Xerochlamys bojeriana (Baill.) Baker

Hong-Wa, Cynthia, 2009, Endemic families of Madagascar. XII. Resurrection and taxonomic revision of the genera Mediusella (Cavaco) Hutchinson and Xerochlamys Baker (Sarcolaenaceae), Adansonia (3) 31 (2), pp. 311-339 : 320-326

3. Xerochlamys bojeriana (Baill.) Baker

Journal of the Linnean Society, Botany 25: 296 (1889). —

Sarcolaena bojeriana Baill. , Adansonia 10: 177 (1872). —

Leptolaena bojeriana (Baill.) Cavaco, Mémoires de l’Institut

scientifique de Madagascar, sér. B, 4: 64 (1952). — Type:

Madagascar, without precise locality, date unknown, fl.,

Bojer s. n. (holo-, P! [P00389113]).

Xerochlamys pilosa Baker , Journal of Botany , British and Foreign 20: 45 (1882). — Type: Madagascar, on the top of a bleak stony hill in the west of the Betsileocountry, date unknown, fl., Baron 134 (holo-, K [image seen]; iso-, P! [ P00490727 ]).

Sarcolaena grandidieri Baill. , Bulletin de la Société linnéenne de Paris 1: 565 (1886). — Xerochlamys grandidieri (Baill.) Baker , Journal of the Linnean Society, Botany 25: 296 (1889). — Type: Madagascar, Prov. Fianarantsoa, Ambatomenaloha, [20°37’S, 46°33’E], 1876, fl., Grandidier 63 (holo-, P! [3 sheets: P00389114-16 ]).

Xerochlamys pubescens Baker , Journal of the Linnean Society , Botany 25: 296 (1889). — Type: Madagascar, Imerina , Lahavohitramountain,dateunknown,fr., Baron 5112 (holo-, K [image seen]; iso-, P! [2 sheets: P00389111-12 ]).

ADDITIONAL MATERIAL EXAMINED. — Madagascar. Prov.

Antananarivo, PK 36, route d’Antsirabe , [19°08’30’’S,

47°31’30’’E], 16.II.1966, Rakotozafy 457 ( TAN) . —

Ambatofotsy, [20°03’S, 47°05’E], 16.VII.1952, Service

Forestier 107-R-222 (P). — Ambatolampy , [19°22’S,

47°24’E], II.1953, Bosser 4828 ( TAN). — Ambohipo-

nana, [20°04’S, 47°03”E], 1500 m, 20.XI.1912, Viguier & Humbert 1416 (K, P). — Andramasina, [19°11’S, 47°35’E], II.1958, Descoings 3106 (MO, TAN). — Idem, croupe rocailleuse aride entre Ambohimasina et Andramasina, 3.XII.1912, Viguier & Humbert 1915 (MO, P). — Andrangaranga, [19°00’S, 47°08’E], 14.I.1964, Service Forestier 23206 (MO, P). — Idem, Service Forestier 23206bis (MO, P). — Ankaratra, [19°22’S, 47°15’E], 2250 m, 5.VIII.1989, Du Puy & Du Puy MB279 (TAN). — Idem, [19°20’S, 47°16’E], 1700-2200 m, 27.IV.1955, Humbert & Capuron 30301 (P). — Antongona, environs de Tananarive, [18°56’S, 47°16’E], I.1956, Bosser 8947 (MO, P, TAN). — Idem, 4.XII.1959, Peltier 1546 (P, TAN). — Antsirabe, 5 km of Antilarisona, north of Antsirabe, [19°51’S, 47°02’E], 1250-1300 m, 23.I.1975, Croat 29219 (K, MO, P). — Idem, [19°51’S, 47°02’E], IV.1912, Perrier de la Bâthie 3017 (P). — Arivonimano, [19°01’S, 47°11’E], 16.X.1992, Allorge 660 (P). — Idem, 29.I.1960, Peltier 1822 (P, TAN). — Idem, V.1956, Service Agricole 1088 (MO, TAN). — Idem, massif de l’Ambohitrambo, 24.X.1965, Service Forestier 24176bis (P, TEF). — Behenjy, [19°12’S, 47°29’E], 1400-1500 m, 12.I.1972, Cremers 1934 (TAN). — Idem, 11.V.1939, Decary 13897 (P). — Idem, rocher d’Iaranandriana, 10.III.1984, Dorr et al. 2886 (K, MO, P). — Idem, north of Behenjy on road from Antananarivo to Antsirabe, 12.I.1986, Dorr et al. 4571 (K, MO, P). — Idem, 12.II.1938, Herbier du Jardin Botanique de Tananarive 3172 (P). — Idem, Perrier de la Bâthie 14630 (P). — Idem, entre Behenjy et Ambatolampy, PK 51, 1400 m, 1.IX.1949, Service Forestier 647 (K, P, TEF). — Betafo, [19°50’S, 46°51’E], 19.XI.1912, Viguier & Humbert 1416 (K, P, TAN). — Between Miarinarivo and Antananarivo, PK 60, [19°00’S, 47°03’E], I.1958, Descoings 2897 (MO, TAN). — Faratsiho, [19°24’S, 46°57’E], IX.1921, Perrier de la Bâthie 13938 (P). — Iarinandriana, 40 km de Tananarive, [19°10’S, 47°30’E], IV.1957, Bosser 11062 (TAN). — Ibity, southwest slope of Mt. Kiboy, 20°03’50”S, 46°59’58”E, 1624 m, 27.I.2001, Birkinshaw et al. 816 (MO). — Idem, [20°07’S, 47°01’E], 22.VII.1989, Du Puy et al. MB271 (MO, P, TAN). — Idem, Mt. Kiboy, 20°03’52”S, 47°00’03”E, 1662 m, 1.XI.2001, Hong-Wa et al. 1 (MO, P, TAN, TEF). — Idem, 1552 m, 20. VI.2005, Hong-Wa et al. 321 (MO, P, TAN). — Idem, [20°07’S, 47°01’E], 13.X.1970, Keraudren-Aymonin & Aymonin 24587 (P). — Idem, 20°03’47”S, 47°00’02”E, 1650 m, 16.II.1997, Lowry & Schatz 4814 (MO, P). — Idem, Ambohimanjaka, base est du Mt. Ibity, [19°45’S, 47°15’E], 1600 m, III.1920, Perrier de la Bâthie 13208 (P). — Idem, 1800 m, III.1921, Perrier de la Bâthie 13573 (P); Perrier de la Bâthie 13573bis (P). — 2000 m, IX.1921, Perrier de la Bâthie 13969 (P). — [20°07’S, 47°01’E], 1200 m, III.1928, Perrier de la Bâthie 18495 (P). — Idem, 20°04’10”S, 47°00’16”E, 1700 m, 17.II.2003, Schatz et al. 4126 (MO). — Itasy, PK 68, route Tananarive à l’Itasy, [18°57’S, 47°05’E], 11.XI.1970, Keraudren-Aymonin & Aymonin 25416 (P). — Manandona, versant droit de la basse Manandona, [20°03’S, 47°03’E], 1200-1800 m, V.1920, Perrier de la Bâthie 13165 (MO, P). — Manazary, [19°03’S, 46°52’E], 1300 m, 8.XII.1912, Viguier & Humbert 1956 (P). — Miarinarivo, [18°57’S, 46°54’E], VII.1912, Perrier de la Bâthie 3005 (P). — VI.1926, Perrier de la Bâthie 17610 (P). — [18°56’S, 46°51’E], 1200 m, III.1926, Perrier de la Bâthie 17615 (P). — Ramainandro, [19°18’S, 47°00’E], I.1955, Bosser 7558 (MO, P,TAN). — Sabotsy, [19°13’S, 47°36’E], II.1959, Bosser 12784 (MO, P, TAN). — Sahanivotry, PK 202 de la route Tananarive-Fianarantsoa, [20°07’S, 47°04’E], 1500 m, 9.II.1949, Service Forestier 230 (P, TEF). — Soamananety, 50 km west of Antananarivo, [18°59’S, 47°04’E], 1300-1400 m, 13.II.1985, Barnett et al. 459 (K, MO, P). — 27.I.1937, Chardon & Bigorgne s. n. (P). — 57 km west of Antananarivo, 9.I.1985, Dorr et al. 3436 (K, MO, P). — Idem, route Tananarive-Miarinarivo, PK 55, [18°58’S, 47°05’E], 1300 m, 14.XII.1989, Evrard 11300 (P, TAN). — Talata-Volonondry, [18°45’S, 47°41’E], VIII.1906, d’Alleizette 1265 (P). — Prov. Fianarantsoa, Ambandroja, [21°59’- 22°00’S, 46°36’-46- °37’E], 900-1360 m, 22.VII.1954, Service Forestier 14491 (P, TEF). — Ambasy, [21°28’S, 46°11’E], 1100 m, 9. XII.1974, Cremers 3581 (MO, P, TAN). — Ambatofinandrahana, 54 km east of Finandrohana, [20°35’S, 47°02’E], 1300 m, 25.I.1975, Croat 29670 (MO, P). — Idem, 18 km west of Finandrahana, 1100 m, 26.I.1975, Croat 29726 (MO). — Idem, [20°33’S, 46°48’E], 1600- 1800 m, 23.II.1938, Decary 13257 (P). — 3.II.1942, Decary 17289 (P); Decary 17358 (MO, P). — Idem, 7 km south-west of Ambatofinandrahana, on the route to Fenoarivo, 20°36’48”S, 46°49’31”E, 1300 m, 20.XI.1993, Du Puy et al. M627 (K, MO, P, TAN, TEF). — Ambatomenaloha, [20°37’S, 46°33’E], 1876, Grandidier 63 (P). — Ambohimanjaka, entre Antsirabe et Ambositra, [20°15’S, 47°06’E], 1500 m, 6.III.1985, Dorr et al. 3844 (K, MO, P). — Idem, 20°14’10”S, 47°05’59”E, 1500 m, 23.III.1999, Labat et al. 3009 (G, K, MO, P, TAN). — Ambositra, dans les bois de Tapia, [20°31’S, 47°15’E], 2.II.1942, Decary 17246 (P). — Ankijana, [20°37’S, 47°05’E], 5.II.1955, Service Forestier 13470 (P, TEF). — Col desTapia, route d’Ihosy àTuléar, [22°47’S, 45°01’E], 1000-1300 m, Aubréville s. n. (P). — Idem, a region of rocky wooded hills 48 km north of Ambositra, [20°15’S, 47°09’E], 1300-1400 m, 24.I.1975, Croat 29348 (MO, TAN). — Croat 29356 (MO, TAN) — Idem, Haute Sahatsio, 1600 m, 24.XII.1928, Humbert 7110 (K, P, TAN). — 20.VII.1928, Humbert & Swingle 4655 (P). — Idem, PK 200 entre Antsirabe et Ambositra, II.1960, Keraudren 104 (P). — Idem, près d’Ilaka, 1500 m, 26.X.1960, Léandri 3327 (P). — Idem, massif de l’Isalo, second col des Tapia, entre Ranohira et Sakaraha, [22°47’S, 45°01’E], 1000-1300 m, 21.XI.1960, Léandri & Saboureau 3962 (P). — Idem, premier col des Tapia, Ambositra, [20°15’S, 47°01’E], V.1969, Morat 3174 (TAN). — Faliarivo, [20°39’S, 47°07’E], 24.I.1956, Descoings 2036 (TAN). — 1600 m, III.1934, Humbert 14494 (P). — Humbert 14495 (MO, P). — 15.I.1955, Humbert & Capuron 28012 (MO, P). — Idem, lisières de la forêt de Faliarivo, 15.I.1955, Service Forestier 11546 (P, TEF). — Ilaka, [20°15’S, 47°09’E], 27.III.1952, Service Forestier 4632 (P, TEF). — Itremo, [20°34’21”S, 46°34’54”E], I.1964, Bosser 18876 (P, TAN). — Idem, montagnes à l’ouest d’Itremo, [20°35’S, 46°38’E], 1500- 1700 m, 17.I-22.IV.1955, Humbert 30021 (MO, P). — Idem, [20°32’S, 46°33’E], 1.XII.1970, Keraudren- Aymonin & Aymonin 25756 (P); Keraudren-Aymonin & Aymonin 25756bis (P); Keraudren-Aymonin & Aymonin 25780 (P); Keraudren-Aymonin & Aymonin 25784 (P). — Idem, eastern margin of the Itremo massif, c. 19 km west of Ambatofinanadrahana, 20°34’21”S, 46°3454”E, 1580 m, 11.III.2000, Schatz et al. 3982 ( MO); Schatz et al. 3985 ( MO). — Itremo , [20°32’S, 46°33’E] , 4.III.1955, Service Forestier 13994 ( MO, P, TEF). — Idem, aux environs du col de l’Itremo , [20°36’S, 46°34’E], 1600-1700 m , 27.XI.1969, Service Forestier 28895 ( P, TEF). — Ivato, 12 km à l’ouest d’Ivato, piste d’Ambatofinandrahana , [20°40’S, 47°08’E], VI .1969, Morat 3316 ( TAN). — Idem, 12 km à l’ouest d’Ivato, route de Morondava , XI.1970, Morat 3676 ( P, TAN). — Parc national d’Isalo , [22°11’S, 45°10’E] , 1.XI.1940, Decary 16335 ( P). — Idem, traversée de l’Isalo Nord, à l’est de Sahanafa , [22°19’S, 45°18’E], 1000 m , 28.XI-4.XII.1946, Humbert 19543 ( P). — Idem, à l’ouest de Ranohira , [22°11’S, 45°10’E], 800-1250 m , 29.I-2.II.1955, Humbert 29819 ( P). — 1000-1300 m , 19.XI.1960, Léandri & Saboureau 3933 ( P) . — 19.XI.1960, Réserves Naturelles 11222 ( P). — Ranomafana , 20°30’43”S, 46°46’31”E, 1475 m , 7.II.2001, Andriamihajarivo et al. 38 ( MO, TAN, TEF). — Andriamihajarivo et al. 39 ( MO, TAN). — Sahambano, PK 20, route de Ihosy à Ivohibe , [22°29’S, 46°16’E], V .1973, Morat 4254bis ( P, TAN). — Sahatsiho-Ambohimanjaka, entre Antsirabe et Ambositra , PK 202, [20°11’S, 47°05’E], 1400 m , IX.1956, Bosser 9967 ( MO, P, TAN). — Vatomitombo, au sud d’Antsirabe , [20°14’S, 47°06’E], 1800 m , 3.V .1961 , Service Forestier 23496 (K, MO, P, TEF). — Prov. Toamasina, Analarohy, au nord d’Andilamena , [16°48’S, 48°32’E], 1000 m, XI.1922, Perrier de la Bâthie 15006 ( P). — Mangoro , [18°53’S, 48°07’E], 800 m , VIII.1912, Perrier de la Bâthie 3003 ( P). — Tampoketsa d’Anosibe , [18°09’S, 49°23’E], 1500 m , 5.V .1967 , Service Forestier 26307 (P, TEF). — Without precise locality, Baron 947 (K, P); Baron 1873 (K, P); Baron 5119 (K, P). — 23.V .1931 , Basse s. n. (P). — 23.I .1975 , Croat 29208 (MO). — Le Myre de Vilers s. n. (P). — Perrier de la Bâthie 13606 (P).

DESCRIPTION Shrubs; young and older twigs pubescent. Leaf blades glossy dark green above, light green beneath, elliptic or occasionally ovate, 0.5-2.5 × 0.3-2 cm,

chartaceous to sometimes subcoriaceous, sparsely pubescent above, densely pubescent beneath, base rounded, margin plane, apex retuse or occasionally acute, midrib light brown, flat above, slightly raised beneath, secondary veins indistinct, 6-12 per side, 1-2.5 mm apart, looping 0.2-1 mm from the margin; petiole 0.7-3 mm long, pubescent. Flowers solitary or in inflorescences, terminal, with 2 flowers; peduncle 1-2 mm long, pubescent, pedicel 1-2 mm long, pubescent. Involucre brown, cupulate, 2-6 × 3-9 mm, with short brown tomentum interspersed with dense white trichomes, teeth 14-28, 0.4-2.4 mm long; flowers 11-22 mm long at anthesis from apex of pedicel to apex of petals; sepals oblong, 4-8 × 3-6 mm, deeply emarginate, exserted 2-4 mm beyond the involucre; petals pink fading to white, oblong, 9-22 × 4-9 mm, exceeding the involucre by 13-16 mm; disc 2-2.5 mm tall; stamens 25-35, 6.5-13 mm long; ovary globose, 3 mm high, style 6-13 mm long, pubescent, stigma 0.4-1.4 mm wide. Fruits globose to subglobose, 5-9 × 5-10 mm, exceeding the accrescent involucre by 4-7 mm; seeds brown, ovoid, 2-3 mm long, 2-11 per fruit.

PHENOLOGY

Flowering and fruiting all year round; peaking from September to April.

VERNACULAR NAMES

Hatsikana, Katikana.

HABITAT

Evergreen sclerophyllous Uapaca bojeri Baill. (tapia) woodland on various rocky substrates up to 2000 m elevation within the subhumid bioclimatic zone.

DISTRIBUTION

Central region of Madagascar from Miarinarivo- Arivonimamo to Isalo National Park ( Fig. 2 ).

REMARKS

Xerochlamys bojeriana can be recognized by its small (<3 cm long), elliptic to ovate leaf blades covered with sparse white trichomes on both surfaces, and its flowers with pink petals. This species differs from X. undulata by its short petiole (<3 mm long vs. 3-7 mm), the length to width ratio of the elliptic leaf blades (3:1 vs. 2:1), its plane (vs. undulate) leaf margin, and its pink (vs. pale yellow to white) flowers. Xerochlamys bojeriana can be distinguished from X. elliptica most easily by its having trichomes on the leaf blades (vs. entirely glabrous).

Previous authors such as Perrier de la Bâthie (1931) and Cavaco (1952a, b) circumscribed Xerochlamys bojeriana very broadly to include material assigned here to X. elliptica and X. undulata . The present circumscription includes the types of three previously described taxa: 1) Baron 134, the type of X. pilosa , has small (≤ 1 cm long) elliptic, pubescent leaf blades with acute apices; 2) Grandidier 63, the type of Sarcolaena grandidieri , whose leaf blades are ovate and more or less glabrous; and 3) Baron 5112, the type of X. pubescens , whose leaves are larger (≥ 2 cm long), ovate and pubescent. Although these types seem to represent distinct morphological forms and other collections can be associated with each one, there are also intermediates between them, and when taken together they form a coherent albeit variable group.

The specimen of Perrier de la Bâthie bearing the number 13988 has been reassigned the number 13938 based on information from the collector’s fieldbook, in which the number 13988 refers to a species of Angraecum Bory whereas 13938 refers to a species of Xerochlamys . Moreover, labels of the specimen bearing the number 13988 have been overwritten, adding further support for reassigning it to 13938 (P. B. Phillipson pers. comm.). Specimens of Perrier de la Bâthie 13989 cited by Cavaco (1952b) and referred to as Xerochlamys bojeriana have not been located and their identity remains uncertain.

CONSERVATION STATUS

With an extent of occurrence of 36 055 km2 and an area of occupancy of 2900 km 2, Xerochlamys bojeriana is provisionally considered to be Least Concern (LC) as it is widely distributed and occurs in many protected areas. However, the potential habitat of this species is locally threatened by mostly annual fires.

4. Xerochlamys coriacea Hong-Wa, sp. nov. ( Fig. 3 )

Arbuscula , foliis ellipticis pubinervis coriaceis ad apices obtusis et ad bases attenuatis, floribus axillaribus, involucro albo piloso 12-24 dentato, fructibus globosis polyspermis.

TYPUS. — Madagascar. Prov. Toliara, above Ankoba village, near east edge of Andohahela National Park , Parcel 1, transitional forest along ridge above village, 24°46’4’5’’ S, 46°43’17’’E, 675 m, 22. I.2008, fl., Lowry et al. 6966 (holo-, MO!; iso-, G, K, MO!, P!, TAN) .

PARATYPES. — Madagascar. Prov. Fianarantsoa, Malazarivo, [21°57’S, 46°36’E], 17.II.1955, Service Forestier 13769 ( K, P, TEF) . — Réserve naturelle intégrale d’Andringitra, [22°07’S, 46°46’E], 1200 m, IV.1921, Perrier de la Bâthie 13604 ( P) . — 26.XII.1952, Réserves Naturelles 4877 ( MO, P, TAN) . — 16. V.1955, Réserves Naturelles 7179 ( P, TEF) . — 23.XI.1955, Réserves Naturelles 7495 ( P, TEF) . — Prov. Toliara, Ampandrandava, [24°05’S, 45°41’E], 1100 m, I.1943, Herbier du Jardin Botanique de Tananarive 5823 ( P) . — IV.1943, Herbier du Jardin Botanique de Tananarive 6412 ( P) . — Idem, environs d’Ampandrandava, entre Bekily etTsivory, I.1943, Seyrig 454 ( P) . — IV.1943, Seyrig 454 B ( P) . — Analamary, proche du village Fenoarivo, [23°13’S, 45°50’E], 800 m, 22.X.1954, Service Forestier 12129 ( P, TEF) . — Bekily, [24°13’S, 45°19’E], 400 m, 14. I.1954, Service Forestier 8394 ( P, TEF) . — Imonty, bassin de réception de la Mananara, affluent du Mandrare, pentes occidentales des montagnes entre l’Andohahela et l’Elakelaka, [24°48’S, 46°41’E], 900-950 m, II.1934, Humbert 14098 ( P) . — Ivakoany, [23°49’S, 46°23’E], 12.IV.1954, Service Forestier 10200 ( P, TEF) . — Mahamavo, bassin de réception de la Mananara, affluent du Mandrare, pentes occidentales des montagnes entre l’Andohahela et l’Elakelaka, [24°45’S, 46°43’E], 450 m, I-II.1934, Humbert 13756 ( P) . — Mt. Vohitrosy, vallée moyenne du Mandrare près d’Anadabolava, [24°16’S, 46°43’E], 800-850 m, XII.1933, Humbert 12680 ( K, MO, P) . — Réserve naturelle intégrale d’Andohahela, [24°31’- 24°53’S, 46°37- 46°52’E], 6. I.1951, Réserves Naturelles 2759 ( MO, P, TAN) . — 7.VIII.1955, Réserves Naturelles 7476 ( P, TEF) . — Idem, sur la crête du Vataza, au sud-est d’Imonty, 16. I.1963, Service Forestier 22452 ( K, P, TEF) . — Vohidava, vallée moyenne du Mandrare près d’Anadabolava, [24°09’S, 46°15’E], 750-810 m, XII.1933, Humbert 12618 ( P) . — 6.XI.1963, Service Forestier 22599 ( P, TEF) . — Vohipola, au nord de Betroka, [23°08’S, 46°05’E], 1100-1300 m, XI.1933, Humbert 11633 ( P) .

DESCRIPTION

Trees 4-8 m tall, trunk to 20 cm dbh; young twigs slightly tomentose, older twigs glabrous. Leaf blades

light green above, darker green beneath, elliptic to narrowly ovate, 3-6 × 1-2 cm, coriaceous, rarely with trichomes on the abaxial midvein, base truncate to sometimes attenuate, margin irregularly undulate, apex obtuse to occasionally retuse, midrib green to yellowish, slightly raised above, distinctly raised beneath, secondary veins distinct, 7-12 per side, 2-6 mm apart, looping 0.5-2 mm from the margin; petiole 4-12 mm long, with sparse trichomes. Flowers solitary or in inflorescences, axillary, with 2 or 3 flowers; peduncle 1-2 mm long, glabrous, pedicel 1-2 mm long, glabrous. Involucre green, cupulate, 3-6 × 4-10 mm, brown tomentose when young with a few white trichomes, teeth 12-24, 0.8-2 mm long; flowers 19-30 mm long at anthesis from apex of pedicel to apex of petals; sepals obovate, 6-8 × 4-7 mm, slightly emarginate, exserted 2-5 mm beyond the involucre; petals white, obovate, 13-21 × 6-12 mm, exceeding the involucre by 10- 15 mm; disc 1.7-2 mm tall; stamens 18-42, 8.4- 19 mm long; ovary globose, 3-3.4 mm high, style 6.5-16.3 mm long, pubescent, stigma 0.5-1.5 mm wide. Fruits ovoid, 5-9 × 6-12.5 mm, exceeding the accrescent involucre by 2-6 mm; seeds brown, ellipsoid, 2-3 mm long, 3 or 4 per fruit.

PHENOLOGY

Flowering and fruiting from November to February.

VERNACULAR NAMES

Fotona, Hary, Kotika, Vandrozo.

HABITAT

In subhumid to dry forests and thickets, on metamorphic and igneous rocks from 450 to 1200 m, at the border of the subarid and humid, and in the subhumid bioclimatic zones.

DISTRIBUTION

From Andohahela to near Andringitra in SE Madagascar ( Fig. 2 ).

REMARKS

Xerochlamys coriacea is a small tree that can be recognized by its elliptic, coriaceous leaf blades borne on a long petiole (up to 12 mm). This species shows some variation in leaf size. Specimens from the northern part of its range (Andringitra) have larger leaf blades (> 4 cm long) than those from material collected toward its southern limits, which also have thicker leaves, possibly because this species grows in less humid habitats in the south. Perrier de la Bâthie also mentioned on the label of one of his collections (13604) that the larger leaves were from a fertile resprouting shoot. Despite this variation in leaf size, specimens assigned to X. coriacea form a coherent group with distinctive features that are also geographically correlated. Xerochlamys coriacea differs from X. villosa in particular by its smaller, elliptic, coriaceous (vs. ovate, chartaceous) leaf blades with irregularly undulate (vs. plane) margins, its inconspicuous (vs. prominent) secondary veins and its brown tomentose (vs. yellow tomentose) involucre bearing sparse white trichomes. Its leaves differ from those of X. tampoketsensis by the same characters and additionally by their truncate to attenuate (vs. rounded) base.

CONSERVATION STATUS

With an extent of occurrence of 22 006 km2, an area of occupancy of only 90 km 2, and nine subpopulations of which two are located within protected areas (Réserves naturelles intégrales d’Andohahela and Andringitra), Xerochlamys coriacea is assigned a preliminary status of Vulnerable [VU B2ab(i,ii,iii)].

Figures

FIG. 2. — Distributions of Xerochlamys bojeriana (Baill.) Baker (●) and X. coriacea Hong-Wa (★) mapped on the bioclimatic zones of Madagascar (after Cornet [1974], simplified by Schatz [2000]).

FIG. 3. — Xerochlamys coriacea Hong-Wa: A, leaf; B, flowering branch; C, flower buds; D, fruit with and without involucre. Humbert 12680. Scale bars: A, C, D, 5 mm; B, 1 cm.