Asketanthera longiflora Woodson

Morales, J. Francisco, 2018, Studies in Neotropical Apocynaceae LIV: a synopsis of Asketanthera, Candollea 73 (1), pp. 7-17 : 12-13

3. Asketanthera longiflora Woodson in Ann. Missouri Bot. Gard. 19: 47. 1932 ( Fig. 3 , 4 ).

Ξ Echites longiflorus Ekman & Helwig in Ark. Bot. 22A(10): 45. 1929 [non E. longiflorus Desf. ].

Ξ Asketanthera ekmaniana Woodson, Ann. Missouri Bot. Gard. 23: 267. 1936 [nom. illeg. superfl.].

Lectotypus (designated here): DOMINICAN REPUBLIC. Prov. Barahona: Santo Domingo, cordillera de Bahoruco, sierra de los Cornincuios , between Beueve and Gros Figuier, near Vrickets, 28.VIII.1926, fl., Ekman 6762 ( S [ S04-1837 ]!; isolecto -: JE [fragment]!).

Branchlets sparsely puberulent to glabrate; interpetiolar colleters up to 1.4 mm long. Petioles 4-8 mm long; leaf blades 7.5-13.1 × 3-6.8 cm, ovate, ovate-elliptic to elliptic, the apex acuminate, the base obtuse, glabrous on the adaxial surface, sparsely puberulent to glabrate on the abaxial surface, secondary veins impressed on both surfaces. Inflorescence very sparsely puberulent, 2-4-flowered, peduncle 10-28 mm long, pedicels 10-22(-25) mm long, bracts 9-20 × 1.5-4 mm, linearelliptic, linear-ovate, narrowly ovate to narrowly elliptic; sepals 16-24 × 5-7 mm, narrowly ovate to ovate-elliptic, the apex shortly acuminate, glabrate externally, the colleter irregularly erose at the apex. Corolla green, inconspicuously puberulent to glabrate, the indument more dense in floral buds, tube 63-80 × 3.5-7 mm, inflated around the stamens, 6-7 mm diam. at the orifice; lobes 60-90 × 22-25 mm, obliquely elliptic; stamens inserted in the proximal half of the corolla tube, anthers 11-14 mm long, the auricles obtuse, style-head 3-4 mm long; ovary 3-4 mm long, glabrous; nectaries c. half of the ovary length, irregularly lobed. Follicles 18.5-20 cm × 3.5-5 mm, free, sparsely puberulent to glabrate, continuous; seeds unknown.

Distribution, habitat and phenology. – Endemic to Hispaniola ( Dominican Republic and Haiti), growing in wet forest over limestone hills from 1000-1300 m. Flowering in August and September. Fruits have been reported in November.

Conservation status. – This species is known from only four localities in Hispaniola with an EOO of 865 km 2 and an AOO of 16 km 2, from regions with highly disturbed and fragmented forest remnants. Three of the specimens were collected more than 90 years ago, but future fieldwork could probably reveal additional populations. Asketanthera longiflora is provisionally assessed as “Endangered” [ENB1ab(iv) + B2ab(iii,iv)] following IUCN Red List Categories and Criteria ( IUCN, 2012).

Notes. – Asketanthera longiflora is easily recognized by its 2-4-flowered inflorescences and the corolla tube 63-80 mm length. WOODSON (1936) described 2-8-flowered inflorescences, but in all the specimens examined (included those examined by Woodson) the inflorescence has up to 4 flowers. The duplicate of Ekman 6762 at S is designated here as the lectotype. One duplicate is deposited at JE, but it is a fragment, whereas a second duplicate at B was destroyed in 1943.

Specimens examined. – HAITI. Dept. Sud: eastern La Hotte, Chapelle Mont Carmel, 8.XI.1924, fr., Ekman 2426 ( S); massif de la Hotte, eastern group, St. Grave, near Chap St. Mickel, steeps, limestone hillside, 4.VIII.1926, fl., Ekman 6598 ( S).

DOMINICAN REPUBLIC. Prov. Pedernales: 50 km de la Compañía de Exploración Alcoa, Puerto Cabo Rojo, camino a las Mercedes and Las Abejas, área llamada Las Abejas, 15.IX.1981, fl., Zanoni & Mejía 16561 (CR, MO, NY).

Figures

Fig. 3. – Distribution map of the four accepted species in Asketanthera Woodson.

Fig. 4. – Asketanthera longiflora Woodson. A. Habit; B. Adaxial view of one sepal, showing the colleter at the base; C. Anther, dorsal view; D. Nectaries and ovary;E. Style-head. F. Follicles.