Philibertia woodii H.A. Keller & Goyder, 2021

Keller, Héctor A. & Goyder, David J., 2021, A new species of Philibertia (Apocynaceae) from Bolivia, Darwiniana, nueva serie 9 (2), pp. 293-298 : 294-297

Philibertia woodii H.A. Keller & Goyder spec. nov. ( Fig. 1 y 2 )

TYPE: Cochabamba: Prov. Mizque, c. 25 km S of Totora towards Río Mizque, fl. 19/01/1997, J.R.I. Wood 11682 (holotype K.; isotypes BOLV, LPB).

Philibertia speciosa (Malme) Goyder affinis sed corolae tubo et retinaculo brevioris; affinis P. latiflora sed corolae tubo intus glabris.

Scrambling plant, stems several meters long, latex white, stems tomentose to glabrescent, with simple eglandular white or yellowish trichomes, 0.1-1 mm long, uniseriate, multiseptate, the longest patent, the shortest curved; robust floriferous branches, 3-5 mm in diameter, with dense yellowish pubescence, internodes 4-22 cm long. Leaves opposite; petiole 1-7 cm, with pubescence similar to that of the branches; lamina ovate to ovatelanceolate, 5-11(-20) x 2-6(-11) cm, discolorous, adaxial surface pubescent, with trichomes simple, appressed, antrorse; abaxial surface lanate; margin entire, apex acuminate, base cordate to auriculate, with 3-5 finger-like colleters on the adaxial face, hidden under the trichomes, venation brochidodromous with 7-11 pairs of secondary veins. Inflorescences extra-axillary corymbiform, alternate, with 2-6(-8) flowers; peduncles 2-5.5 cm long, lanate, trichomes yellowish; bracts filiform to oblong-lanceolate, pubescent, 3-3.5 x 0.2-0.5 mm; pedicels 0.8-1.5-6 cm long; calyx divided to near base; tube 0.3-0.35 mm high; lobes lanceolate, 5-8 x 1.5-2 mm, acute, pubescent on both sides, with 3-5 conical colleters in the sinus 0.05-0.15 mm long; corolla with urceolate or campanulate tube, 0.6-1 x 0.5-0.6 cm, somewhat inflated at the base or not, external surface densely pubescent, internal surface glabrous, lobes yellow, cream or white, sometimes white with a yellow tube, lobes lanceolate 1-1.8 x 0.5-0.7 cm, twisted, densely pubescent below, glabrous above; gynostegial and corolline corona lobes absent; gynostegium subsessile 0.6 x 0.3 cm; anthers rectangular 4 x 2 mm, anther wings 3-3.5 mm long, apical membrane oblong-ovate, 1.7-2.2 x 1.1- 1.2 mm; stylar head appendage conical to filiform, extendingbeyondthemembranousantherappendage for (1.5-)2.5-3.5(-6) mm, apically bifurcated into two segments 0.1-0.2(-1) mm long; corpusculum oblong-lanceolate, 1.4-2 x 0.25-0.35 mm, apex acute, caudicles horizontal 0.30-0.35 mm long, reddish, widened near the insertion of pollinia, pollinia oblong in outline 1.05-1.15 x 0.25-0.60 mm; ovary ca. 4 x 1.6 mm, with trichomes at the apex of the carpels. Follicles (immature) ovoid, smooth, lanate. Seeds unknown.

Etymology. Species dedicated to John R. I. Wood, prominent collector of the Bolivian flora, who collected the largest number of specimens of the species.

Distribution and Habitat. Philibertia woodii is known at present from the inter-Andean dry valleys of Bolivia in Cochabamba, Chuquisaca and Tarija, where it grows in scrub on bare rock slopes, in river canyons, or at the margins of moist Tucumán-Bolivian forest. The populations in Cochabamba appear to be in drier scrub vegetation than those encountered in Chuquisaca and Tarija. Altitude 1300-2800 m.

Phenology. Found with flowers and immature fruits from December to March.

Taxonomic observations. Of the four species in the genus with large flowers with a well-developed stylar head appendage and lacking a corona, the new species is most similar to P. speciosa in various vegetative as well as floral characters. Both are lianas that reach several meters in length, with robust lanuginous branches, long petiolate leaves, with large discolored blades; in both the flowers have a yellow or white corolla with a welldeveloped tube ( Fig. 2A and B ) which is more or less urceolate or inflated at the base and pubescent only on the external face, the stylar head appendage is generally shorter than the gynostegium, the corpusculum is oblong-lanceolate more than 1 mm long, the caudicles are horizontal and the pollinia are oblong. On the other hand, P. longistyla has a homogeneous whitish to cream corolla ( Fig. 2C ), while in P. latiflora it is white with a yellow tube and throat, coloration that sometimes extends towards the central strip of the lobes ( Fig. 2D ). A single collection of the new species from the Totora region of Cochabamba has a cream or white corolla with a yellow throat. In addition, in these two last species ( P. longistyla and P. latiflora s. str.) the interior of the corolla tube is pubescent, the stylar head appendage exceeds the gynostegium in length, the retinaculum is shorter than 1 mm and the pollinia are not oblong.

P. woodii differs from P. speciosa by the corolla tube that is shorter; the stylar head appendages a little longer, exserted from the throat of the corolla, and the retinaculum much shorter.

The only Bolivian collection of P. latiflora s. str. that we have encountered is from the Narvaez valley on the decent from Tarija towards Entre Rios (J.R.I. Wood & Goyder 15845 (K, LPB)), not far from where Zuloaga et al. 10407 (SI) was collected. However, although it has a pubescent interior to the corolla tube, the length of the corpusculum (1.3 mm) is intermediate between that of typical P. latiflora and P. woodii , suggesting a possible hybrid zone in this area.

Specimens examined

Paratypes. Bolivia, Cochabamba: Prov. Mizque, c. 1 km below small church on ascent from Río Mizque to Totora , fl. 21-II-1998, J.R.I. Wood 13024 ( BOLV, K, LPB) ; 6 km above Mizque on road to Arani , fl. 9-III-1997, J.R.I. Wood 11850 ( K, LPB) ; First canyon c. 10-15 km NW of Mizque on road to Arani , fl. 25-II-2001, J.R.I. Wood 17149 ( K, LPB) ; Mizque , outside E of town, fl. 27-XII-2002, Rico & Windsor-Shaw 1173 ( K, LPB) ; Prov. Campero, c. 36 km from Pasorapa and 3-4 km before Buena Vista , fl. & fr. 24-III-2003, J.R.I. Wood et al. 19473 ( K, LPB, USZ) ; Prov. Carrasco, on road from Totora to Omereque , fl. 26-XII-2004, J.R.I. Wood et al. 21228 ( BOLV, K, LPB) ; 190 km from Sucre towards Aiquile , fl. 12- III-1965, Badcock 617 ( K) ; km 195 from Sucre to Cochabamba , fl. IV-1963, Cardenas 6081 ( K, US) . Chuquisaca: Prov. Tomina, c. 15 km E of Zudáñez towards Villa Tomina , fl. 31-XII-1994, J.R.I. Wood 9055 ( K, LPB) ; Tomina , 3 km S of San Pedro on road to Azurduy, fl. 13-II-1999, J.R.I. Wood & Serrano 14442 ( HSB, K, LPB) ; Prov. Azurduy, c. 25 km S of San Pedro on road to Azurduy , fl. & fr. 6-XII-1999, J.R.I. Wood, Goyder & Serrano 15342 ( HSB, K, LPB, NY) ; Prov. Zudáñez, bajando a la comunidad de Jacha Pampa del cerro, al este de Mojocoya , fl. 30-I-2005, J.R.I. Wood & Huaylla 21555 ( HSB, K, LPB) ; Prov. H. Siles, Serrania los Milagros , fl. 6-III-1995, Muñoz 123Z ( K, LPB) . Tarija: Prov. O’Connor, on first pass c. 10 km NE of Entre Ríos on road to Palos Blancos , fl. 17-I-2001, J.R.I. Wood & Goyder 16804 ( K, LPB) ; at beginning of ascent through forest by old road to Tarija , fl. 29-II-2016, J.R.I Wood et al. 28045 ( K, LPB, USZ) , Ruta 11 entre Narvaez y Entre Ríos , 1 km de Narvaez ; 21° 25’ 52’’ S, 64° 16’ 28’’ W. 24- II-2008, fl, Zuloaga et al. 10407 ( SI) .

Figures

Fig. 1. Philibertia woodii. A, floriferous node. B, flower in superior view. C, gynostegium. D, pollinarium. E, ovary. (Drawings by Héctor A. Keller, from Zuloaga et al. 10407).

Fig. 2. A, Philibertia woodii. B, P. speciosa. C, P. longistyla. D, P. latiflora. (Photos A, D: F. O. Zuloaga; B: Gustavo Hildt, C: D. Goyder). Color version at http://www.ojs.darwin.edu.ar/index.php/darwiniana/article/view/963/1228