Raputia codo-pozuzoensis Rob. Fernandez & Arteaga, 2017

Fernandez-Hilario, Robin & Arteaga, Robert, 2017, A new species of Raputia (Rutaceae) from the Selva Central of Peru, PhytoKeys 89, pp. 73-84 : 74-78

Raputia codo-pozuzoensis Rob. Fernandez & Arteaga sp. nov. Figure 1 , 2

Diagnosis.

Raputia codo-pozuzoensis differs from others species in this genus by its 5-7-foliolate leaves and longer petioles (8.5-12.5 cm long).

Type.

PERU. Huánuco: Prov. Puerto Inca, Dist. Codo de Pozuzo, alrededores de toma de agua cerca al Rio Pozuzo , 565 m, 9°40'57.76"S, 75°30'31.35"W, 01 Feb 2015 (fl.), R. Fernandez, R. Arteaga & F. Meza 830 (holotype MOL - 2 sheets) .

Description.

Monopodial shrub up to 2 m tall; stem cylindrical, 1-1.5 cm in diameter, lenticellate and finely ribbed, dark brown; the terminal buds, young twigs and petioles, and inflorescences pubescent, the hairs short and antrorse. Terminal twigs circular in transverse section, 4-7 mm in diameter, beige-colored when dry, lenticellate; terminal buds ferruginous, stipules absent. Leaves palmately compound, 5-7-foliolate, opposite or verticillate; petiole cylindrical, 8.5-12.5 cm long, 2-3 mm wide; petiolule absent; leaflet blades elliptical, acuminate at apex, decurrent at base, entire at margin, discolorous, sub-chartaceous, the venation brochidodromus, the surface pellucid-punctate, the upper and lower surface glabrous, midrib pubescent beneath, the hairs short and antrorse; central leaflet (21-) 25-36 cm long, 3.5-6 cm wide, the secondary veins (18-) 21-29; lateral leaflet progressively smaller, the basal ones (7.5-) 11-18 cm long, 1.7-3.5 cm wide, the secondary veins 10-16. Inflorescence cauline, of 1-3 monochasia, with 6-14 flowers, 1.8-3 cm long including a peduncle 2-5 mm long. Flowers bisexual, zygomorphic, pentamerous; pedicel 1.5-2 mm long; flower buds slightly curved. Calyx 4-4.5 mm long, 3.5 mm wide at base of lobes, glabrous or pubescent; sepals fused at the base, 5-lobed, the lobes quincuncial, ovate, acute to obtuse at apex, 2 mm long, ciliate, pellucid-punctate. Corolla tubular, unequally 5-lobed, 12-17.5 mm long, bilabiate at anthesis, glabrous in the external surface, sparsely pubescent in the inner base of the tube, woolly in the inner part of the throat, the trichomes ca. 1.2 mm long; the tube white to yellowish, 2-6 mm long to the sinuses of the innermost lobe (inferior lip), 6-9 mm long to the sinuses of the other 4 lobes (superior lip), recurved superior lip; the lobes green, imbricate, oblong, rounded at apex, the inner lobe 10-12 mm long, 3.5-5 mm wide, the other 4 lobes 5-6 mm long, 3.5-4.5 mm wide, pellucid-punctate. Androecium of 2 fertile stamens and 3 staminodia, white-colored; filaments of fertile stamens flanking the inner lobe, adherent from the base to the throat of the corolla tube, the free portion above the throat ca. 2 mm long; staminodia adherent from the base to the throat of the corolla tube, the free portion linear above the throat 9-11 mm long, alternate with the other four corolla lobes; filaments of fertile stamens and staminodia glabrous at the base and apex, only bearded at the throat of the corolla, filaments and back of anthers pellucid-punctate; anthers lanceolate, laterally coherent, basifixed, ca. 5.5 mm long, 1.5 mm wide, glabrous, the appendages flattened, ca. 1.5 mm long, 1 mm wide, glabrous. Gynoecium, ovary of 5 carpels united at the base and by single style, 1.5 mm in diameter, 1 mm high, furrowed, orange-colored; the style 10-11 mm long, slightly curved, glabrous, pellucid-punctate; the stigma 1 mm in diameter, slightly 5-lobed; disc cupular enveloping the ovary, 2.5 mm in diameter, 1.5 mm high, margin 5-lobed, cream-colored, glabrous. Fruit not seen.

Distribution and habitat.

Raputia codo-pozuzoensis is endemic to humid premontane forest in central Peru, between 565-589 m.a.s.l., growing in zones with shallow to steep slopes in a loamy-silty soil. The only known population of this species occurs in the understory of a forest of tree species, such as: Chrysophyllum sanguinolentum (Pierre) Baehni, Helicostylis scabra (J.F. Macbr.) C.C. Berg, Hevea guianensis Aubl., Iryanthera hostmannii (Benth.) Warb., Mabea speciosa Müll. Arg., Macrolobium gracile Spruce ex Benth., Theobroma subincanum Mart. and Virola pavonis (A. DC.) A.C. Sm.

Etymology.

The specific epithet refers to the Codo de Pozuzo district, the only place where the specimens were found and collected.

Phenology.

Flowering take place from December to February.

Conservation state.

We collected individuals of Raputia codo-pozuzoensis in areas of slightly disturbed forest, and we observed individuals sprouting after being cut for the establishment of " trochas " (pathways). We counted 20 individuals in an area of 0.5 ha. Thus, we assume that human activities are not affecting seriously the wild populations of this species. Nonetheless, in our inventories at other sites in Puerto Inca Province and surrounding areas, we and our collaborators have not observed other populations of this new species. Additionally, the extent of occurrence estimated of this species has been decreasing over the last years by deforestation and only remaining less than 100 km2 of the original forest cover. Therefore, under the guidelines of UICN (2012), we assign this species to the category Critically Endangered [CR (B1a+bi)].

Additional specimens examined.

PERU. Huánuco: Prov. Puerto Inca, Dist. Codo de Pozuzo, alrededores de toma de agua cerca al Rio Pozuzo , 589 m, 9°40'56.72"S, 75°30'30.85"W, 28 Dec 2015 (fl.), R. Fernandez & R. Arteaga 1079 (MOL), R. Fernandez & R. Arteaga 1080 (USM), R. Fernandez & R. Arteaga 1081 (HOXA) .

Discussion.

According to the morphologic analyses of Kubitzki et al. (2011), Raputia belongs to a natural group along with the following genera: Apocaulon R.S. Cowan, Decagonocarpus Engl., Ertela Adans., Lubaria Pittier, Ravenia Vell. and Raveniopsis Gleason, characterized by their opposite leaves (alternate in Apocaulon ), overlapping sepals, connate petals, basally appendaged (exc. in Ertela ) and often laterally coherent anthers, reticulate pollen grains, apocarpous gynoecia, and conduplicate, bilobed cotyledons. Among this group, the two herbaceous genera, Apocaulon and Ertela , stand out and differ noticeably from the others. The former, by its alternate leaves and anthers coherent by their adaxial surfaces, and the later by its strongly unequal sepals, with the two outer much larger and concealing the corolla, and the anthers lacking basal appendages. Previously, Kallunki (1994) recognized that Raputia was related with the following genera: Decagonocarpus , Lubaria , Ravenia and Raveniopsis , forming a group characterized by opposite leaves, a quincuncial calyx (of which the margins are conspicuously overlapping at anthesis), and conduplicate, bilobed cotyledons. Kallunki (1994) differentiated Raputia from these other four genera by the presence of cauline inflorescences and the leathery testa (vs. terminal inflorescences and crustaceous testa). Even though we did not register neither the seeds nor the fruits of Raputia codo-pozuzoensis , the combination of characteristics such as cauline inflorescences, the petals connate, forming a bilabiate corolla with a short tube, and anthers laterally connate, with basal appendages, allow us to locate this new species in the Raputia genus. In Table 1 we display the different characteristics of genera related to Raputia , according to Kubitzki et al. (2011).

Raputia codo-pozuzoensis is easily distiguished from all other species of the genus by its 5-7-foliolate palmately compound leaves. The other three species found in Peru show unifoliolate ( Raputia simulans ) or three-foliolate leaves ( R. hirsuta and R. megalantha ). Raputia codo-pozuzoensis differs further from R. simulans by its much shorter inflorescences 1.8-3 cm long (vs. 19.5-26.5 cm) and from Raputia hirsuta by its short and antrorse hairs (vs. hirsute) on stems, leaves, and inflorescences.

Like Raputia megalantha and Raputia maroana (R.S. Cowan) Kallunki, Raputia codo-pozuzoensis possesses inflorescences shorter than 6 cm and terminal leaflets longer than 20 cm. Raputia codo-pozuzoensis differs, however, from R. megalantha by its petioles 8.5-12.5 cm long (vs. 0.8-3.3 cm) and its corollas 12-17.5 mm long (vs. 30 mm). Although Raputia codo-pozuzoensis shares with R. maroana petioles and corollas of similar lengths, it differs from the latter by its 5-7-foliolate (vs. 3-foliolate) leaves and filaments ca. 2 mm (vs. 11-12 mm) long. In addition, Raputia codo-pozuzoensis is restricted to premontane forest in southwestern Amazonia (Huanuco, Peru), whereas R. megalantha and R. maroana are distributed in lowland forests in northwestern Amazonia (Brazil, Peru, and Venezuela; Kallunki, 1994).

Figures

Figure 1. Raputia codo-pozuzoensis. A Terminal twig B Midrib beneath and lower leaf surface C Inflorescences D Flower E Corolla opened showing two fertile stamens and staminodes F Longitudinal section of calyx, disc cupular, ovary and style. From R. Fernandez et al. 830 (MOL). Drawing by Sara Terreros.

Figure 2. Raputia codo-pozuzoensis. A Habit B Inflorescence (R. Fernandez & R. Arteaga 1079; MOL) C, D Flowers (R. Fernandez et al. 830; MOL). Photos by Robin Fernandez.