874 research outputs found
Senegalia galpinii Seigler & Ebinger 2010
No full textSenegalia galpinii (Burtt Davy) Seigler & Ebinger , C. W. Fagg 574 FHO, EU440000, EU811851, EU811968, EU812024Published as part of Miller, Joseph T. & Seigler, David, 2012, Evolutionary and taxonomic relationships of Acacia s. l. (Leguminosae: Mimosoideae), pp. 217-224 in Australian Systematic Botany 25 (3) on page 224, DOI: 10.1071/sb11042, http://zenodo.org/record/427814
Pseudosenegalia riograndensis Seigler & Ebinger 2017, comb nov.
No full text2. Pseudosenegalia riograndensis (Atahuachi & L. Rico) Seigler & Ebinger, comb nov. Basionym: Acacia riograndensis Atahuachi & L. Rico, Kew Bull. 62: 605. 2007. TYPE: Bolivia. Cochabamba: Prov. Campero, Pasorapa, en la bajada de Buenavista hacia el Rıo Grande, 1447 m, 27 Dec. 2004, J. R. I. Wood, M. Atahuachi & M. Mercado 21251 (holotype, BOLV; isotypes, K! [barcode] K 00503018, K! [bc] K 005033019, LPB [bc] LPB0 0 0 0 6 7 6, MEXU [bc] MEXU0128851). Figure 11. Tree to 12 m tall; bark nearly white, smooth to shallowly fissured; twigs orange to reddish brown, not flexuous, terete, glabrous; short shoots present at some nodes, 0.4–1 mm long, with a few leaves attached; prickles absent. Leaves alternate, also clustered at short shoots, 15–55 mm long; stipules light brown, linear, symmetrical, flattened, straight, herbaceous, 1–2.5 X 0.1–0.2 mm, glabrous, usually persistent; petiole adaxially grooved, 4–13 mm long, glabrous; petiolar gland solitary, located just below to nearly between the lowermost pinna pair, sessile; orbicular to oval, 0.4–1.1 mm across, apex depressed, glabrous, sometimes absent; rachis adaxially grooved, 5–40 mm long, glabrous, an orbicular gland 0.3–0.7 mm across between the uppermost 1 to 2 pinna pair, apex depressed, glabrous; pinnae 3 to 7 pairs/leaf, 9– 2 0 mm long, 3–1 2 mm between pinna pairs; paraphyllidia absent; petiolule 0.9–2.1 mm long; leaflets 12 to 26 pairs/pinna, opposite, 0.8–1.7 mm between leaflet pairs, linear, 1.2–2.9 X 0.5–0.9 mm, glabrous, lateral veins not obvious, 1 vein from the base, base oblique, truncate on one side, margins lightly ciliate, apex obtuse, midvein subcentral. Inflorescence a loosely 40- to 90-flowered cylindrical spike, 28–60 X 12–18 mm, solitary from the leaf axils; peduncles 5–16 X 0.3–0.8 mm, glabrous; receptacle not enlarged; involucre absent; floral bracts spatulate, 0.7–1.1 mm long, ciliate, persistent. Flowers sessile, white; calyx 5-lobed, 1.5–2.2 mm long, lightly puberulent; corolla 5-lobed, 3.5–6 mm long, glabrous to puberulent, lobes 1/5 the length of the corolla; stamens 100 to 140; stamen filaments 7.5–9.5 mm long, distinct; anther glands absent; ovary glabrous, stipe to 2.1 mm long. Legumes straight, flattened, not constricted between the seeds, oblong, 95–130 X 10–15 mm, coriaceous, transversely striated, glabrous, eglandular, dehiscent along both sutures; stipe 6–11 mm long; apex acute, short beaked; seeds uniseriate, with no pulp, light brown, ellipsoid, strongly flattened, 9–11 X 6–7 mm, smooth; pleurogram U-shaped, 3–5 mm across. Habitat and distribution. Pseudosenegalia riograndensis is known locally in seasonally dry tropical forest at about 1300 m in the Rio Grande valley below Pasorapa, Provence Campero, Cochabamba, Bolivia. Phenology. Pseudosenegalia riograndensis flowers from November through December. IUCN Red List category. Pseudosenegalia riograndensis is assessed as Data Deficient (DD) at this time (IUCN, 2001). This species is apparently rare and is only known from two collections, the type and one other from a restricted region in Bolivia suggesting that the species may at least be Vulnerable (VU), perhaps Endangered (EN). Specimen examined. BOLIVIA: Cochabamba: Campero, Bosque Termotropical inferior de Neocardenasia herzogiana y Schinopsis haenkeana, 1300 m, 24 Nov. 1999, C. Antezana 1325 (NY).Published as part of Seigler, David S., Ebinger, John E., Riggins, Chance W., Terra, Vanessa & Miller, Joseph T., 2017, Parasenegalia and Pseudosenegalia (Fabaceae): New Genera of the Mimosoideae, pp. 180-205 in Novon 25 on pages 201-203, DOI: 10.3417/2015050, http://zenodo.org/record/256146
Diverse pattern of strain at the Afar triple junction
No full textStrain and seismicity show us the mode by which deformation is accommodated in rifting continents. Here we present a combined analysis of InSAR derived strain maps and seismicity of the Afar triple junction from 2006 to 2010. Our analysis shows that that the plate spreading motion is accommodated in different modes. A dogbone-shaped seismicity and strain distribution dominates the northern branch of the triple junction, likely as a result of repeated dike intrusions 2005-2010. In the eastern branch strain is distributed across the central part of several overlapping rifts while seismicity appears decoupled from strain and it focuses at the rifts tips. A third branch shows a narrow and elongated zone of both high strain and seismicity. The pattern suggests that the history of magmatic intrusions and rifting events creates a diverse triple junction accommodation zone
Strain accommodation in transitional rifts: extension by magma intrusion and faulting in Ethiopian rift magmatic segments
No full textActive deformation within the northern part of the Main Ethiopian Rift (MER) occurs within approximately 60 km-long, 20 km-wide ‘magmatic segments’ that lie within the 80 km-wide rift valley. Geophysical data reveal that the crust beneath the <1.9 Ma magmatic segments has been heavily intruded; magmatic segments accommodate strain via both magma intrusion and faulting. We undertake field and remote sensing analyses of faults and eruptive centres in the magmatic segments to estimate the relative proportion of strain accommodated by faulting and magma intrusion and the kinematics of Quaternary faults. Up to half the ?10 km-long normal faults within the Boset-Kone and Fantale-Dofen magmatic segments have eruptive centres or extrusive lavas along their length. Comparison of the deformation field of the largest Quaternary fault and an elastic half-space dislocation model indicates a down-dip length of 10 km, coincident with the seismogenic layer thickness and the top of the seismically imaged mafic intrusions. These relations suggest that Quaternary faults are primarily driven by magma intrusion into the mid- to upper crust, which triggers faulting and dyke intrusion into the brittle upper crust. The active volcanoes of Boset, Fantale and Dofen all have elliptical shapes with their long axes in the direction N105, consistent with extension direction derived from earthquake focal mechanisms. Calderas show natural strains ranging from around 0.30 for Boset, 0.55 for Fantale, and 0.94 for Dofen. These values give extension strain rates of the order of 0.3 microstrain per year, comparable to geodetic models. Structural analyses reveal no evidence for transcurrent faults linking right-stepping magmatic segments. Instead, the tips of magmatic segments overlap, thereby accommodating strain transfer. The intimate relationship between faulting and magmatism in the northern MER is strikingly similar to that of slow-spreading mid-ocean ridges, but without the hard linkage zones of transform faults
Figure 11 in Parasenegalia and Pseudosenegalia (Fabaceae): New Genera of the Mimosoideae
No full textFigure 11. Pseudosenegalia riograndensis (Atahuachi & L. Rico) Seigler & Ebinger. —A. Twig with inflorescences and leaves. —B. Fruit. —C. Leaflet, adaxial surface. —D. Flower. —E. Petiolar gland. A–E from Antezana 1325 (NY).Published as part of Seigler, David S., Ebinger, John E., Riggins, Chance W., Terra, Vanessa & Miller, Joseph T., 2017, Parasenegalia and Pseudosenegalia (Fabaceae): New Genera of the Mimosoideae, pp. 180-205 in Novon 25 on page 202, DOI: 10.3417/2015050, http://zenodo.org/record/256146
Parasenegalia visco Seigler & Ebinger & Riggins & Terra & Miller 2017, comb. nov.
No full text6. Parasenegalia visco (Lorentz ex Griseb.) Seigler & Ebinger, comb. nov. Basionym: Acacia visco Lorentz ex Griseb., Abh. Königl. Ges. Wiss. Göttingen. 19: 135, 279. 1874. [Pl. Lorentz. 87. 18 74.] Senegalia visco (Lorentz ex Griseb.) Seigler & Ebinger in Seigler et al., Phytologia 88(1): 78. 2006. TYPE: Argentina. Catamarca: Fuerte de Andalgala ad rivulos, 13 Jan. 1872, P. G. Lorentz 34 0 (lectotype, designated here, GOET [image!] [11463]; isolectotypes, CORD [image!] [barcode] CORD00004860, SI [image!] [bc] SI001494). Figure 8. Acacia concinna Phil., Anales Univ. Chile 2: 170. 1870, nom. illeg., non Acacia concinna (Willd.) DC., Prodr. [A. P. de Candolle] 2: 464. 1825. TYPE: Argentina. Mendoza: in hortis, Philippi s.n. (lectotype, designated here, SGO [image seen] [barcode] SGO000002427, SGO photo at SI; isolectotypes, SGO fragm. at SI, SI photo at F! [27897], G, MO). Acacia platensis Manganaro, Anales Soc. Ci. Argent. 87: 128– 133, figs. 12, 13. 1919. Manganaroa platensis (Manganaro) Speg., Bol. Acad. Nac. Ci. 26: 254, pls. 255, 257, 265.1921. TYPE:Argentina (lectotype,designated by Cialdella, 1984: 96, LP [barcode] LPS24314). Acacia polyphylla Clos in Gay, Fl. Chil. 2: 254. 1846, nom. illeg., non Acacia polyphylla DC., Cat. Pl. Horti Monsp., 74. 18 13. Lysiloma polyphyllum Benth., Trans. Linn. Soc. London 30: 535. 1875. TYPE: Chile. ‘‘Pcia. Coquimbo, San Isidro, 1836, an culta’’ (lectotype, designated here, SGO [image seen]; isolectotypes, BR! [barcode] BR0000005117031, K [image seen] [bc] K000530853, P [image seen] [bc] P02142747. P [image seen] [bc] P03641821, P [image seen] [bc] P0 3 6 4 1 8 2 2, P [image seen] [bc] P03641823, P [image seen] [bc] P03641824, SGO fragm. at SI [image seen] [bc] SI661495). Acacia riparia Kunth b [var.] angustifoliola Kuntze, Revis. Gen. Pl. 3(3): 47. 1898. TYPE: Bolivia. Santa Cruz: Sierra de Santa Cruz, 2000 m, C. E. O. Kuntze s.n. (lectotype, designated here, NY! [barcode] NY00001542; isolectotype, F!). Manganaroa subsericea Speg., Bol. Acad. Nac. Ci. 26: 267. 1921 [1923]. TYPE: Argentina. Salta: ‘‘In dumetis montanis praeandinis, locis Quebrada de Guachipas et Pampa grande vocatis,’’ C. L. Spegazzini s.n. (lectotype, designated by Seigler et al., 2006a: 78, LP (LPS-14305) [image seen] [barcode] LP001053; isolectotype, LP [bc] LP001054). Tree to 25 m tall; bark not seen; twigs light to dark reddish brown, not flexuous, terete, glabrous to lightly puberulent; short shoots absent; prickles absent. Leaves alternate, 60–170 mm long; stipules light to dark brown, linear, symmetrical, flattened, straight, herbaceous, 2–6 mm long, 0.4–0.7 mm wide near the base, usually glabrous, tardily deciduous; petiole adaxially grooved, 25–45 mm long, lightly puberulent; petiolar gland solitary, anywhere along the petiole, sessile, usually oblong, 0.7–2.7 mm long, apex flattened to depressed, glabrous; rachis adaxially grooved, 35–130 mm long, puberulent, an oval to orbicular gland 0.5–1.2 mm across between the uppermost 1 to 2 pinna pairs, apex flattened to depressed, glabrous; pinnae (3)4 to 11(14) pairs/leaf, 40–70 mm long, 8–21 mm between pinna pairs; paraphyllidia 0.5–1.2 mm long; petiolule 1.1–2.2 mm long; leaflets 25 to 50 pairs/pinna, opposite, 0.8–2.1 mm between leaflet pairs, oblong, 3–7 X 0.8–2.1 mm, appressed pubescent on both surfaces, lateral veins sometimes obvious, 1 to 3 veins from the base, base oblique, truncate on one side, margins lightly ciliate, apex narrowly acute to acuminate, midvein submarginal, bluish purple beneath. Inflorescence a densely 40- to 75-flowered globose head 16–23 mm across, 1 to 3 in the leaf axils; peduncles 15–40 X 0.5–0.8 mm, puberulent; receptacle enlarged, not elongate, globose; involucre a small bract scattered along the peduncle, early deciduous, sometimes absent; floral bracts spatulate, 1.2–1.9 mm long, puberulent, early deciduous. Flowers sessile, white; calyx 5-lobed, 1.7–2.8 mm long, puberulent; corolla 5-lobed, 3.2– 4.3 mm long, lightly puberulent, lobes 1/5 the length of the corolla; stamens 60 to 90; stamen filaments 8– 11 mm long, distinct; anther glands present; ovary glabrous to rarely pubescent, stipe to 1 mm long. Legumes straight, flattened, not constricted between the seeds, oblong, 80–150 X 18–30 mm, chartaceous, transversely striate, glabrous to lightly puberulent, minute purple glands commonly present, dehiscent along both sutures; stipe 4–10 mm long; apex obtuse, the beak to 10 mm long; seeds uniseriate, no pulp, light brown, oval to oblong, strongly flattened, 9–13 X 7–10 mm, smooth; pleurogram U-shaped, 1.2–2.2 mm across. Habitat and distribution. Parasenegalia visco has been collected from seasonally wet mountains, deciduous forests, riparian forests, yungas, disturbed second-growth forests, and thickets, from 750 to 3000 m in northern Argentina, through Bolivia, northern Chile, and Peru. The taxon is commonly cultivated in Peru as well as where native (Rico Arce, 2007). Phenology. Parasenegalia visco flowers from October through January. Local names and uses. Local names include visco, arca, viscote, viscote negro, viscote blanco, and visite (Rico Arce, 2007). Parasenegalia visco is commonly cultivated for its wood. IUCN Red List category. Parasenegalia visco is assessed as Data Deficient (DD) at this time (IUCN, 2 0 0 1) but is an abundant species of southern South America and is commonly cultivat- ed in Argentina, Chile, Peru, Uruguay, and South Africa as an ornamental and as a fast-growing tree for cabinet wood (Rico Arce, 2 0 0 7). Parasenegalia visco is also known from numerous collections from Argentina and Bolivia and is probably of Least Concern (LC). Discussion. Parasenegalia visco is a large South American tree that is commonly cultivated and economically important for wood products. The globose inflorescence more than 16 mm across, along with the small leaflets (3–7 X 0.8–2.1 mm) with bluish purple midveins, distinguish this species from other members of the genus. Paul G. Lorentz was a German botanist and professor at the University of Córdoba, Argentina, until 1 8 74. His vascular plant collections at GOET were the sources for species described by Grisebach in his Plantae Lorentzianae (1 8 7 4) and Symbolae ad Floram Argentinam (1 8 7 9). The collection Lorentz 3 4 0 at GOET has an original label identifying the species as Acacia visite, which corresponded to the first name used by Grisebach in Plantae Lorentzianae (1 87 4: 1 3 5), which was emended in this same work to Acacia visco (1 87 4: 2 7 9). Although no collection was specified in the protologue, Lorentz can be assumed to be the collector (Stafleu & Cowan, 1 9 7 6: 1 0 1 1, 1 98 1: 1 5 7) for species similarly described by Grisebach. The lectotype at GOET (1 1 4 63) bears an original label with the spelling as Acacia Visite. This species was cited as introduced into South Africa as Acacia visite Griseb. (Ross, 1 9 7 5). Two common names were mentioned in the protologue by Grisebach (1874) for his Acacia species number 269 (1874: 135), as ‘‘[n]omen vernac. Visite, Visco.’’ These vernacular names were a source of confusion for the species epithet. On page 135, Grisebach described the new species as ‘‘269. Acacia Visite Gr.,’’ but this was emended by him in the same work on page 279 under ‘‘Verbesserungen’’ (Improvements), as ‘‘S. 135 nr. 269 statt [instead of] A. Visite Gr. lies [read] A. Visco Lor. in litt.’’ It is this emendation that indicated Grisebach’s intent to change the epithet to the other vernacular name, acknowledging Lorentz as well. Grisebach’s intent was further supported in his later treatment of Acacia in Symbolae ad Floram Argentinam (1879: 122), where the species was also cited as ‘‘ A. Visco Lor. mscr. – Syn. A. Visite Pl. Lor. [269],’’ with the number corresponding to the species number in the previous 1874 treatment in his Plantae Lorentzianae. The specimen chosen as the lectotype of Acacia concinna is representative of that species and is from the home institution (SGO) of Philippi, the describing author. No specimen was cited by Manganaro (1919: 128– 129) in the protologue for Acacia platensis, although she did note the species as ‘‘visto cultivada esta planta en Buenos Aires y en La Plata....’’ Spegazzini (1921) transferred the name to the genus Manganar- oa Speg. based on Manganaro’s study. Cialdella cited the specimen with the word ‘‘typus’’ written on it, presumably used by both previous investigators, LP [barcode] LPS24314, as the holotype. We interpret this as a de facto lectotypification. Although the name Mimosa polyphylla Clos was written on the type specimen of Acacia polyphylla Clos in Gay, apparently this name in Mimosa was never published. If this name were published, it would be the oldest name for Parasenegalia visco, but still illegitimate. The SGO lectotype chosen for A. polyphylla is representative of the species and is from the home institution of the describing author. Kuntze (1898: 47) described Acacia riparia var. angustifoliola from two countries as ‘‘Bolivia: Sierra de Santa Cruz 2000 m. and Argentina: Provinz Santiago.’’ Of these two possible syntypes, the NY (barcode NY0 0 0 0 1 5 4 2) sheet from Bolivia was annotated by Seigler and Ebinger (2009) as the holotype, emended here as the lectotype. A syntype of Manganaroa subsericea from Argentina (prov. Buenos Aires, La Plata, Jardín Botanico ‘‘Facultad de Agron.’’), also identified as the collection C. L. Spegazzini s.n., is at LP (LPS- 14305) (Cialdella, 1984). Specimens examined. ARGENTINA. Catamarca: Andalgala, 1 9 5 0 m, 2 8 Nov. 19 4 6, C. A. O’Donnell 4 1 8 3 (S); S of Cumbre de las Lajos, 1 7 0 0 m, 2 6 Nov. 1 9 4 6, B. Sparre 9 7 6 (S); Choya–El Tofo, 1 8 0 0 m, 2 8 Nov. 1 9 4 6, B. Sparre 1 0 0 3 (S); Andalgala, 2 8 Nov. 1 9 46, E. Wall s.n. (MO). Córdoba: 4 km N of Sarmiento, 1 0 8 0 m, 1 2 Oct. 1 9 8 8, J. Aronson 7 6 4 6 (MO); Puesto del Paraiso, 4 Jan. 1 8 9 7, T. Stuckert 1 2 7 1 (G); Villa Rosario, 1 4 Nov. 1 9 0 2, T. Stuckert 1 1 9 6 3 (G). Jujuy: El Volcan, 1 3 May 1 8 7 3, Lorentz & Hieronymus 7 1 4 (S), 7 5 9 (S); Purmamarca, 1 1 Jan. 1 9 7 1, A. Krapovickas & C. L. Cristóbal 1 7 6 3 7 (WIS); 2 km de Volcan camino a Lozano, 2 3 4 0 m, 1 0 Feb. 1 9 9 8, O. Morrone, N. B. Deginani, A. M. Cialdella & L. M. Giussani 2 4 0 1 (MO); Sierra de Calidegus, 8 0 0 m, 1 5 Oct. 1 9 2 7, S. Venturi 5 3 8 2 (CAS, GH, MO); San Pedro, 7 5 0 m, 2 0 Oct. 1 9 2 9, S. Venturi 9 7 4 4 (CAS, MO); Purmamarca, 2 8 Oct. 1 9 8 2, E. M. Zardini & M. L. Pochettino 1 5 6 4 (MO). La Rioja: 1 0 km S of Famatina, RN 4 0, 1 4 5 0 m, 1 4 Mar. 1 9 9 3, S. M. Botta & D. C. Miconi 5 9 0 (MO); Famatina, 1 6 0 0 m, 1 1 Jan. 1 9 4 7, J. H. Hunziker 1 8 1 5 (MO); Castro Barros, 1 5 km W of Anillaco, 1 9 8 0 m, 3 0 Mar. 1 9 9 2, J. H. Hunziker & J. C. Gamerro 1 2 48 0 (MO); Los Duraznillas, 7 5 0 m, 3 Nov. 1 9 4 7, I. Huasi 3 5 (GH). Salta: 2 0 km S of Salta, 1 1 2 0 m, 5 Nov. 1 9 8 8, J. Aronson 7 6 9 0 (MO); Cafayate, 8 Nov. 1 9 7 8, A. L. Cabrera, S. Botto, C. Ezcurra, A. M. Ragonese & M. Vazques A. 2 9 7 0 3 (MO); Cafayate, 8 Jan. 1 9 7 2, A. Krapovickas & C. L. Cristóbal 2 0 7 2 7 (WIS); Chorrillos, 2 1 1 0 m, 1 7 Jan. 1 9 41, T. Meyer 3 5 6 0 (GH); San Fernando, 6 May 1 9 4 7, T. Meyer 1 2 4 5 7 (RSA, US); Iruya, 2 7 0 0–2 8 0 0 m, 8 Nov. 1 9 8 8, L. J. Novara, T. Adzet & J. Masso 8 1 9 8 (B, M); Salta, 5 Nov. 1 9 8 2, E. M. Zardini 1 6 1 9 (MO); Iruya, 1 0 Feb. 1 9 8 3, E. M. Zardini 1 9 6 5 (GH); Iruya, 1 0 Feb. 1 9 8 3, E. M. Zardini, M. L. Pochettino, J. Hurrell, C. Iudica & D. Ramadori 1 9 6 5 (MO). Tucuman: San Javier, 1 0 50 m, 4 Nov. 1 9 7 8, S. A. Renvoize, M. Wilmot-Dear & R. Kiesling 3 3 6 4 (MO); Francas a Zarate, 7 8 0 m, 1 2 Oct. 1 9 2 5, Schreiter 6 8 5 9 0 (BM); Tapia, 2 7 Oct. 1 9 7 6, D. S. Seigler & F. Vervoorst 1 0 1 0 8A (EIU, ILL); Tapia, 2 7 Oct. 1 9 7 6, D. S. Seigler & F. Vervoorst 1 0 1 1 4 (ILL, MO); 1 3.8 km SE of Amaicha del Valle on rd. to Tafi del Valle, 2 4 0 0 m, 4 May 1 9 8 5, J. C. Solomon 1 3 5 3 6 (MO); Yerba Buena, 7 0 0 m, 1 9 2 6, S. Venturi 6 7 (GH); Tapia, 7 5 0 m, 2 4 Oct. 1 9 2 3, S. Venturi 2 4 7 6 (CAS, MO); Cerro del Campo, 8 0 0 m, 4 Nov. 1 9 2 8, S. Venturi 7 4 5 2 (GH). BOLIVIA. Chuquisaca: Comunidad Pitatorillas, 27 7 4 m, 2 2 Sep. 2 0 0 7, M. Jiménez, E. Cervantes & F. Janko 3 6 1 (ILL, MO). Cochabamba: camino hacia Omereque, Km. 1 8 6, 2 0 4 0 m, 2 7 Oct. 1 9 9 3, C. Antezana 3 9 7 (MO); vic. of Cochabamba, 1 8 9 1, M. Bang 9 2 1 (MO); city of Cochabamba, 1 8 Nov. 1 9 8 2, L. Bohs 1 9 9 0 (F, GH); near Arani, 2 7 7 0 m, May 1 9 4 7, M. Cardenas & H. C. Cutler 3 8 8 3 (GH); Arani, 2 7 0 0 m, 2 9 Nov. 1 9 7 9, T. Feuerer 6 9 4 2 (HBG); park, Colina de San Sebastian, Cochabamba, 2 57 5 m, 2 4 Nov. 1 9 8 4, M. Nee 3 0 3 5 2 (MO); 6 km NE of El Convento, 2 5 4 6 m, 1 3 Mar. 2 0 0 3, L. Rico 1 5 5 9 (MO); Mizque, 2 0 2 5 m, 2 7 Dec. 2 0 0 2, L. Rico & T. Windsor-Shaw 1 1 9 9 (MO); Carrasco, 2 1 0 0 m, 1 1 Feb. 1 9 8 7, J. C. Solomon & M. Nee 1 6 0 2 4 (ILL, MO, NY). La Paz: Hacienda Huajchilla, 1 8 km SE of La Paz, 3 0 0 0 m, 1 8 Dec. 1 9 8 6, J. C. Solomon 1 5 7 7 7 (ILL, MO). Potosí: Charcas, 2 5 0 0 m, A. Uzedo 5 (HBG). Santa Cruz: Saipina, 18 0 0 m, 2 2 Oct. 1 9 94, J. Balcazar 6 9 (MO); hills E of Salta, 1 3 0 0–1 4 0 0 m, 2 2 Sep. 1 9 8 5, A. Gentry & C. Palacia 5 1 7 3 1A (MO); rd. from Mairana to Postrervalle, 7.7 km SSE of Quirusillas, 1 75 0 m, 3 1 Dec. 1 9 9 7, M. Nee 4 7 6 6 0 (ILL, MO); 3.7 km NW of bridge over Rio Comarapa at Comarapa, 2 0 0 0 m, 2 4 Nov. 1 9 9 9, M. Nee 5 0 5 9 3 (MO); 5 km SW of Comarapa on rd. to Chilón, 1 7 7 5 m, 2 6 Nov. 1 9 9 9, M. Nee 5 0 6 6 8 (MO); 4 0 km E of Comarapa, 1 7 4 0 m, 2 2 Oct. 1 9 9 1, M. Saldias & T. Pennington 1 4 7 9 (MO); 1 1 km de Comarapa, 2 7 4 0 m, 3 July 1 9 8 9, D. N. Smith, V. García & M. Buddensiek 1 3 6 0 7 (MO); Comarapa, 2 0 0 0 m, 2 6 Oct. 1 9 2 8, J. Steinbach 8 5 7 8 (A, GH, S); Huasacañada, 2 0 5 0 m, 1 5 Feb. 1 9 9 0, I. G. Vargas C. 4 2 9 (MO); Huasacanãda, 2 0 5 0 m, 5 Nov. 1 9 8 9, I. G. Vargas C. 3 3 3 (MO); Huasacañada, 5 km S of Vallegrande, 2 0 5 0 m, 3 Nov. 1 9 9 0, I. G. Vargas C. 8 0 4 (MO); Huasacañada, 5 km S of Vallegrande, 2 0 5 0 m, 1 5 May 1 9 9 2, I. G. Vargas C. 1 3 9 8 (MO); Vallegrande, 1 3 km pasando Pucara en el camino hacia el Puente del Río Grande, 1 1 5 0 m, 2 1 Oct. 2 0 0 1, I. G. Vargas, C. Jordan & A. Vargas J. 6 6 2 2 (ILL, MO). Tarija: 6 km SW of Chocloca, 2 0 0 0 m, 2 5 Mar. 1 9 7 9, St. G. Beck 7 5 1 (US); Tarija, 1 9 2 0 m, 1 0 Jan. 1 9 7 9, C. Ruiz s.n. (US); 3 0 km de Tarija (vers Entre Rios), 1 8 5 0 m, 3 Dec. 1 9 7 5, J. R. de Sloover 3 8 1 (MO). CHILE. Tarapaca: Arica Prov., 1st Region, Codpa, 1 8 2 0 m, 1 2 Feb. 1 9 8 9, J. Aronson 7 7 5 8 (MO). PERU. Lima: Lima, 2 8 Nov. 1 9 6 6, S. S. Tillett 6 6 1 1-5 7 (A) (cultivated). Tacna: Alrededores de Tacna, 3 0 Oct. 1 9 4 8, R. Ferreyra 4 0 7 1 (MO, US).Published as part of Seigler, David S., Ebinger, John E., Riggins, Chance W., Terra, Vanessa & Miller, Joseph T., 2017, Parasenegalia and Pseudosenegalia (Fabaceae): New Genera of the Mimosoideae, pp. 180-205 in Novon 25 on pages 194-196, DOI: 10.3417/2015050, http://zenodo.org/record/256146
FIGURE 1. Senegalia hoehnei. A in A new species of Senegalia (Fabaceae) from Brazil
No full textFIGURE 1. Senegalia hoehnei. A: Leaf and petiolar glands; B: leaflet upper surface; C: inflorescence; D: flower. A from Fonseca 16 (US), B, C, D Mexia 4494 (US); drawn by Alexa Musgrove.Published as part of Seigler, David S., Morim, Marli Pires, Barros, Michel & Ebinger, John E., 2013, A new species of Senegalia (Fabaceae) from Brazil, pp. 59-63 in Phytotaxa 132 (1) on page 60, DOI: 10.11646/phytotaxa.132.1.6, http://zenodo.org/record/508606
The nature of the crust beneath the Afar triple junction: Evidence from receiver functions
No full textThe Afar depression is an ideal locale to study the role of extension and magmatism as rifting progresses to seafloor spreading. Here we present receiver function results from new and legacy experiments. Crustal thickness ranges from ?45 km beneath the highlands to ?16 km beneath an incipient oceanic spreading center in northern Afar. The crust beneath Afar has a thickness of 20–26 km outside the currently active rift segments and thins northward. It is bounded by thick crust beneath the highlands of the western plateau (?40 km) and southeastern plateau (?35 km). The western plateau shows VP/VS ranging between 1.7–1.9, suggesting a mafic altered crust, likely associated with Cenozoic flood basalts, or current magmatism. The southeastern plateau shows VP/VS more typical of silicic continental crust (?1.78). For crustal thicknesses <26 km, high VP/VS (>2.0) can only be explained by significant amounts of magmatic intrusions in the lower crust. This suggests that melt emplacement plays an important role in late stage rifting, and melt in the lower crust likely feeds magmatic activity. The crust between the location of the Miocene Red Sea rift axis and the current rift axis is thinner (<22 km) with higher VP/VS (>2.0) than beneath the eastern part of Afar (>26 km, VP/VS < 1.9). This suggests that the eastern region contains less partial melt, has undergone less stretching/extension and has preserved a more continental crustal signature than west of the current rift axis. The Red Sea rift axis appears to have migrated eastward through time to accommodate the migration of the Afar triple junction
Comparison of dike intrusions in an incipient seafloor-spreading segment in Afar, Ethiopia: Seismicity perspectives
No full textOceanic crust is accreted through the emplacement of dikes at spreading ridges, but the role of dike intrusion in plate boundary deformation during continental rupture remains poorly understood. Between 2005 and 2009 the ?70 km long Dabbahu?Manda Hararo rift segment in Ethiopia has experienced 14 large volume dike intrusions, 9 of which were recorded on temporary seismic arrays. A detailed comparison of the seismic characteristics of the seismically monitored dikes is presented with implications for dike intrusion processes and magmatic plumbing systems. All of the migrating swarms of earthquakes started from a <5 km radius zone at the middle of the Dabbahu?Manda Hararo segment, and traveled northward and southward along the rift axis. Small magnitude earthquakes associated with the margins of the propagating dike tips are followed by the largest magnitude, primarily low?frequency earthquakes. The seismic moment distributions show >80% of energy is released during the propagation phase, with minimal seismic energy release after the dike propagation ceases. We interpret that faulting and graben formation above the dikes occurs hours after the passage of the dike tip, coincident with the onset of low?frequency earthquakes. Dike lengths show no systematic reduction in length with time, suggesting that topographic loading and stress barriers influence dike length, as well as changes in tectonic stress. The propagation velocities of all the dikes follow a decaying exponential. Northward propagating dikes had faster average velocities than those that propagated southward, suggesting preconditioning by the 2005 megadike, or ongoing heating from a subcrustal magma source north of the midsegment
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