HARVARD PAPERS IN BOTANY 5(1): 99-108. 2000.

A REVISION OF THE HIMALAYAN AND CENTRAL ASIAN GENUS TAPHROSPERMUM (BRASSICACEAE)

IHSAN A. AL-SHEHBAZ

Missouri Botanical Garden, P.O. Box 299, St. Louis, Missouri 63166-0299, U.S.A.

Abstract. Seven species of Taphrospernnum are recognized, of which six grow in China. The new combinations T. himalaicum, T. fontanum, T. verticillatum, T. lowndesii, and T. tibeticum are proposed. The new subspecies T. fontanum subsp. microspermum is described. A key to species is presented, and the relationship and distinguishing characters of Taphrospermum are given. The genus Glaribraya is reduced to synonymy of Taphrospermum.

Keywords: Brassicaceae, China, Glaribraya, Taphrospermum, taxonomy.

During work on many Himalayan, central Asian, and Chinese genera of the Brassicaceae (Cruciferae) for the forthcoming volume 8 of Flora of China, volume 2 (part 2) of the Flora of Nepal, and volume 4 of the Flora of Kazakstan, it became evident that the limits of several genera are artificially drawn and that many nomenclatural changes are needed to make the new names available for these floras. A case in point is the present revision of the genus Taphrospermum C. A. Meyer.

The initial work on Taphrospermum showed that it included only two species, but the generic boundaries seemed unclear, especially in relation to Cochlearia Linnaeus, Dilophia Thomson, Dipoma Franchet, Gignariella Baehni, Glaribraya H. Hara, Platycraspedum O. E. Schulz, and Staintoniella H. Hara. These genera are discussed below in relation to Taphrospermum, and revisionary studies on them are either in press or in preparation.

GENERIC LIMITS

With the addition of Taphrospermum platypetalum Schrenk in 1842 (see below), the genus Taphrospermum consisted of two species until the present study. Except for Hooker and Thomson (1861), Hooker (1862), and Hooker and Anderson (1872), who reduced Taphrospermum to synonymy of Cochlearia, the identity of the genus remained basically unchallenged. Hooker and Thomson (1861) indicated that C. himalaica J. D. Hooker & Thomson is closely related to T. altaicum C. A. Meyer, and Hooker and Anderson (1872) transferred the latter to Cochlearia. However, subsequent botanists maintained C. himalaica in Cochlearia. In fact, as circumscribed by Hooker and Thomson (1872), Cochlearia was so heterogeneous that the three species they recognized are presently assigned to Taphrospermum, Rorippa Scopoli, and Pegaeophyton Hayek & Handel-Mazzetti.

In my opinion, Taphrospermum and Cochlearia are sufficiently different and should be recognized as independent genera. Species of Taphrospermum have fleshy fusiform to conical roots basally with a crown of scalelike leaves, distinctly petiolate leaves, inflorescences bracteate throughout or rarely only basally, dilated bases of median staminal filaments, confluent nectar glands with well-developed median nectaries, strongly flattened replums, and thin papery to membranous fruit valves. By contrast, species of Cochlearia have slender, nonfleshy taproots without basal scalelike leaves, sessile or petiolate leaves, ebracteate inflorescences, toothlike nonconfluent nectaries without median glands, terete replums, and thick fruit valves.

Maximowicz (1880, 1889) indicated that Dilophia fontana Maximowicz is similar to Taphrospermum platypetalum, and he commented on Hooker's (1862) merger of Taphrospermum and Cochlearia by indicating how artificial the delimitation of the genera of the Cruciferae has become. Both D. fontana and C. himalaica are herein transferred to Taphrospermum; the observations of Maximowicz (1880) and Hooker and Thomson (1861) regarding their similarities to Taphrospermum are quite accurate, though they were overlooked for about 120 years. Maximowicz (1880, 1889) was probably influenced by fruit shape in the placement of D. fontana in Dilophia (fruit obcordate) instead of Taphrospermum (fruit narrowly conical), but the species is more at home in Taphrospermum, and it differs significantly from the rest of Dilophia (see below).

Hara (1974, 1978) described four new genera of Brassicaceae from Nepal and Bhutan, of which Staintoniella and Glaribraya are pertinent to the present study. Staintoniella included two species quite different morphologically, of which the type, S. nepalensis H. Hara, has been transferred to Aphragmus Andrzejowski ex de Candolle (Al-Shehbaz, 2000). The second species, S. verticillata (Jeffrey & W. W. Smith) H. Hara, is so closely related to G. lowndesii H. Hara that they can only be separated by petal size, duration of sepals, seed sculpture, and presence versus absence of the fruit septum. The last two species are transferred in the present account to Taphrospermum because they share with members of this genus several important characters listed below. Hara (1978) indicated that Glaribraya resembles Staintoniella, Taphrospermum, Aphragmus, Archyosperma O. E. Schulz, and Dilophia, but he gave only a brief description that collectively separates it from these genera combined, and he did not discuss the similarities or differences individually.

The Himalayan Lignariella (four species) and the Chinese Dipoma (monotypic) resemble Taphrospermum in having petiolate leaves, bracteate inflorescences, confluent glands, entire stigmas, and flattened replums, but these genera do not appear to be closely related. Lignariella is readily separated by its purple to lavender petals, palmately veined and lobed leaves, spreading stamens equal in length, and pedicels papillate adaxially. Its relationship to Taphrospermum and other Himalayan genera are dealt with separately (Al-Shehbaz et al., 2000a). Taphrospermum has white petals, entire or rarely dentate and pinnately veined leaves, erect to ascending tetradynamous stamens, and pedicels either glabrous or pubescent all around. Dipoma differs from Taphrospermum by being perennials with slender rhizomes, branched trichomes, strongly curved and loopforming fruiting pedicels, conical styles, subapical placentation, and nectaries consisting of four lateral glands. By contrast, Taphrospermum plants are biennials with fleshy taproots, simple trichomes, straight fruiting pedicels, often cylindric styles, parietal placentation, and confluent nectaries forming a complete ring of median and lateral glands.

As circumscribed here, Taphrospermum consists of seven species with fusiform to narrowly conical fleshy roots, a crown of scalelike leaves at base of root from the center of which originates one or more stems, nonrosulate basal leaves, petiolate and pinnately veined cauline leaves and bracts, racemes bracteate throughout or rarely only basally, simple trichomes on inflorescence rachis, sepals, and/or fruit, nonsaccate sepals, white petals, dilated bases of median staminal filaments, nonapiculate and usually ovate anthers, annular lateral glands confluent with median nectaries, strongly flattened replum, thin papery to membranous fruit valves, and often foveolate (one species with papillate) seeds.

RELATIONSHIPS

Taphrospermum is most closely related to Platycraspedum, a Chinese genus of two species (Al-Shehbaz et al., 2000b). Both have fleshy roots, a crown of scalelike leaves at root base, petiolate cauline leaves, bracteate inflorescences, white petals, dilated base of median filaments, and flattened replums. However, Taphrospermum has pinnately veined cauline leaves and bracts, foveolate to rarely papillate seeds, dilated and entire filaments, equal and nonsaccate sepals, well-developed annular lateral nectaries confluent with median ones, and entire stigmas. By contrast, Platycraspedum has palmately veined cauline leaves and bracts, minutely reticulate seeds, strongly flattened and toothed median filaments, unequal sepals with the lateral pair saccate, poorly developed lateral nectaries with median ones lacking, and 2-lobed stigmas.

Taphrospermum is also closely related to Dilophia (two species; China, Himalaya, and Central Asia) being biennials with fleshy, fusiform roots, a crown of scaly leaves at root base, confluent nectaries, thin papery fruit valves, entire stigmas, and flattened replum. Taphrospermum has petiolate leaves and bracts, obtuse anthers, dilated bases of staminal filaments, well-developed stems, racemes strongly elongated in fruit, and fruit replum without horizontally oriented rim. Dilophia has sessile leaves and bracts, strongly apiculate anthers, slender bases of staminal filaments, abbreviated stems, racemes not elongated in fruit, and fruit replum with a rim oriented at 45 or horizontally.

TAXONOMIC TREATMENT

Taphrospermum C. A. Meyer in Ledebour, Fl. Altaic. 3: 172. 1831.

Type species: Taphrospermum altaicum C. A. Meyer.

Glaribraya H. Hara, J. Jap. Bot. 53: 135. 1978. TYPE: G. lowndesii H. Hara.

Herbs biennial. Trichomes simple, rarely absent. Roots often fleshy, narrowly fusiform, basally with a crown of deciduous or persistent scalelike leaves. Stems prostrate or ascending or erect. Basal leaves petiolate, not rosulate, simple, entire. Stem leaves petiolate, entire or rarely obscurely dentate, lowermost whorled or alternate. Racemes many flowered, bracteate throughout or rarely only basally. Fruiting pedicels ascending to divaricate, straight or recurved. Sepals oblong, erect, persistent or rarely caducous, glabrous or subapically pubescent, base of inner pair not saccate. Petals white, longer than sepals; blade obovate or broadly so, apex rounded to emarginate; claw obscure. Stamens 6, slightly tetradynamous; filaments of inner pairs dilated at base; anthers ovate, apex rounded. Nectar glands confluent, subtending bases of all stamens. Ovules to 12 per ovary. Fruit dehiscent siliques or silicles, cylindric or narrowly conical to obcordate, ovate, or oblong, angustiseptate, terete, or latiseptate, sessile or subsessile; valves distinctly veined, glabrous or papillate, torulose or smooth; replum broadly flattened throughout or only basally; septum complete, rarely absent or perforate and reduced to a rim; style to 3 mm long; stigma capitate, entire. Seeds uniseriate or biseriate, wingless, oblong, plump to flattened; seed coat foveolate to papillate, not mucilaginous when wetted; cotyledons incumbent, oblique, or accumbent.

Seven species: primarily in China, with one species distributed in Kazakstan, Kyrgyzstan, Mongolia, Nepal, Russia, and Tajikistan.

KEY TO THE SPECIES OF TAPHROSPERMUM

1a. At least some of the lowermost cauline leaves verticillate, other leaves opposite and/or alternate 2

1b. All leavesalternate ... 4

2a. Plants densely hirsute throughout with trichomes 0.5-1.0 mm long ... 7. T. tibeticum

2b. Plants glabrous, sparsely puberulent, or minutely papillose on inflorescence rachis and sepals. 3

3a. Petals broadly obovate, (7-)8-9(-10) x (3.5-)4.5-6.0 mm; sepals caducous; septum absent; seeds foveolate ... 5. T. verticillatum

3b. Petals narrowly obovate to spatulate, 3-5 x 1.5-2.0 mm; sepals persistent; septum complete; seeds papillate... 6. T. lowndesii

4a. Inflorescence bracteate only basally; fruit cylindric, terete; sepals glabrous ... 3. T. platypetalum

4b. Inflorescence bracteate throughout; fruit conical, obcordate, oblong or ovate, compressed and latiseptate or angustiseptate; sepals often pubescent ... 5

5a. At least some leaves dentate; fruit oblong to ovate, latiseptate ... 2. T. himalaicum

5b. Leaves entire or rarely repand; fruit narrowly conical or obcordate, angustiseptate at least basally ... 6

6a. Fruit obcordate, not torulose, (4-)5 7 mm wide; septum absent; cotyledons accumbent ... 4. T. fontanum

6b. Fruit narrowly concial, torulose, (1.8-)2.0-2.5(-3.0) mm wide; septum complete or rarely reduced to a rim; cotyledons incumbent ... 1. T. altaicum

1. Taphrospermum altaicum C. A. Meyer in Ledebour, Fl. Altaic. 3: 173. 1831. TYPE: [RUSSIA]. Tschuja [Chuya] River near mouth of Tschegan [Chegan] River, Bunge s.n. (Holotype: LE).

Synonyms: Cochlearia altaica (C. A. Meyer) J. D. Hooker & T. Anderson, Fl. Brit. India 1(1): 145. 1872.

Taphrospermum altaicum var. macrocarpum An, Acta Phytotax. Sin. 23: 396. 1985. TYPE: CHINA: Xinjiang, Bogda Shan, Xinjinag College Botanical Expedition 15152 (Holotype: XJU).

Herbs (4-)10-23(-30) cm tall, with narrowly fusiform roots, glabrous throughout except for puberulent fruit. Stems prostrate, sometimes ascending to erect, few to numerous from base. Leaves not rosulate, somewhat fleshy, petiolate; petioles of basal and lowermost leaves 1 -4(-9) cm long, gradually shorter upward; leaf blade suborbicular to subcordate or ovate to oblong, (0.5-)1.0-2.5 x (0.4-)0.7-2.0 cm, gradually reduced in size upward, base obtuse to subcordate, margin entire or rarely repand, apex obtuse or rounded. Racemes densely flowered, elongated considerably in fruit, bracteate throughout; bracts leafy and representing all cauline leaves; lowermost flowers near stem base. Sepals oblong, 0.8-1.5(-2.0) x 0.5-0.8(-1.0) mm, persistent or caducous shortly after fruit maturation, membranous at margin. Petals white, obovate, (1.5-)2.0-2.5(-3.0) x (0.5-)0.8-1.5 mm, cuneate to a clawlike base less than 0.5 mm long, apex rounded to slightly emarginate. Filaments white, 0.8-1.2 mm long, inner pairs distinctly dilated and to 0.3 mm wide at base; anthers ovate, 0.2-0.3 mm long. Ovules 3-5(or 6) per locule. Fruiting pedicels glabrous, slender, strongly recurved or nearly forming a loop, (3-)5-8(-12) mm long. Fruit narrowly conical, strongly torulose, slightly to strongly angustiseptate at least basally, (4-)7-10(-12) mm long, base cordate to truncate and (1.8-)2.0-2.5(-3.0) mm wide, apex acuminate; valves membranous, sparsely puberulent with papillae to 0.3 mm long, rarely subglabrous, distinctly veined; replum broadly expanded at base, narrowly flattened elsewhere; septum complete or rarely perforate and reduced to a rim, membranous; style slender, (0.5-)0.7-1.2(-1.5) mm long. Seeds 2-1 per locule, brown, oblong, foveolate, 1.4-1.8 x 0.8-1.2 mm; cotyledons incumbent or oblique.

Habitat and phenology: mountain meadows, forest margins, gravelly ridges, open slopes, roadsides; 2000-4000 m. Flowering June-August; fruiting July-September.

Distribution: China, Kazakstan, Kyrgyzstan, Mongolia, Russia, Tajikistan.

Specimens examined: CHINA. Gansu: Biandu Pass, Minle/Shandan Xian, Ho Tingnung 2731 (CAS). Xinjiang: Yecheng Xian, Qinghai-Tibet Expedition 870842 (KUN); Taxkorgan Xian, Kalaqigu, Wu Sugong, Wu Yuhu & Fei Yong 5079 (KUN, TI); Taxkorgan Xian, Qinghai-Tibet Expedition 870343 (KUN); Akto Xian, Wuyitage, Wu Sugong, Wu Yuhu & Fei Yong 5079 (KUN, TI); Akto Xian, Qinghai-Tibet Expedition 870123 (KUN); N slope of Tien Shan, 7.1 km E of Nan Shan Forest Station, Morfield et al. 5193 (MO); above Urumuqi, Guo Ronglin 78-82 (NAS);

Tian Shan, Cheo Taiyin 651209 (KUN); Hejin Fannaisi, Wu Zhengyi 394 (KUN).

KAZAKSTAN. Dshungari Alatau, Mt. Sauttau, near Kojschi, Goloskokov 5763 (BM, E, K, LE, MO, US); Road to Glacier Tuik Soo, above Almaty, Al-Shehbaz 9235 (MO); Alatau ad fontes fl. Lepsa, Karelin & Kiriloff 1216 (K, LE).

KYRGYZSTAN. Tersky Alatau, Gorge Chon Kyzil-su, 26 June 1949, Sobolev s.n. (MO); Kashgaria, Kara Teke, 7 June 1889, Roborosky s.n. (K, LE); Tien Shan Mt., valley of Ala Kol glacial lake, 8-30 Aug. 1995, Jewell s. n. (B M).

MONGOLIA. Altai, Politoff's.n. (K, LE).

TAJIKISTAN. Pamir, Aksu (Murgab), Alexeenko 2598 (BM, LE); Pamir, 1908, Appelton sm. (K); Kumbel, 31 May 1879, Regel sm. (K, LE); Altynemal, 24 Aug. 1878, Regel sm. (BM, LE).

The septum is complete in all except one of the collections examined. In Qinghai-Tibet Expedition 870842 (KUN) the septum is reduced to a very narrow rim at the distal and middle part of the fruit, and it connects the two sides of the replum only at the proximal part of the fruit. Although the fruit base is cordate in the majority of specimens, it is uncommonly truncate. The sepals vary from being persistent to caducous and from sparsely pubescent with flattened trichomes to glabrous. The fruit valves are often very sparsely puberulent along the valves and rarely are they completely glabrous. However, none of the variants seem to warrant formal recognition.

2. Taphrospermum himalaicum (Hook. f. & Thomson) Al-Shehbaz, Arai & H. Ohba, comb. nov.

Basionym: Cochlearia himalaica Hook. f. & Thomson, J. Linn. Soc., Bot. 5:154. 1861. TYPE: INDIA. Sikkim, 14,000-16,000 ft, June 25, J. D. Hooker s.n. (Holotype: K; Isotypes: B, P).

Herbs (2-)5-10(-15) cm tall, glabrous throughout except for sparsely puberulent fruit and distal portion of calyx. Root narrowly fu siform-linear, fleshy, apex with minute scalelike leaves. Stems solitary from fleshy root then producing a rosette with prostrate or rarely ascending to erect branches. Leaves not rosulate; petioles of basal and lowermost leaves (0.5-)1.0-2.5(-4.0) cm long, gradually shorter upward; leaf blade broadly ovate to oblong, 4-10(-15) x 2-6(-10) mm, gradually reduced in size upward, base obtuse to subcordate, margin lobed or toothed to repand or entire, apex obtuse or rounded. Racemes densely flowered, elongated considerably or not elongated in fruit, bracteate throughout; bracts leafy and representing all cauline leaves. Sepals oblong, 1.2-2.0 x 0.8-1.0 mm, persistent, membranous at margin, sparsely hairy distally. Petals white, obovate to spatulate, 2.5-4.0(-6.0) x 1.5-2.5 (-3.5) mm, attenuate to base, apex slightly emarginate. Filaments white, 1.5-2.0 mm long, median dilated at base; anthers ovate, 0.2-0.4 mm long. Ovules 4-12 per ovary. Fruiting pedicels glabrous, slender, straight or strongly recurved, and fruits appearing geocarpic, 4-9(-13) mm long. Fruit ovoid to oblong, latiseptate, not torulose, (2-)4-8(-10) x (1.5-) 2.0-3.4(-4.0) mm, obtuse at both ends; valves membranous, sparsely puberulent with papillae to 0.5 mm long, rarely subglabrous, obscurely veined; replum broadly expanded throughout; septum absent; style slender, 0.5-1.0(-1.2) mm long. Seeds (2-)6-8(-12), brown, oblong, foveolate, 1.0-1.5 x 0.8-1.0 mm; cotyledons obliquely accumbent.

Habitat and phenology: rocky ground on exposed slope, scree, deep rich soil, muddy slopes, stream banks, sandy beds, moist granite ledges, alpine pastures and dwarf scrub, Kobresia turf, under Juniperus trees; 3600-5200 m. Flowering June-September; fruiting July-October.

Distribution: Bhutan, China, India, Nepal.

Specimens examined: BHUTAN. Upper Mo Chu District, S slope of Yale La, 27 47' N, 89 27' E, Sinclair & Long 5500 (E); Dole La, Cooper 4050 (BM, E); Linqshi, Cooper 1620 (BM, E).

CHINA. Qinghai: Nangqen Man, ca. 30 km W of Nangqen along Xiao-qu River in Xiao-long Gou, 32 15' 21" N, 96 19' 23" E, Boufford, Donoghue, Lu & Ying 26549 (A, MO). Xi zang (Tibet): Upper Yi'ong Zangbo, near Lhari, above Tschama Yumco, 30 38' N, 93 12' E, G. & S. Miehe 95-08-l8, 95-l2-20 (GOET); Dengqen-Baqen, E side of pass SendoGyarubtang, 31 42' N, 94 58' E, Dickore 9196 (GOET); Tsangpo tributary, upper Nijiang/Gyamda Chu, Min La N slope, 127 km W Gongbogyamda, 29 50' N, 92 19' E, Dickore 5900 (GOET); Nyainqentanglha Shan, Yangbajain-Damxung, NW of Lhasa, valley SE of Nyaingwntanglha Feng, 30 19' N, 90 36' E, Dickore 3814, 3913 (GOET); Kyi Chu basin,

NE of Lhasa, above Reting Monastery, 30 18' N, 91 31' E, G. & S. Miehe 95-45-05 (GOET); Nedong, Lhunze, Upper Subansiri, TsangpoSubansiri Pass, 2838' N, 92 13' E, Dickore 9939 (GOET); Upper Gyamda Chu (Nyang Chu), W of Gongbogyamda, 2952' N, 92 17' E, Miehe & Wundisch 94-256-57 (GOET); Gyamda, 30 O 1' N, 93 07' E, Kingdon-Ward 12,266 (BM); hills N of Lhasa, Ludlow & Sherriff 8754 (BM, E); near Lhasa, Richardson /94 (BM); Reting, 60 miles N of Lhasa, Ludlow & Sherriff 11034 (BM, E); Kongbo, Shaga dzong, Ludlow & Sherriff 14174 (BM, E).

INDIA. Assam: Luguthang, 27 32' N, 92 I 1' E, Kingdon-Ward 11628 (BM).

NEPAL. Sagarmatha Zone, Solukhumbu Distr., around Khare, 27 46' N, 86 12' E, Miyamota, Amano, Ikeda, Joshi, Arai & Komatsu 9592227 (MO, TI).

Young plants of Taphrospermum himalaicum can easily be confused with Pegaeophyton nepalense Al-Shehbaz, Arai & H. Ohba. However, the latter is always scapose with flowers originating individually from the rosette, and it has globose fruits and often adaxially pubescent entire leaves. By contrast, T. himalaicum has flowers in bracteate racemes, oblong, slightly compressed fruits, and glabrous, dentate or lobed leaves.

One collection, Kingdon-Ward 12,266 (BM), has petals ca. 6 x 3.5 mm larger than other collections of the species. The plants are compact and produce numerous subrosulate leaves and numerous flowers in compact racemes not elongated in fruit. The fruits are on strongly reflexed pedicels and appear to be geocarpic. It is likely that the plant represents an infraspecific taxon of Taphrospermum himalaicum, but further collections are needed to verify this assumption. Similar compact habit with dense racemes not elongated in fruit is found in Sinclair & Long 5500 (E), but this collection has much smaller petals to 3 mm long.

3. Taphrospermum platypetalum Schrenk in Fischer & C. A. Meyer, Enum. Pl. Nov. 2: 60. 1842. TYPE: [KAZAKSTAN]. Dzungari Alatau, Mt. Dzhabyk, 23 July ? 1839, Schrenk .s.n. (Holotype: LE; Isotypes: K, LE).

Herbs 6-12 cm tall, glabrous throughout. Stems prostrate to erect, 1 to several from base. Leaves not rosulate, somewhat fleshy, petiolate; petioles of basal and lowermost leaves 0.5-2.0 cm long, gradually shorter upward; leaf blade

--104--

suborbicular to broadly ovate or oblong, 3-12 x 2-8 mm, gradually reduced in size upward, base obtuse to subcordate, margin entire, apex obtuse or rounded. Racemes densely flowered, elongated considerably in fruit, bracteate only on lowermost part. Sepals oblong, 1.5-2.2 x 1.0-1.2 mm, persistent, membranous at margin. Petals white, broadly obovate, 3.5-4.5 x 2.0-2.5 mm, cuneate to a clawlike base to 1 mm long, apex rounded. Filaments white, 1.1-1.4 mm long, dilated and to 0.3 mm wide at base; anthers ovate-oblong, 0.3-0.4 mm long. Ovules 2-4 per locule. Fruiting pedicels slender, straight, ascending to divaricate-ascending, 4-8 mm long. Fruit cylindric, strongly torulose, 6-11 mm long, widest at middle, ca. 1 mm wide, base cuneate, apex acuminate; valves thin papery, glabrous, somewhat veined; base of replum slightly expanded; style slender, 0.2-0.4 mm long. Seeds 2-4 per locule, reddish brown, oblong, foveolate, ca. 1.2 x 0.6 mm; cotyledons incumbent.

Distribution: endemic to Kazakstan.

Specimens examined: KAZAKSTAN. Songaria, Schrenk s.n. (P); Tarbagati Alatau, 1840, Schrenk s.n. (P).

The species is somewhat anomalous in Taphrospermum because it is glabrous throughout and with slender taproots, racemes bracteate only basally, and replums not broadly winged basally. Taphrospermum platypetalum is very poorly known and little collected species. It is likely to be found in adjacent Xinjiang (China).

4. Taphrospermum fontanum (Maximowicz) Al-Shehbaz & G. Yang, comb. nov.

Basionym: Dilophia fontana Maximowicz, Bull. Acad. St. Petersb. 26: 423. 1880. TYPE: CHINA. Gansu, Terra Tangutorum, 1-13 July 1872, Przewalski 202 (Holotype: LE; Isotype: PE).

Herbs (2-)5-14(-20) cm tall, sparsely to moderately pubescent, rarely glabrous. Root narrowly fusiform-linear, fleshy, base with minute scalelike leaves usually less than 2 mm long. Stems solitary from fleshy root then producing a few prostrate or rarely ascending to erect branches, sparsely to densely pubescent with retrorse to spreading trichomes to 0.5 mm long, rarely glabrous. Leaves not rosulate; petioles of basal and lowermost leaves (0.3-)0.6-2.0(-3.0) cm long, gradually shorter upward; leaf blade ovate to oblong, (2-)4-10(-13) x (1-)2-4(-7) mm, gradually reduced in size upward, base obtuse to cuneate, margin entire to obscurely dentate, apex obtuse or rounded. Racemes densely flowered, elongated slightly to considerably in fruit, bracteate throughout; bracts leafy, smaller than cauline leaves. Sepals oblong, 1.5-3.0 x 0.8-1.5 mm, persistent, membranous at margin, sparsely ciliolate near apex with trichomes ca. 0.05 mm long, sparsely hairy distally with trichomes to 0.5 mm long. Petals white or lavender, obovate to spatulate, 2-6 x (0.5-)0.7-3.50.0) mm, attenuate to base, apex slightly emarginate. Filaments white to lavender, 1.5-3 mm long, dilated at base; anthers ovate, 0.3-0.4 mm long. Ovules 4-8 per ovary. Fruiting pedicels glabrous or pubescent adaxially, slender, straight or curved, (1.5-)3.0-10.0(-20.0) mm long. Fruit broadly to narrowly obcordate, strongly to slightly angustiseptate, not torulose, (2-)3-5 x (4-)5-7 mm, obtuse to cuneate at base; valves membranous, sparsely to densely puberulent with trichomes to 0.5 mm long, rarely subglabrous, often distinctly veined, smooth or tuberculate; replum broadly and evenly expanded throughout; septum absent; style slender, (1-)2-3 mm long. Seeds 3-8, brown, oblong, foveolate, compressed, 1.2-2.2 x 0.8-1.5 mm; cotyledons accumbent.

KEY TO THE SUBSPECIES OF TAPHROSPERMUM FONTANUM

1. Petals 4.5-6.0 x 2.5-3.5(-4.0) mm; fruit valves glabrous or sparsely puberulent, smooth, not tuberculate; seeds (I .5-) I .8-2.2 x (I. I-)1.2-1.5 mm 4a. subsp. fontanum

1. Petals 2-3 x (0.5-)0.7-1.2(-l.4) mm; fruit valves densely or rarely sparsely puberulent, often tuberculate; seeds 1.2-1.6 x 0.8-1.1 mm 4b. subsp. microspermum

4a. Taphrospermum fontanum subsp. fontanum

Synonym: Dilophia macrosperma O. E. Schulz in W. Limpricht, Repert. Sp. Nov. Regni Veg. Beih. 12: 385. 1922. TYPE: CHINA. Tibet. Batang-Litang, PungtschamuTaschu, 5260 m, 22 August 1914, W.

Limprich 2235 (Lectotype, here designated: WRSL, n. v.; Isolectotype: WU).

Sepals 2.5-3.0 mm long; petals 4.5-6.0 mm long, 2.5-3.50.0) mm wide; filaments 2.5-3.0 mm long. Fruit valves glabrous or sparsely puberulent, smooth and not tuberculate. Seeds 3 or 4 per fruit, (1.5-)1.8-2.2 mm long, (1.1 )1.2-1.5 mm wide.

Habitat and phenology: damp shingle by rivers, alpine permafrost swamps, moist turf, open gravel, slate and schist scree; (3200-)3600-5300 m. Flowering June to September, fruiting July to October.

Distribution: endemic to China.

Specimens examined: CHINA. Gansu: La Chang K'ou, near Sining, Ching 636 (E, GH, US); Da-Lunq, Farrer & Purdom F643 (E); shingle of Wolvesden Beck, Farrer & Purdom F506 (E), Farrer & Purdom F599 (E); Tangut, Przewalski 636 (LE, PE), Przewalski s.n. (K, LE, P). Qinghai: Huzhu Xian, Yellow Plateau Team 5511 (MO); Chindu Xian, Xioqu Xiang, Xia Saiba, E of Chumda, 33 0' N, 97 20' E, Ho, Bartholomew, Watson & Gilbert 1891 (CAS, E, HNWP, MO); Tangula Shan N, upper Yangtze basin, Bi Qu, W of WenquanYanshiping (Mt. Geladandong), 33 33' N, 91 50' E, Dickore 4238 (MO). Sichuan: upper Yalong basin, Chola Shan, Dege-Garze, Manigango, 31 52' N, 99 07' E, G. & S. Miehe & Wiindisch 94-407-I (GOET); Hsioeh-shan, 3245' N, 10330' E, Smith 3836 (UPS). Xizang: Amnyi Machen range, W of Yellow River, Mt. Druggu, Rock 14414 (E, GH, K); without locality, 1884, Przewalski s.n. (K, LE).

In his original description of Dilophia macrosperma, Schulz (1922) distinguished the species from D. fbntana on the basis of having larger petals and fewer and larger seeds. It appears that he did not examine typical material of D. fontana because the types of the two are basically indistinguishable. Therefore, Kuan (1987) and Wang (1987) were correct in treating the two taxa as conspecific.

Wang (1987) cited several collections from Sichuan, but I have not seen them in connection with this study. He also cited one collection from Xizang, Tibet Chinese Medicine Expedition 4455 (PE), but that collection is cited below as subsp. microspermum.

4b. Taphrospermum fontanum subsp. microspermum Al-Shehbaz & G. Yang, subsp. nov. TYPE: CHINA. Qinghai: Maqin Xian, Ehema, Dawn Xiang, along Gequ He, S of Maqin on road to Gande, 30 July 1993, 34 20' 43" N, 100 15' 18" E, Ho, Bartholomew & Gilbert 570 (Holotype: MO; Isotypes: BM, CAS, HNWP).

Dilophia fontana Maxim. var. trichocarpa W. T. Wang, Acta Bot. Yunnan. 9: 3. 1987. TYPE: CHINA. Xizang, Amda, 4750 m, 14 August 1963, Yang Jinxiang 2222a (Holotype: PE).

Petala 2-3 mm longa, (0.5-)0.7-1.2 (-1.4) mm lata; valvae dense puberulae; semina 1.2-1.6 mm longa, 0.8-1.1 mm lata.

Sepals 1.5-2.0 mm long; petals 2-3 mm long, (0.5-)0.7-1.2(-1.4) mm wide; filaments 1.5-2.0 mm long. Fruit valves densely or rarely sparsely puberulent, often tuberculate. Seeds 2-8 per fruit, 1.2-1.6 mm long, 0.8-1.1 mm wide.

Habitat and phenology: disturbed alpine meadows, degraded alpine pastures, Kobresia turf and cushions, slopes with dwarf bushes; 3900-5000 m. Flowering July to August, fruiting late July to September.

Distribution: endemic to China.

Specimens examined: CHINA. Qinghai: Dari (Darlag) Xian, Mobadong Shan, Deang Xiang between Dari and Banma (Baima), 33 22' 37" N, 100 17' 24" E, Ho, Bartholomew & Gilbert 1246 (CAS); Gande Man, Gande Shan, Shanggongma Xiang, road from Dari to Gande, 3355' 46" N, 9944' 36" E, Ho, Bartholomew & Gilbert 888 (BM, CAS, HNWP, MO); Tangula Shan, Upper Yangtse basin, Bi Qu, Wenquan-Yanshiping (Lhasa-Golmud rd.), 33 31' N, 91 58' E, Dickore 4172 (MO); Qumarleb Xian, 1 August 1978, Cui Haiting s.n. (KUN); Lanchai Xiang, Tongren Man, Liu Shangwu 1488 (CAS); Zadoi, Liu Shangwu 235 (HNWP). Xinjiang: Tian Shan, Cheo Taiyien et al. 651283 (NAS). Xizang: alpine region between Radja and Jupar, meadows above Woti, Rock 14398 (E, GH, K, NY); upper Salween basin, Naqqu-Dengqen, pass W of Sog Xian, 31 55' N, 93 20' E, G. & S. Miehe & Wundisch 94-293-9 (MO); Lang Xian, Tibet Chinese Medicine Expedition 4455 (PE); Qamdo Xian, Wu 4780 (KUN), Amdo Man, Yang Jinxiang 2221 (KUN); Nyainqentangula Shan, N of Damxung, 30 39' N, 91 05' E, G. & S. Miehe 9495-15 (GOET); Tangula Shan S, Taoer Jiu Yakou, Little Tangula pass, 32 33' N, 91 51' E, Dickore 4128 (GOET, MO); Mt. Mnen Kor, Ladygin 109 (LE); Dzagyn Gol, Ladygin 171 (LE); upper Mekong basin, Mekong-Zi Qu divide, Qamdo-Riwoqe, NE of pass, 31 08' N, 96 54' E, Dickore 9072 (GOET).

Because of the fragmentary nature of the type of Dilophia fontana var. trichocarpa, we favored describing the taxon as a new subspecies with better type collection rather than raising the variety to a subspecies.

Although there is some overlap in the geographical ranges of the two subspecies of Taphrospermum fontanum, no intermediates have been seen in the material examined. Without detailed field work, it is not possible to determine the degree of overlap and whether or not the two subspecies hybridize.

5. Taphrospermum verticillatum (Jeffrey & W. W. Smith) Al-Shehbaz, comb. nov.

Basionym: Cardamine verticillata Jeffrey & W. W. Smith, Notes Roy. Bot. Gard. Edinburgh 8: 120. 1913. TYPE: CHINA. NW Yunnan, near Atuntsi, 15,000 ft, July 191 1, F. Kingdon-Ward 17 (Holotype: E). Synonyms: Braya verticillata (Jeffrey & W. W. Smith) W. W. Smith, Notes Roy. Bot. Gard. Edinburgh 11: 202. 1920; Staintoniella verticillata (Jeffrey & W. W. Smith) H. Hara, J. Jap. Bot 49: 198. 1974.

Herbs (4-)6-15(-23) cm tall, sparsely to moderately pubescent, rarely glabrous. Root narrowly fusiform-linear, fleshy, base with oblong to ovate scalelike leaves 3-7 x 1.0-2.5 mm. Stems erect, often solitary from fleshy root, lowermost leafless part (0.5-)4.0-10.0(-15.0) cm long. Leaves glabrous, lowermost cauline leaves verticillate, others opposite or alternate; petioles (0.4-)0.6-2.0 cm long, gradually shorter upward; leaf blade oblong, rarely oblanceolate, 0.5-1.5(-2.5) cm x 2-7(-9) mm, gradually reduced in size upward, base obtuse to rarely attenuate, margin entire, apex rounded. Racemes densely flowered, elongated considerably in fruit, bracteate throughout; bracts leafy, smaller than cauline leaves; rachis sparsely pubescent with retrorse trichomes 0.4-0.6 mm long. Sepals oblong, 2.5-3.5(-4.0) x 1.5-2.0 mm, caducous, membranous at margin, sparsely ciliolate near apex with trichomes 0.05-0.10 mm long, glabrous or sparsely hairy distally with trichomes to 0.5 mm long. Petals white or rarely lavender, broadly obovate, (7-)8-9(-10) x (3.5-)4.5-6.0 mm, cuneate to clawlike base to 4 mm long, apex emarginate. Filaments white to lavender, (3.0-)3.5-4.5 mm long, dilated at base; anthers ovate, 0.6-0.8 mm

long. Ovules 4-8 per ovary. Fruiting pedicels glabrous, slender, straight or curved, (4-)6-12(-18) mm long. Fruit ovate to oblong, strongly latiseptate, not torulose, 7-13 x 4-7 mm, obtuse to cuneate at base; valves membranous, glabrous, often distinctly veined, smooth; replum broadly and evenly expanded throughout; septum absent; style slender, (1-)2-3 mm long. Seeds 3-8, brown, oblong, foveolate, compressed, 1.8-2.2 x 1.2-1.4 mm; cotyledons accumbent.

Habitat and phenology: scree and ledges of cliffs, glaciers, open stony moorland, siliceous scree slopes; 3800-5200 m. Flowering June-July; fruiting July-August.

Distribution: endemic to China.

Specimens examined: CHINA. Xizang: Sarong, on Ka-gwr-pw, Mekong-Salween Divide, 28 25' N, Forrest 14490 (E, K, P, US, W); Nagarze-Lhozak, Glacier Vy, SE of Pomo Co, 28 26' N 90 35' E, Dickore 9515 (MO). Yunnan: Bei-ma Shan, 28 12' N, Forrest 13968 (E, K, P, W); Bei-ma Shan, 28 18' N 99 10' E, Forrest 19586 (BM, E, K, P, US, W); Diqing Prefecture, Deqin County, Bai Ma Shan, 28 23' N 99 O1' E, AldM, Alexander, Long, McBeath, Noltie & Watson 777, 940 (E); Beima Shan, 28 22' N 99 02' E, Alpine Garden Society Expedition 724 (K); Deqen Xian, T. T. Yii 9110 (A, KUN), Qinghai-Tibet Expedition 2756 (KUN); Nagala, Tsa-wa-rung, C. W. Wang 66067 (A); Zhongdian-Deqen, Hengduan Shan, Yangtze-Mekong divide, E of Deqen pass (rd. km 1903), 28 22' N 99 01' E, Dickore 14402 (MO).

The generic placement of Taphrospermum verticillatum has been controversial. Although the species was described originally as a doubtful member of Cardamine, as its authors correctly indicated that "the whorled leaves and the bracts are against its inclusion in that genus, but in the absence of fruit the affinity is doubtful." Smith (1920) transferred the species to Braya, but it was associated with B. sinensis Hemsely (now in Pegaeophyton Hayek & Hand.-Mazz.) and B. uniflora Hook. & Thomson (now in Pycnoplinthus O. E. Schulz). Schulz (1924) correctly excluded the species from Braya, but he did not assign it to any other genus. Finally, Hara (1974) placed the species in Staintoniella, but as discussed above and in Al-Shehbaz (2000), the species is most closely related to the following.

6. Taphrospermum lowndesii (H. Hara) Al-Shehbaz, comb. nov.

Basionym: Glaribraya lowndesii H. Hara, J. Jap. Bot. 53: 136. 1978. TYPE: NEPAL. Khangsar, 28 July 1950, 16,500 ft, D. G. Lowndes 1287 (Holotype: BM).

Herbs 5-12 cm tall, glabrous throughout or puberulent with papillae 0.05-0.20 mm long. Root slender, slightly fleshy, base with a crown of oblong scalelike leaves ca. 2-5 x 0.5-1.0 mm. Stems erect, 1-3 from root, lowermost leafless part 2-9 cm long. Leaves glabrous, fleshy, lowermost cauline ones verticillate, others alternate; petioles 2-5 mm long, gradually shorter upward; leaf blade spatulate, 3-15 x 1-5 mm, gradually reduced in size upward, base attenuate, margin entire, apex retuse or rounded. Racemes densely flowered, elongated considerably in fruit, bracteate throughout; bracts leafy, smaller than cauline leaves; rachis glabrous or papillate. Sepals oblong, 1.5-2.5 x ca. 1 mm, persistent well after fruit dehiscence, membranous at distal margin and apex, not ciliolate, glabrous or papillate. Petals white, narrowly obovate, 3-5 x 1.5-2.0 mm, attenuate to clawlike base to 1.5 mm long, apex obtuse. Filaments white, 1.5-2.5 mm long; anthers broadly ovate, 0.2-0.3 mm long. Ovules 4-6 per ovary. Fruiting pedicels glabrous, slender, straight or curved, 4-8 mm long. Fruit oblong or narrowly so, strongly latiseptate, not torulose, 7-15 x 3-5 mm, obtuse to cuneate at base; valves membranous, glabrous, often distinctly veined, smooth; replum broadly and evenly expanded throughout; septum complete, membranous; style slender, (1-)2-3 mm long. Seeds 3-8, brown, oblong, compressed, 1.9-2.1 x 1.2-1.4 mm, densely papillate with papillae 0.1-0.2 mm long; cotyledons accumbent.

Habitat and phenology: scree slopes and ledges of cliffs, glaciers, open stony moorland, siliceous scree; 5000-5200 m. Flowering July; fruiting July-August.

Distribution: China, Nepal.

Specimens examined: CHINA. Xizang: above Gyirong, MW of Mt. Xixabangma, 28 56' N, 85 24' E, G. & S. Miehe 9561/01 (GOET, MO).

Taphrospermum lowndesii is most closely related to T. verticillatum, both of which have lowermost stem leaves verticillate, compressed fruits, petiolate and entire stem leaves, and lowndesii differs from T. verticillatum in having persistent nonciliolate sepals, papillate seeds, smaller petals 3.0-3.5 x 1.5-2.0 mm, and septate fruits. By contrast, T. verticillatum has caducous and often ciliolate sepals, foveolate seeds, larger petals (7-)8-9(-10) x (3.5-)4.5-6.0 mm, and eseptate fruits.

Taphrospermum lowndesii is herein reported for the first time from China. The specimen cited above has fully mature fruits and was initially thought to represent an undescribed species. However, a closer comparison with the type revealed that they are conspecific. The type has immature fruits either papillate or completely glabrous, as in the Chinese material.

7. Taphrospermum tibeticum (O. E. Schulz) Al-Shehbaz, comb. nov.

Basionym: Dipoma tibeticum O. E. Schulz, Repert. Sp. Nov. Regni Veg. 38: 32. 1935. TYPE: CHINA. Tibet, 20 m E of Tsona, 16,500 feet, 20 July 1934, among stones, F. Ludlow do G. Sherriff 695 (Holotype: B; Isotype: BM).

Herbs 4-12 cm tall, densely hirsute with simple trichomes 0.5-1.0 mm long. Root conical, slightly fleshy, base with a crown of oblong scalelike leaves to 5 x 2 mm. Stems erect, 1-3 from fleshy root, lowermost leafless part 1-9 cm long, glabrous underground. Leaves densely hirsute on both surfaces and petiole, not fleshy, lowermost cauline ones verticillate to alternate, others opposite or alternate; petioles 3-5 mm long, gradually shorter upward, densely hirsute; leaf blade oblong to spatulate, 4-7 x 1-3 mm, gradually reduced in size upward, base attenuate, margin entire or repand, apex retuse. Racemes densely flowered, elongated slightly in fruit, bracteate throughout; bracts leafy, smaller than cauline leaves, hirsute; rachis retrorsely to spreading hirsute. Sepals oblong, 1.7-2.5 x 1.0-1.5 mm, membranous at distal margin and apex, ciliolate with trichomes to 0.1 mm long, densely hirsute outside with trichomes ca. 0.5 mm long. Petals white, broadly obovate, 4.5-5.0 x 2.5-3.0 mm, attenuate to clawlike base to 1.5 mm long, apex emarginate. Filaments white, 2.0-2.5 mm long, slightly dilated at base; anthers broadly ovate, ca. 0.5 mm long. Ovary ovoid, densely puberulent throughout; ovules 4-6 per ovary. Fruiting pedicels hirsute, slender, straight, 3-6 mm long. Immature fruit ovate, apparently latiseptate; valves membranous, densely puberulent; replum broadly and evenly expanded throughout; septum absent; style subconical, 1.0-1.5 mm long. Immature seeds oblong, ca. 1 mm long, foveolate.

Habitat and phenology: stony slopes, turf, earth slides, shale along streamside; 4200-5000 m. Flowering June-July; fruiting not observed.

Distribution: endemic to China.

Specimens examined: CHINA. Xizang: Tulung La, to Pen La, 27 49' N, 92 14' E, Kingdon-Ward 11,696 (BM); Le La, Chayul Charme road, Ludlow & Sherriff 1563 (BM).

Although initially described in Dipoma, Taphrospermum tibeticum is most closely related to T. verticillatum and T. lowndesii. It is readily distinguished from these by being densely hirsute throughout with trichomes 0.5-1.0 mm long, instead of glabrous or sparsely puberulent with papillae 0.05-0.20 mm long. From T. verticillatum it also differs by having smaller petals 4.5-5.0 x 2.5-3.0 mm and densely puberulent ovaries, instead of larger petals (7-)8-9(-10) x (3.5-)4.5-6.0 mm and glabrous ovaries. From T. lowndesii it also differs in having ovate instead of narrowly oblong fruits.

ACKNOWLEDGMENTS

I am grateful to Qin Haining (PE); Sun Hang (KUN); Xia Nianhe (IBSC): Pete Lowry (MO at P); Brigitte Zimmer (B); Mark Watson (E); Michael G. Gilbert (MO at BM); Simon Owens and Sue T. Zmarzty (K); H. Ohba (TI); S. Akiyama (TNS); W. Till (WU); and Rudolf V. Kamelin, Vladimir I. Dorofeev, Dimitry V. Geltman, Olga Cherneyva, Marina Novoselova, and Alicia Grabovitskaya (LE) for their enormous help during my visits to their herbaria. 1 am thankful to Zhu Guanghua, Yang Guang, and Song Hong for translating Chinese text and herbarium labels, and to Tatiana Shulkina for translating the Russian literature. I am most grateful to Hideaki Ohba for allowing me to study his collections from Qinghai, Xinjiang, and Tibet, as well as to B. Dickore and G. and S. Miehe for sending their Tibetan collections and duplicates for my study. Thanks also to K. Arai for his help during my study of the collections at TI. I thank the directors and curators of the herbaria cited in this paper.

LITERATURE CITED

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