Hilsenbergia darcyana J.S. Mill., 2003

Miller, James S., 2003, Classification of Boraginaceae subfam. Ehretioideae: Resurrection of the genus Hilsenbergia Tausch ex Meisn., Adansonia (3) 25 (2), pp. 151-189 : 171-173

7. Hilsenbergia darcyana J.S. Mill. , sp. nov.

Arbor usque ad 6(-15) m alta, cortice exfoliante, ramunculis glabris. Folia decidua, alterna, lamina lanceolata usque anguste-elliptica vel ovata , 5-10 cm longa, 1.5-4.8 cm lata, apice acuminata , basi asymmetrice cuneata vel acuta usque obtusa , margine integra plerumque minute revoluata, adaxialiter glabra vel raro puberula secus costam, abaxialiter glabra vel puberula; petiolo 2-28(-45) mm longo. Inflorescentiae terminale, cymosae, usque ad 3(-5) cm latae. Flores bisexuales; calyce campanulato, 4.5-5 mm longo, 5-lobo, extus glabro, intus sericeo; corolla alba , urceolata , 6-6.5 mm longa. Fructus drupaceus, luteus , globosus, 11-13(-17) mm longus, 10-15(-20) mm in diam.; pyrenis 4, alatis.

TYPUS. — Seyrig 5404, Madagascar, Prov. Toliara, environs d’Ampandrandava , entre Bekily et Tsivory, 1000-1100 m, 24°05’S, 45°42’E, fl., s.d. (holo-, P!).

Tree to 6(-15) m tall, to 30 cm dbh, the bark exfoliating, the twigs glabrous, waxy. Leaves deciduous, alternate; blades lanceolate to narrowly elliptic or ovate, widest near or below the middle, 5-10 cm long, 1.5-4.8 cm wide, the apex acuminate, the base assymetrically cuneate or acute to obtuse, the margin entire and usually minutely revolute, the adaxial surface glabrous, or rarely puberulent along the midrib, the abaxial surface glabrous or rarely evenly puberulent, the venation brochidodromous, the midrib impressed or even with the adaxial surface, raised on the abaxial surface, the secondary veins 5-8, the tertiary venation reticulate; petioles 8-28(-45) mm long, glabrous or rarely sparsely puberulent, narrowly canaliculate on the abaxial surface.

Inflorescences terminal, cymose, to 3(-5) cm broad, the branches glabrous. Flowers bisexual; calyx campanulate, 4.5-5 mm long, the 5 lobes deltate, 2-2.5 mm long, acute at the apex, glabrous on the outer surface, sericeous on the inside of the lobes; corolla white, urceolate, 6- 6.5 mm long, the tube 4.5-5 mm long, the 5 lobes depressed-ovate, c. 1.5 mm long, 3 mm wide; stamens 5, the filaments 4-4.5 mm long, only the upper c. 1 mm free, the anthers borne near the mouth of the corolla, obloid, c. 1 mm long; ovary ovoid, c. 2 mm long, 1.5 mm wide, the style c. 2 mm long, not divided, the 2 stigmas capitate.

Fruits drupaceous, yellow at maturity, borne in the 6-8(-10) mm broad persistent calyx, globose, 11-13(-17) mm long, 10-15(-20) mm in diameter, the endocarp bony, separating into 4 pyrenes at maturity, these 7-10(-15) mm long, 4-6(-10) mm wide, with parallel papery wings on the outer surface. — Fig. 9 .

Hilsenbergia darcyana is largely a southern species that occurs at middle elevations, from 500-1200 m. In this respect, SF28596, from 100-200 m near Italy in the vicinity of Ft. Dauphin is unusual in occurring at such low elevation. The two most northern collections, Decary 14445, from Mandritsara, and RN7202, from the Réserve Naturelle de Bemaraha near Soalala, are also somewhat anomalous in their distribution but are included here as they are similar in most morphological features. They do, however, differ in having larger fruits (12-17 × 15-20 mm), compared with southern populations (11-13 × 10-15 mm). The collection from Mandritsara is outstanding also in having leaves that are wider in proportion to length and a puberulent undersurface. The southern populations of this species are quite consistent morphologically and easily recognized from H. bosseri , the only large-fruited species in the south, by their larger, acuminate leaves.

Hilsenbergia darcyana is named in honor of William G. D’ARCY (1931-2000), who spent his botanical career at the Missouri Botanical Garden and was a leading authority on the taxonomy of Solanaceae . He collected in Madagascar in 1983 and 1987 and published the treatment of Solanaceae for the Flore de Madagascar et des Comores with Armand RAKOTOZAFY in 1994.

DISTRIBUTION. — Hilsenbergia darcyana is known from upland sites from southern Madagascar ( Fig. 6 ).

VERNACULAR NAMES. — Behodiky, Lamoty Tsokaka.

CONSERVATION STATUS. — Provisional IUCN Red List Category: Endangered (EN B2ab(i-iv)). Hilsenbergia darcyana occurs over a wide range in Madagascar, but its populations are restricted to widespread upland sites that are effectively islands, thus limiting its Extent of Occurrence to 60 km 2. It does occur in protected areas in the Zombitsy reserve and possibly Andohahela and Isalo National Parks but it has not been collected for 35 years.

PARATYPES. — MADAGASCAR: Decary 14448, Prov .

Mahajanga, Mandritsara , 400-600 m, 15°50’S ,

48°50’E, fr., 20 July 1939 ( MO!, P!); Humbert 13422, Prov. Toliara, vallée de la Sakamalio, affluent de la Manambolo, bassin de Mandrare, 900-1100 m , 24°32’S, 46°41’E, fr., Dec. 1933 ( P!); Humbert 13831, Prov. Toliara, bassin de réception de la Mananara, affluent du Mandrare, pentes occidentales des montagnes entre l’Andohahela et l’Elakelaka, Mt. Apiky au-dessus de Mahamavo, 800-900 m , 24°55’S, 46°32’E, fr., Jan.-Feb. 1934 ( P!); Humbert, Begue & Capuron 29631, Prov. Toliara, forêt de Zombitsy, Sakaraha , aux confins des bassins du Fiherenana et de l’Onilahy, forêt tropophile sur sables siliceux de l’Isalo, 600-850 m , 22°46’S, 44°43’E, fr., 26-29 Mar. 1955 ( MO!, P!); Réserves Naturelles: RN7202 (Ramaroson), Prov. Mahajanga, Antsalova , 18°39’S, 44°37’E, fr., May 1955 ( P!); Service Forestier: SF4611 , Prov. Fianarantsoa, route Ihosy-Farafangana , 22°32’S, 46°29’E, fr., 20 Mar. 1952 ( P!, TEF!); Service Forestier : SF11930 bis (Capuron), Prov. Toliara, forêt de Zombitsy, à l’est de Sakaraha , 22°46’S, 44 o 43’E, fr., Mar. 1955 ( MO!, P!, TEF!); Service Forestier: SF28596 (Capuron), Prov. Toliara, colline gneissique au NE d’Italy, à l’ouest de Fort Dauphin , 100-200 m , 25°09’S, 45°46’E, fr., 15 Dec. 1968 ( MO!, P!, TEF!); Seyrig 295, Prov. Toliara, environs d’Ampandrandava, entre Bekily et Tsivory, 1000-1100 m , 24°05’S, 45°42’E, fr., Nov. 1945 ( P!) .

Figures

Fig. 9. — Hilsenbergia darcyana J.S. Mill.: A, flowering branch; B, whole flower with urceolate corolla; C, flower with open corolla showing androecium and gynoecium; D, lateral view of fruit with persistent calyx; E, basal view of fruit with persistent calyx; F, dorsal view of pyrene. A-C, Herb. Jard. Botanique 5404; D-E, Service Forestier: SF11930bis. Drawn by A. JOUY.

Fig. 6. — Distributions of Hilsenbergia species, mapped on the simplified bioclimate zones of Madagascar (after CORNET 1974; see SCHATZ 2000).