Presliophytum incanum (Graham) Weigend (2006: 467)

Acuña, Rafael & Weigend, Maximilian, 2017, A taxonomic revision of the western South American genus Presliophytum (Loasaceae), Phytotaxa 329 (1), pp. 51-68 : 61-63

3. Presliophytum incanum (Graham) Weigend (2006: 467) ( Figs. 1A, F, G , 3C, D, G)

≡ Loasa incana Graham (1830: 169)

Type: — PERU [Lima, Prov. Canta], Valley of Canta, Yazo [sic], 1830. Cruckshanks s.n. (holotype: E barcode E00085317 !; isotype: BM!, K barcode K000372846 !) .

= Loasa atriplicifolia Presl (1832: 61 , Tab. 39). Lectotype (designated in Weigend 1998: 168):—Tab. 39 ( Presl 1832).

= Loasa ruiziana Don (1834: 64) . ≡ Loasa incana Ruiz & Pavón (1959: 406 , Tab. 441, fig. a). Lectotype (designated in Weigend 1998: 168):—tab. 441, fig. a. ( Ruiz & Pavón 1959). Epitype (designated in Weigend 1998: 168):—[ PERU, Lima, Prov. Huarochirí] anno? “ Loasa sp. nova de Huayaquil” Pavón. s.n. (BM!). Possible type:— PERU [Lima, Prov. Canta], ex Obrajillo, 1778, H. Ruiz et al. s.n. (MA barcode MA813475 [photo!])

Coarse, densely branched perennial shrub 50–150 cm tall. Stem epidermis with abundant glochidiate and scabrid trichomes, scattered stinging and short-smooth trichomes. Taproot present, usually thickened and fleshy. Leaves lobate (lobes more profound in younger plants), less frequently deeply thoothed, opposite below, alternate above, petiole 7–35 mm, with glochidiate, scabrid and scattered stinging trichomes (rarely with short-smooth trichomes), lamina 40–100 × 25–80 mm, ovate with (0–)3–6 lobes on each side, margin crenate or toothed, base cuneate to shallowly cordate, sometimes asymmetric, blade and lobe apices acute, upperside with scabrid and stinging trichomes (the latter sparse and mostly on veins), rarely with short-smooth trichomes, in older leaves the trichome tips may fall, leaving behind basal cells forming scale-like structures, underside densely covered in glochidiate and scabrid trichomes (rarely with stinging trichomes on veins). Inflorescences densely frondose, complex asymmetrical dichasia, to ca. 100 cm long; each flower erect or horizontal in anthesis with two, petiolate or sessile, prophylls (flowers apparently solitary and irregularly alternating with foliage leaves) 15–45 × 2–25 mm, similar to leaves in morphology and indumentum, but sometimes subentire and very narrowly lanceolate (2–3 mm wide); pedicels with glochidiate, scabrid and scattered stinging trichomes. Sepals five, lanceolate, 5–12 × 3–6 mm green, 3-veined, margins entire, more than 1.5 × long as wide, indumentum of each surface similar to that of the respective leaf surface; petals five, half to full spreading, cymbiform, 11–20 mm long, white (when full spreading) to beige or yellow (when half spreading), sometimes slightly tinged greenish on the abaxial surface, with abundant glochidiate, short-smooth and scattered, weak stinging trichomes, margins entire, vertical to slightly involute, rarely with indistinct, narrow (1 mm wide) flat margins; nectar scales five, 4–5 mm long, white, beige or yellow (not contrasting with petal color), unicolored, concave, slightly bulging, with a poorly developed papillose-margined neck and rudimentary apical wings. Filiform dorsal threads, three, 5–7 mm long, of about the same length, attached subapically to the nectar scale. Staminodes 2 per scale, 10– 12 mm, distal 2/3rds filiform, glabrous, proximal third abruptly expanded, with a flange towards the nectar scale, margins papillose. Stamens 50–75, filaments 7–10 mm long. Style 7–10 mm, straight, but twisting after fertilization, ovary inferior, with a densely pubescent roof covered mostly in scabrid trichomes, sometimes with few short-smooth trichomes, outer wall with abundant glochidiate, scabrid and stinging trichomes, placentae 3–5. Fruit a capsule 5–10 mm diameter, subglobose or broadly conical, opening with 3–5 apical valves; seeds ca. 1200–2500 per capsule, 0.5 mm × 0.2–0.5 mm, testa dark brown, foveate-reticulate. Seed testa cells polygonal.

Notes:— Ruiz, Pavón and Dombey were in Obrajillo in 1778 ( Lang 1985). Therefore, it seems likely that H. Ruiz et al. s.n. (MA barcode MA813475) was collected at that time and possibly is a type of Loasa incana Ruiz & Pavón (not Loasa incana Graham ). This species shows considerable plasticity in leaf morphology. As greenhouse plants age, they produce progressively smaller leaves. The difference in size after two years is quite noticeable. Habitat also seems to account for considerable variation: plants growing in dry river beds and cliffs often have diminutive leaves while plants growing in dry forest edge or scrub have broader leaves. There is morphological variation related to geography ( Figs. 1F, G ), but this is greatly obscured by the changes resulting of age and habitat conditions. More consistent differences possibly related to geographic origin are evident in floral morphology as most of the the populations from Arequipa and Moquegua have yellow, half spreading corollas ( Fig. 3D) that are different from the white, full spreading corollas more common in plants further north ( Fig. 3C). The type material studied and cultivated by Graham (1830) had white, spreading corollas. It must be noticed, however, that some plants in Arequipa and Moquegua have been reported as having white flowers, at the same time yellow flowered individuals have been collected as far north as Lima ( Fig. 4 ). In preserved specimens, the color of the corolla turns yellowish, independently of the origin of the plants, and, in the absence of field notes, it is unclear whether white and yellow flowered populations overlap with each other, and how extensive is this overlap, if any. Plants with white flowers tend to have stems predominantly with scabrid trichomes while yellow flowered plants have stems mostly with glochidiate trichomes, but this difference appears to be minor and not always consistent. Preliminary genetic evidence coming from plastid markers suggests that the yellow-flowered populations from the south could be more closely related to P. arequipense than to the northern white-flowered populations. But more robust evidence is needed before making a taxonomic decision.

Etymology:— The epithet refers to the hoary appearance of the plants due to their abundant scabrid and glochidiate trichomes.

Illustrations:— Habit and morphology: Presl (1832: Tab. XXXIX), Urban & Gilg (1900: Tab. VII. Fig. 1 –10), Ruiz & Pavón (1959: Icon. CDXLI.a). Leaf: Weigend (1997: Fig. 21.8). Inflorescence architecture: Urban (1892a: Taf. XII.6), Weigend (1997: Fig. 29.2), Weigend et al. (2004b: Fig. 6C). Floral diagram: Urban (1892b: Taf. XIV.21), Gilg (1894: Fig. 37N), Grau (1997, Ab. 3). Sepal morphology: Weigend (1997: Fig. 40.2). Petal ontogeny: Weigend (1997: Fig. 43.13–14). Nectar scale ontogeny: Weigend (1997: Fig. 53.2, mislabeled as “ Loasa grandis ”). Fruit: Weigend (1997: Fig. 56.20).

Distribution:— Endemic to Peru. Known from Departmento de Piura to Departmento de Moquegua, from sea level to over 3000 m elevation. This species is very widely distributed on the Pacific slope of Peru, but is largely replaced by P. heucheraefolium in coastal Departamento de Áncash ( Fig. 4 ).

Phenology:— This species is known to flower all year round.

Ecology:— This is one of the most widespread taxa of Loasoideae , with a very broad ecological tolerance in dry habitats. Like other species of the genus, it grows on cliffs, in dry washes, on road banks and scree slopes at low to intermediate elevations, sometimes associated with cacti and other dry scrub plants. It can also be found in Andean scrub, coastal lomas and disturbed habitats.

Conservation status:— This species fares well in human disturbed habitats and is one of the most abundant species of Loasaceae in Peru. Due to its abundance and resilience to human disturbance it is considered a LC species ( Rodríguez & Weigend 2006).

Additional specimens examined:— PERU. Dept. Unknown: San Mateo in the Quebrada , s.a., coll. Unknown 696 ( K: K000372847 ) ; s.a., Martinet s.n. ( P: P04589533 ) ; s.a., Martinet 191 ( P: P04589534 ) ; San Bartolomé , July 1874, Martinet 168 ( P: P04589536 , P04589537 ) ; s.a., Neé s.n. ( F: n.842915) ; Piura: Prov. Unknown, Pariñas Valley, 35 miles east of Cape Pariñas , 4 September 1927, Haught 186 ( F) ; Prov. Talara, Pariñas valley , 20 miles inland, s.a., Haught F-111 ( F) ; Cajamarca: Prov. Santa Cruz, 35 Km from Santa Cruz on road to Catache , 1 Km after Catache , 4 May 2003, Weigend et al. 7546 ( BONN) ; Prov. San Miguel, Entre Quindén y Platanal (carretera hacia el Pueblo de Unión Agua Blanca ), 800 m, 6 October 2001, Rodríguez et al. 2423 ( F) ; Prov. Contumazá, Alrededores de Tembladera , 900 m, 23 May 1976, Sagástegui et al. 8529 ( F) ; Road from Pacasmayo to Cajamarca , ca. 20 Km from Pacasmayo on rocky roadside, 500 m, 1998, Dostert 98/165 ( F) ; Road from Chilete to Pacasmayo , 900 m, 1997, Weigend et al. 97/457 ( F) ; Ca. 30 Km from Chilete on road to Contumazá , 9 May 2003, Weigend et al. 7585 ( BONN) ; Al N. de Contumazá sobre el camino que conduce a Chilete, y que se desvía de la carretera Contumazá–Chilete, bajando Hoyada Verde , 1600 m, 3 July 1983, Sánchez et al. 3195 ( F) ; Chilete-Contumazá road, about midway between the villages ; 11 April 2003; Hufford et al. 4018 ( F) ; Alrededores de San Benito , 1300 m, 3 February 1985, Sagástegui et al. 12461 ( BONN, F) ; El Portachuelo ( Ascope - El Algarrobal), 780 m, 20 April 1984, Sagástegui 11387 ( BONN) ; La Libertad: Prov. Gran Chimú, Cascas –Contumazá road, 1.1 Km north of square in Cascas , 1350 m, 10 April 2003, Hufford et al. 4013 ( F) ; Prov. Ascope–Prov. Trujillo, Cerro Cabezón , 800 m, 3 July 1985, Mostacero et al. 767 ( F) ; ditto, 250 m, 4 November 1983, Sagástegui & López 10988 ( F) ; ditto, 500 m, 8 May 1999, Sagástegui et al. 16142 ( BONN, F) ; Prov. Otuzco, Ruta Simbal – La Cuesta, 1280 m, 2 September 1973, López & Sagástegui 8008 ( F) ; Prov. Trujillo, Pedregal , 800 m, 1 May 1994, Sagástegui 15289 ( F) ; Pedregal a Shirán , 300 m, 4 February 1974, Lourteig & López 2994 ( P) ; Road Trujillo–Otuzco near Shiran , 600 m, 1997, Weigend et al. 97/198 ( F) ; Alrededores de Shirán , 550 m, 10 June 1993, Leiva 772 ( F) ; Trujillo–Otuzco road, 31.5 Km east of the PanAmerican Highway in Trujillo and 6.2 Km west of Puente Shirán , 900 m, 15 April 2003, Hufford et al. 4025 ( F) ; Prov. Virú, Lomas de Virú. Cerro de las Lomas , 350 m, 12 October 2000, Weigend et al. 2000/695 ( BONN, F) ; Áncash: Prov. Corongo, Road from Huallanca to Yanac , near Yanac , 2800 m, 7 March 2001, Weigend et al. 5013 ( BONN) ; Road Sihuas to Corongo / Mirador (on Río Santa ), 3065 m, 26 April 2004, Weigend & Schwarzer 8039 ( BONN, F) ; Prov. Huaylas, 133 Km from Santa on road to Caraz , 2 Km after Huallanca , 13 May 2003, Weigend et al. 7655 ( BONN, F) ; Road from Caraz to Huaylas , ca. 2 Km after the turnoff to Huaylas from the Carretera Central , 2614 m, 28 November 2014, Henning et al. 9719 ( BONN) ; Cordillera Negra, 20.5 Km from Caraz on road to Huaylas , 2278 m, 29 April 2004, Weigend & Schwarzer 8048 ( BONN, F) ; Surrounding of Pamparomas to Tuteycon , 1950 m, 25 November 2006, Ackermann & Albán 616 ( BONN) ; Serpentine outside fields Shauintioc and Tuteycon , 15 May 2003, Weigend et al. 7688 ( BONN) ; Road from Pamparomas to Moro , branch to Ullpan , 2120 m, 14 October 2007, Weigend & Hilger 8912 ( BONN) ; Prov. Santa, Road from Moro to Pamparomas ( Caraz ), Cordillera Negra , lower desertic regions, 1400 m, 1997, Weigend & Dostert 97/121 ( F) ; Road from Moro to Pamparomas , 10 October 2002, Weigend et al. 7367 ( BONN, F) ; Lima: Prov. Unknown , s.a., Dombey s.n. ( P: P04588969 ) ; Road to Puruchuco, s.a., McLean s.n. ( K: K000372845 ) ; Prov. Huaura, Ámbar-Huaura, Laderas de Cerros , 1200 m, 6 August 2003, coll. Unknown 3267 ( BONN) ; Prov. Canta, Ex Obrajillo, s.a., Ruiz et al. s.n. ( MA: MA813475 ) ; Canta por abajo, 2300 m, 2 April 1953, Petersen & Ginting 1194 ( L) ; Quives , open rocky slope, 1300 m, 9 June 1925, Pennell 14309 ( F) ; Prov. Lima, Canta Valley , 7 km NE of Trapiche. On sandy sides of dry wash ; 800 m; 4 August 1957, Hutchinson 1012 ( F) ; Road from Trapiche to Quilca at ± 6 Km from Trapiche . Dry stream bed in Tillandsia desert. Granite sand, no cacti, 750 m, 02 January 1971, Hawkes et al. 4103 ( L) ; Chosica , 800 m, June 1949, Soukup 3796 ( F) ; Prov. Huarochirí, Near Huínco, above Chosica , 1900 m, 3 September 2004, Richter s.n. ( BONN) ; Carretera Central, just west of Matucana , 2300 m, 1997, Weigend & Dostert 97/12 ( F) ; Matucana. Steep rocky canyon slope ; soil loose, 2500 m, 19 April 1922, Macbride & Featherstone 257 ( F) ; Prov, Yauyos: Road from Yauyos to Jauja , few Km after Magdalena , 2300 m, 7 October 2002, Weigend et al. 7233 ( BONN) ; Road from Huancayo to San Vicente de Cañete. 193 Km from Huancayo , 872 m, 22 September 2001, Weigend & Skrabal 5888 ( BONN, F) ; Ica: Prov. Unknown , s.a., Martinet 47 ( P) ; Prov. Pisco, 1 Km before Puente Huaytará ( Km 73 road Pisco-Ayacucho ), 1450 m, 29 September 1997, Weigend & Förther 97/585 ( F) ; Prov. Nazca, Sol de Oro , 840 m, 2 January 2007, Huamantupa 8432 ( BONN) ; Km 17 on Road Nazca–Puquio , 1140 m, 2 October 1997, Weigend & Förther 97/642 ( F) ; Arequipa: Prov. Caravelí, Quebrada Ático , 50 m, 14 February 1998, Cátedra Ecología, s.n. ( FLSP 1343 ) ( P: P04574610 ) ; Prov. Condesuyos, Road from Aplao ( Castilla ) to Chuquibamba, S of bridge over Río Arma , Quebrada Huario , ca. 24.5–26 Km from Chuquibamba , 1550 m, 24 July 2010, Weigend et al. 9374 ( BONN) ; Prov. Camaná, Km 934 Panamericana Sur between Camaná and Tambillo, 1500 m, 5 October 1997, Weigend & Förther 97/760 ( F) ; Moquegua: Prov. General Sánchez Cerro, Omate. Laderas de cerros y bordes de camino, 2400 m, 15 September 2004, coll. Unknown 3239 ( BONN) ; Anexo de ‘ Laje’–San Francisco , 2270 m, 8 April 2003, Cáceres et al. 3014 ( BONN) ; Road from Omate to San Francisco above Omate. Hillsides of Urimalle , 1840 m, 8 December 2006, Ackermann & Cáceres 674 ( BONN, F) ; From Moquegua to Omate , 2798 m, 14 April 2004, Weigend & Schwarzer 7869 ( BONN) ; Prov. Mariscal Nieto, Road Moquegua to Omate , 74 Km from Moquegua , 1 Km before puente over Río Tambo , 14 April 2004, Weigend & Schwarzer 7862 ( BONN, F) ; Off Moquegua–Torata road, just above Torata , 14 September 2001, Hufford & McMahon 3835 ( F) ; 20 Km E of Moquegua on road to Torata , 2100 m, 13 October 1997, Weigend & Förther 97/850 ( F) ; 14 Km E of Moquegua on road to Torata , 1855 m, 13 October 1997, Weigend & Förther 97/848 ( F) ; Km 1126 Panamericana Sur. 14 Km N of Moquegua turnoff, 1200 m, 14 October 1997, Weigend & Förther 97/855 ( F) ; Río seco o aluvión, 1200 m, 9 April 1959, Vargas 12640 ( BONN) ; Cerca a Moquegua . Cauce seco, 800 m, 27 October 1966, Vargas 17970 ( BONN) .

4. Presliophytum malesherbioides (Phil.) R.H. Acuña & Weigend in Acuña et al. (2017: 373) ( Figs. 1C , 3E, I, K) ≡ Loasa malesherbioides Philippi (1864:74) Type: —[ CHILE, Coquimbo, Prov. Elqui] Baños del Toro, 1860/61, [H.] Volckmann s.n. (SGO?, B [†, photo F Neg. No.10208!]). = Loasa longiseta Philippi (1865: 347) . Lectotype (designated in Acuña et al., 2017: 373):—[ CHILE, Atacama, Prov. Copiapó] Quebrada de Puquios, Des. Atacama, 1865, F. Geisse s.n. (SGO barcode SGO000003405 [photo!]; isolectotype: SGO barcode SGO000003404

[photo!]).

Figures

FIGURE 1. Vegetative morphology of Presliophytum.A. Habit andhabitat of shrubby Presliophytum incanum (Quinistaquillas, Moquegua, Peru, not vouchered). The three species of Peruvian Presliophytum have similar habits. B. Habit and habitat of subshrubby Presliophytum sessiliflorum (Quebrada La Chimba,Antofagasta, Chile, Luebert et al. 3405, BONN; photo courtesy of F. Luebert).C. Habit and habitat of herbaceous Presliophytum malesherbioides (Juntas del Toro, Coquimbo, Chile, not vouchered; photo courtesy of M. Eyzaguirre). Mature specimens of this species range from unbranched annuals to densely branched subperennial herbs as the one illustrated. D. Mature leaf of Presliophytum arequipense (cultivated, seeds collected near Mollendo, Arequipa, Peru, Ortiz et al. 121, BONN). E. Mature leaf of Presliophytum heucheraefolium, (cultivated, seeds collected near Río Cacchán, Áncash, Peru, Weigend et al. 7691C, BONN). F. Mature leaf of Presliophytum incanum (cultivated, seeds collected near Ullpan, Áncash, Peru, Weigend & Hilger 8912C, BONN). G. Mature leaf of Presliophytum incanum (cultivated, seeds collected near Omate, Moquegua, Peru, Ackermann & Cáceres 674, BONN). Scale bars 15 mm. Photos by R.Acuña and M. Weigend, unless otherwise credited.

FIGURE 4. Natural distribution of Presliophytum based on herbarium specimens. P. incanum W = Presliophytum incanum with white or indeterminate color corollas. P. incanum Y = Presliophytum incanum with yellow corollas.