 6183. 1831, nom. invalid., nom. nud.
K. corymbosa Willd., Sp. Pl. 1: 582. 1798, nom. illeg. Type: India, Velore, Klein s.n. (W, microfiche CAL).
K. stricta Gaertn., Fruct. Semi. Pl. 1: 122, t. 25. 1788. Type: Sri Lanka, Koenig s.n. (BM).
S. teres Roxb., Fl. Ind., ed. Carey & Wall. 1: 373. 1820, Icon t. 1335 (CAL). Lectotype: Coorg, F. Ham s.n. (Grown in Hort. Bot. Cal.) in Wall., Numer. List 819H. 1829 (K-W).
S. exserta Roxb., Fl. Ind., ed. Carey & Wall. 1: 374. 1820. Type: Coromondal, F. Ham s.n. (Grown in Hort. Bot. Cal.) in Wall., Numer. List: 820C. 1829 (K-W).
S. corymbosa Roth, Nov. Gen. Sp.: 98. 1821, non Retz. 1786. Type: Ind. Or., B. Heyne s.n. BM).
Cuncea trifida Buch.-Ham. ex D. Don, Prodr. Fl. Nepal.: 135. 1825. Type: Nepal, Buch.-Ham. s.n. (CAL).
K. mollis R.Br. in Wall., Numer. List: 820. 1829, nom. illeg. Type: Wall., Numer. List: 820. 1829 (CAL, K-W).
K. heyneana DC., Prodr. 4: 570. 1830. Type: Ind. Or., B. Heyne s.n. (BM).
var. sumatrensis Wright & Springate in Grierson & Long, Fl. Bhutan 2(2): 794. 1999.
Subshrubby perennial to 1 m tall. Stems often branched, sparsely to densely tomentose above, glabrescent below. Leaves oblong- or ovate-lanceolate, 4−10 by 1−4 cm, base acute to attenuate or obtuse, apex acute to acuminate, above sparsely pubescent, below pubescent, particularly on the veins, with 5-12 pairs of lateral veins; petioles (5−) 10−20 (−30) mm long; stipules 3.5−10 (−15) mm high, with typically 4−6 bristles 5−10 mm long. Inflorescence thyrso-paniculate, often corymbiform and rather lax; cymes much elongating in fruit; peduncle 2−7 (−10) cm long. Flowers shortly pedicellate to subsessile but pedicels up to c. 2 mm in fruit. Calyx slightly unequal, 1 lobe to c. 0.7 mm long, the others < 0.5 mm. Corolla white, yellowish-white, pinkish-white, pale rose, pale lilac or pale blue-violet, glabrous outside; tube 2−6 mm long, pubescent inside at least around the throat, cylindrical in short-styled and widened above in long-styled morph; lobes 1−3 mm long. Stamens 2−4 mm long and exserted in short-styled morph, included in the widened upper corolla tube portion and 1.5−2 mm in long-styled morph; anthers 0.5−1 mm. Ovary to 1−1.5 mm high, ovoid to oblong; style exserted and 5−10 mm long in longistylous flower, included and 1−5 mm long in brevistylous flower; stigma lobes ca. 0.5 mm long. Fruit greyish to dark brown, 1−3 by 0.8−2.4 mm, faintly to distinctly quadrangular; mericarps often remaining (partially) united, leaving behind the column-like, apically 2-forked carpophore, but sometimes splitting from the base into 2 one-seeded units.
Thailand.– NORTHERN: Chiang Mai (Doi Inthanon, Doi Chiang Dao, Doi Suthep, Doi Tao, Hod, Huai Chang Khian), Chiang Rai (Doi Fa Hom Pok), Nan (Doi Phu Wae), Lamphun, Lampang (Doi Khun Tan, Doi Luang, Doi Pa Lad, Jae Sawn), Phrae, Tak (Bhumipol Dam, Mae Kor), Kamphaeng Phet (Mae Wong, Klong Lan); NORTH-EASTERN: Loei (Phu Kradueng, Wang Saphung), Sakon Nakhon (Pha Sawoi), Mukdahan, Kalasin (Somdet), Nakhon Phanom (Don Tan), Mukdahan (Huai Huad), Khon Kaen; EASTERN: Chaiyaphum (Phu Khieo); Nakhon Ratchasima (Bua Yai, Sakaerat, Wang Nam Khieo), Buriram, Ubon Ratchathani (Khong Chiam); SOUTH-WESTERN: Uthai Thani (Huay Kha Kaeng); Kanchanaburi (Ban Dinso, Hin Dat, Khao Buing, Si Sawat), Phetchaburi (Huay Sai), Prachuap Khiri Khan (Thabsakae); CENTRAL: Lop Buri (Lam Narai), Saraburi (Ban Nong Bua, Pu Kae), Krung Thep Maha Nakhon (Watthana). SOUTH-EASTERN: Sa Kaeo (Watana), Prachin Buri (Aranyaprathet), Chon Buri (Khao Kieo, Si Chang); PENINSULAR: Chumphon (Pathio, Thung Maha), Phangnga (Ko Yao, Ko Yao Noi).
Distribution.–Sri Lanka, India, Sikkim, Bhutan, Bangladesh, China, SE Asia, Australia (Queensland).
Ecology.– Sandy ground in dipterocarp, dry deciduous, mixed deciduous, open pine-oak and hill evergreen forests, usually growing in undisturbed or disturbed open (grassy) areas on sandy to rocky ground; sometimes over limestone, 0-1,700 m alt., Flowers and fruits May-November (fruits to January).
Vernacular.– Tong lai (ตองลาย) (Chiang Rai), ma khok taek (ม้าคอกแตก), hak ma han (ฮักมะหาน) (Chiang Mai).