Parasenegalia rurrenabaqueana (Rusby) Seigler & Ebinger, 2017

Seigler, David S., Ebinger, John E., Riggins, Chance W., Terra, Vanessa & Miller, Joseph T., 2017, Parasenegalia and Pseudosenegalia (Fabaceae): New Genera of the Mimosoideae, Novon 25, pp. 180-205 : 187-189

3. Parasenegalia rurrenabaqueana (Rusby) Seigler & Ebinger , comb. nov. Basionym: Acacia rurrenabaqueana Rusby, Mem. New York Bot. Gard. 7: 255. 1927. Senegalia rurrenabaqueana (Rusby) Seigler & Ebinger in Seigler et al. , Phytologia 88(1): 72. 2006. TYPE: Bolivia. Beni: Rurrenabaque , 1000 ft., 25 Jan. 1922, O. E. White 2043 (holotype, NY! [barcode] NY00001544 ; isotypes, GH!, K not seen, US! [bc] US00000606, US01014372) . Figure 4 .

Climbing shrub or small tree to 6 m tall; bark not seen; twigs light reddish to yellowish brown, not flexuous, terete, puberulent; short shoots absent; prickles absent. Leaves alternate, 60–200 mm long; stipules dark brown, linear, symmetrical, flattened, straight, herbaceous, 2.5–7.5 mm long, 0.2–0.4 mm wide near the base, pubescent, tardily deciduous; petiole adaxially grooved, 18–35 mm long, densely puberulent; petiolar gland solitary, located on the upper half of the petiole commonly near the lowermost pinna pair, sessile, oval to orbicular, 0.8–2.2 mm across, apex flattened to shallowly cupshaped, glabrous; rachis adaxially grooved, 40–170 mm long, usually densely puberulent, an oval gland 0.8–1.8 mm across between the uppermost 1 to 2 pinna pairs, apex flattened to depressed, glabrous; pinnae 6 to 9 pairs/leaf, 55–95 mm long, 8–17 mm between pinna pairs; paraphyllidia 0.5–1.1 mm long; petiolule 2–4 mm long; leaflets 13 to 30 pairs/pinna, opposite, 2.5–4.5 mm between leaflet pairs, oblong, 7–15 X 2.3–5.5 mm, appressed pubescent below and sometimes above, lateral veins obvious, 2 to 4 veins from the base, base oblique, truncate on one side, margins ciliate, apex narrowly acute to acuminate, midvein submarginal. Inflorescence a densely 15- to 35-flowered globose head 6.5–10 mm across, in terminal pseudopaniculate clusters, the main axis to 450 mm long; peduncles 2–12 X 0.3–0.5 mm, densely puberulent; receptacle not enlarged, slightly elongated; involucre 1 to 2 small bracts scattered along the upper half of the peduncle, early deciduous; floral bracts spatulate, 0.3–0.8 mm long, puberulent, early deciduous. Flowers sessile, creamy white; calyx 5-lobed, 0.9–1.6 mm long, puberulent; corolla 5-lobed, 1.7–2.4 mm long, puberulent, lobes 1/3 the length of the corolla; stamens 40 to 80; stamen filaments 4–5.5 mm long, distinct; anther glands present; ovary glabrous, the stipe to 0.6 mm long. Legumes straight, flattened, not constricted between the seeds, oblong, 90–180 X 22–35 mm, chartaceous, transverse striate, lightly appressed pubescent, eglandular, dehiscent along both sutures; stipe 6–15 mm long; apex obtuse, beaked; seeds uniseriate, no pulp, light to dark brown, nearly oval, strongly flattened, 6.5–8.5 X 5.5–7.5 mm, smooth; pleurogram U-shaped, 1.5–2.5 mm across.

Habitat and distribution. Parasenegalia rurrenabaqueana has been collected from dry semi-deciduous forests and seasonally flooded savannas, disturbed second-growth forest, and thickets from near sea level to 700 m in Bolivia and Peru.

Phenology. Parasenegalia rurrenabaqueana flowers from November through March.

IUCN Red List category. Parasenegalia rurrenabaqueana is assessed as Data Deficient (DD) at this time ( IUCN, 2001). This species is relatively common in Bolivia and Peru, suggesting that the species may be of Least Concern (LC).

Discussion. Parasenegalia rurrenabaqueana , P. visco , and P. santosii are restricted to South America. The ranges of the first two species overlap geographically, but P. rurrenabaqueana is found below 700 m, whereas P. visco is found at higher elevations, between 750 and 3000 m. These two taxa are easily separated, as P. visco has smaller leaflets (3–7 X 0.8– 2.1 mm) with a bluish midvein, while P. rurrenabaqueana has large leaflets (7–15 X 2.3–5.5 mm) and the midvein is not bluish purple. Parasenegalia santosii is only found in northeastern Brazil.

Specimens examined. BOLIVIA. Beni: Carretera Yucumo-Rurrenabaque, 235 m, 20–25 June 1989, D. N. Smith, M. Buddensiek & V. Garcıá 13577 (MO, US). La Paz: Abel Iturralde, San Buenaventura, 190 m, 16 Dec. 2003, A. Fuentes 6164 (ILL, MO); Guanay, 1800 ft., 14–16 Apr. 1926, G. H. H. Tate 571 (NY). Santa Cruz: 5.5 km NE of Cotoca, 340 m, 28 Nov. 19 90, M. Nee 40046 (MO, NY); 13 km NE of Cotoca, 325 m, 18 Dec. 19 92, M. Nee 43143 (MO, NY); 7 km NW of Puerto Pailas, 300 m, 10 Feb. 1994, M. Nee 44848 (MO, NY); 2.5 km NW of La Esperanza, 270 m, 26 Dec. 1997, M. Nee 47532 (ILL, MO, NY); 8.2 km NE of La Esperanza, 265 m, 26 Dec. 1997, M. Nee 47541 (ILL, MO, NY); 8.2 km NE of La Esperanza, 265 m, 26 Dec. 1997, M. Nee 47545 (ILL, MO, NY); Puente Las Chacras on the Montero-Okinawa hwy., 275 m, 26 Dec. 1997, M. Nee 47552 (ILL, MO, NY); Puente El Empalme, 10 km WSW of Colonia Okinawa, 250 m, 11 Jan. 1998, M. Nee 47916 (ILL, MO, NY); Parque Nacional Amboro, 400 m, 22 Jan. 1988, M. Nee & M. Saldias P. 36054 (MO, NY); Nuflo de Chavez, near San Julian, 274 m, 27 Feb. 2003, L. Rico, T. Windsor- Shaw, A. McRobb, L. Arroyo & C. Roth 1406 (MO); Nuflo de Chavez, near San Julian, 370 m, 27 Feb. 2003, L. Rico, T. Windsor-Shaw, A. McRobb, L. Arroyo & C. Roth 1413 (MO, NY). PERU. Amazonas: 14–15 km E of Bagua Chica on rd. to La Peca, 680–730 m, 12 June 1978, A. Gentry, M. Dillon, J. Aronson & G. Diaz 22 838 (F, MO). Loreto: Ivita, Km. 59, Pucallpa–Tingo Maria rd., 25 Mar. 1977, A. Gentry, J. Revilla, D. A. Castaneda & D. Daly 18604 (MO); Fortaleza, near Yurimaguas, 140 m, Nov. 1932, G. Klug 2784 (MO, NY, US). Madre de Dios: Parque Nacional del Manú, 350 m, 26 Aug. 1984, R. Foster 9918 (MO, NY); 350 m, Vargas 18656 (MO). San Martín: Juan Jui, Alto Río Huallaga, 400–800 m, Dec. 1935, G. Klug 4196 (F, MO, NY, US); Alto Rıó Huallaga, 360–900 m, Dec. 1929, L. Williams 6788 (F); Tarapoto, Dec. 1902, E. Ule 6623 (HBG). Ucayali: Lago de Yarinacocha, 250 m, 27 Mar. 1981, R. Vasquez & N. Jaramillo 1513 (ILL, MO).

Figures

Figure 4. Parasenegalia rurrenabaqueana (Rusby) Seigler & Ebinger. —A. Portion of pseudopaniculate cluster. —B. Leaf, adaxial view. —C. Petiolar gland. —D. Fruit. —E. Flower. —F. Leaflet, abaxial view. A, D, E from Nee 40046 (NY); B, C, F from Nee 47545 (ILL).