Paepalanthus dendroides (Kunth in H.B.K.) Kunth

Hensold, Nancy, 2016, The Andean Paepalanthus pilosus complex (Eriocaulaceae): a revision with three new taxa, PhytoKeys 64, pp. 1-57 : 20-25

2. Paepalanthus dendroides (Kunth in H.B.K.) Kunth Figs 2A , 3C-E , 7

Paepalanthus dendroides (Kunth in H.B.K.) Kunth, Enum. Pl. 3: 507. 1841.

Eriocaulon dendroides Kunth in H.B.K., Nov. Gen. Sp. (quarto ed.) 1: 251, t. 59, fig. 2. 1815 [1816]. Type: Colombia. Cundinamarca: "Crescit in frigidis montanae planitiei Bogotensis inter Suba et Suacha, alt. 1340 hex.," Jul 1801, Bonpland & Humboldt s.n. (lectotype, here designated: B [B 10 0243900]; syntypes: B [B-W 2366], HAL [HAL 0109752], P [P01762723]).

Paepalanthus barkleyi Moldenke, Phytologia 3: 114. 1949. Syn. nov. Type: Colombia. Antioquia: 1 km N of Santa Rosa de Osos, 2600 m, 25 Sep 1948, S. Posada S., M. Torregrosa & F. Barkley 18A100 (holotype: NY; isotypes: COL [COL000006903], CORD [CORD00002162], LIL [LIL000143], US [US00088317]).

Paepalanthus karstenii var. corei Moldenke, Phytologia 29: 386. 1975. Syn. nov. Type: Colombia. Cauca: Above Purace, 11,000 ft, 19 Feb 1944, E. L. Core 272a (holotype: NY; isotypes: W n.v., WVA n.v.)

Paepalanthus karstenii f. corei (Moldenke) Moldenke. Phytologia 45: 296. 1980. Syn. nov. Type: Based on Paepalanthus karstenii var. corei Moldenke.

Type.

Based on Eriocaulon dendroides Kunth in H.B.K.

Description.

Plants terrestrial or partly submerged, forming densely leafy cushions or mats reported up to 30 cm in diameter (Fassett 25929), the erect branchlets ca. 1-5 cm. Leaves linear-subulate, 9-22 mm long × 0.85-1.6 mm wide, tip cuspidate-acute, persistently pilose to hirsutulous adaxially with white roughened hairs, sometimes nearly glabrous (Peru, Cajamarca and Pasco), mostly eciliate, consistently paler green than Paepalanthus caryonauta or Paepalanthus pilosus , with veins slightly salient below. Peduncles 20-130 mm long, pale, rigidulous (Peru) or often soft and compressible and then noticeably constricted at apex when dry, glabrous except for an apical collar of sericeous appressed hairs; peduncle sheaths 13-23 mm long, tightly enclosing the peduncle, equaling or scarcely exsert from leaf mat, tufted at apex otherwise mostly glabrous. Capitula 3.5-5 mm wide. Involucral bracts about equaling flowers, ovate, similar to Paepalanthus caryonauta but the outer bracts more hyaline, paler, sometimes uniformly gold and glabrous except at margins. Trichomes of bract and sepal apices obtuse to clavate, strongly tuberculate. Flowers ca. 12-17 per capitulum, pistillate peripheral, the staminate equaling to subequaling the pistillate in number. Pistillate flowers: Pedicels ca. 0.25-0.45 mm long, fine, not thickened at maturity. Sepals obovate-spatulate, 1.15-1.85 mm long × 0.65-0.85 mm wide, 0.15-0.25 mm wide at base, blackish-brown, short-ciliate along upper margin and bearded with longer appressed hairs on upper dorsum, the basal half of the midrib hygroscopically thickened, and spadiceous-brown in fruit, the broad distal half of the sepal remaining chartaceous, suberect, detaching from diaspore upon dispersal. Petals broadly spatulate, 1.15-1.75 mm long, 0.55-1.0 mm wide, ca. 1.6-2.3 times longer than wide, cream-colored and densely long-pilose with tuberculate trichomes on the abaxial surface flanking the midvein, not thickening, dispersed with fruit. Gynoecium with style base 0.15-0.25 mm long, the nectaries 0.55-0.7 (-0.85) mm long, the glandular portion colorless to pale pink to red- or yellow-brown, penicillate, slightly curved after anthesis, the apical ring of papillae colorless (white), thin- to thick-walled; styles 0.75-0.9 mm, mostly thinner and less pigmented than in Paepalanthus pilosus or Paepalanthus caryonauta . Seeds 0.6-0.75 mm long, orange-brown, the pseudotrichomes weak, erect upon wetting but collapsing soon after (few seeds observed). Staminate flowers: Pedicels (0.35-) 0.4-0.6 mm long, fine, membranous, nearly glabrous. Sepals 1.1-1.9 mm long × 0.35-0.5 mm wide, narrowed to base and very shallowly fused or if fused up to half the sepal length, not thickening, the calyx base not obconic at maturity, color and pubescence as in pistillate flowers. Corolla (1.0-) 1.4-1.7 (-1.95) mm long; the anthophore alone (0.35-) 0.55-0.95 mm long, comprising ca. 40-60% of the corolla length, membranous and ca. 0.1-0.2 mm in diameter at base, 0.3 mm at apex, the lobed tube (0.55-) 0.65-0.9 (-1.0) mm long. Filaments often unpigmented, slightly less exsert than in Paepalanthus caryonauta , the base of the anther rarely exsert more than 0.3 mm beyond lobe tips. Nectaries well-included within tube, usually only half-equaling the sinuses.

Phenology.

In Central America, flowering from March to April, in the dry season, and from August to September, the wet season, punctuated by a short dry period or veranillo ( Grayum et al. 2004). In Antioquia, Colombia, collected mostly in rainy season from April to September. Elsewhere in Colombia, from July to February. In Peru, collected in anthesis from January to May (Cuzco, Pasco; wet season), and in August (Cajamarca, Huanuco; dry season); in post-anthesis from March to November.

Distribution.

Costa Rica (Cerro de Talamanca): Limón, Puntarenas. Panama: Bocas del Toro. Colombia (Central and Eastern Cordilleras): Antioquia, Bogotá D.C., Boyacá, Cauca, Cundinamarca, Nariño, Santander, Norte de Santander. Peru: Cajamarca, Cuzco, Huánuco, Pasco, Puno. Brazil (Pico da Neblina): Amazonas. (Fig. 8 ).

Habitat and ecology.

A terrestrial or partly submerged aquatic, in open marshy subparamo, low paramo or cloud forest margins, in bogs, wet meadows, seeps, commonly associated with Sphagnum or tussock grasses, sometimes shrubs or Blechnum . Elevation mostly 2300-3200 m, but as low as 1900 m in Antioquia, and up to 3800 m in Cuzco (Abra Acjanaco), Peru. In the high elevation Cuzco plants seed production does not appear abundant, abortive flowers are common, and smut fungus infection is observed.

Conservation status.

The conservation status of this widespread species is presumed to be of Least Concern ( IUCN 2014). However it may have recently disappeared from the disturbed paramos near Bogotá, where it hasn’t been collected since 1917. Its lower elevation of occurrence and semi-aquatic habit may make it more vulnerable than its relatives to habitat loss due to disturbance.

Taxonomic history.

Paepalanthus dendroides was initially described by Kunth and later Körnicke (1863) as having unbranched stems with leaves clustered toward the apex and peduncles “umbellate” or in terminal fascicles, a misinterpretation likely due to the small size of the specimens. In addition, Kunth described both Paepalanthus pilosus and Paepalanthus dendroides as having bifid stigmas; his sketch of the gynoecium of Paepalanthus dendroides is mounted on the lectotype sheet. The published plate shows only 3 bifid stigmas, while the sketch shows three presumed filiform “appendages,” alternating with three thick shallowly bifid “stigmas.” Körnicke (1863) later corrected the description of Paepalanthus pilosus to "stigmas simple" but accepted without comment the bifid stigmas of Paepalanthus dendroides . I have only seen a scan of the type, which clearly corresponds to Paepalanthus dendroides as here treated, and can only assume Kunth either misinterpreted the gynoecial structure as he had done for Paepalanthus pilosus , or examined an abnormal flower. There are no species in this alliance or among any Andean Paepalanthus of similar habit, which have normally bifid stigmas.

Paepalanthus dendroides was placed in synonymy of Paepalanthus pilosus by Ruhland (1903), but the specialist Harold Moldenke (fl. 1930's-1980's) generally distinguished the two species in his annotation work, misapplying the name Paepalanthus pilosus to Paepalanthus dendroides and to lax long-pedunculate specimens of Paepalanthus pilosus , while using the name Paepalanthus karstenii for most material of Paepalanthus pilosus . (See detailed discussion under Paepalanthus pilosus .) The name Paepalanthus dendroides was removed from synonymy and its identity clarified by Hensold and Hammel (2003), but is still commonly used for long-pedunculate plants of Paepalanthus pilosus (cf. Madriñán and Zapata 2001).

Misapplied name.

Paepalanthus pilosus sensu Ruhland (1903) in part, Moldenke (1953, 1975c, 1979, 1983) in part, Brako and Hensold (1993) in part, Huft (1994), Santa Cruz (2011), non (Kunth in H.B.K.) Kunth.

Discussion.

Paepalanthus dendroides is a variable species across its range, but may be distinguished from its close relatives by the character syndrome in Table 1 . The broadly spatulate and densely pilose petals which enfold the diaspore, together with reduced pigmentation of the gynoecia, filaments and seeds, are characteristic. The subaquatic habit and the lower elevation range are distinctive as well. It tends to have a less congested habit and softer leaves than its relatives, but also may form compact, stiff- leaved cushions with dwarf peduncles on some sites, as in the type of Paepalanthus karstenii var. corei , and then floral characters may be important for identification. It should be noted that key characters useful for Costa Rican material ( Hensold and Hammel 2003) do not consistently apply in South America, including the pale-striped sepal midlines, the constricted peduncle apex, and the dorsally glabrous involucral bracts. These characters are variable in Colombia and rare in Peru.

Of the Peruvian collections, those from Huánuco, Cuzco, and Puno share a similar morphology, with leaves relatively narrow and conspicuously pilose above, the outer involucral bracts dusky gray, and the nectaries somewhat pigmented. Leaf pubescence easily distinguishes these populations from sympatric Paepalanthus caryonauta . In comparison, specimens from Cajamarca and Pasco have broader, glabrous leaves. The Cajamarca collections were examined only from photos, but the plants closely match Colombian material of Paepalanthus dendroides and are from a similar habitat and elevation. The Pasco collection (Vasquez 29038) has floral characters somewhat intermediate with Paepalanthus pilosus or Paepalanthus caryonauta , as follows: petals 2.0-2.3(-3.0) times longer than wide; style base 0.4-0.5 mm; nectaries darker, 0.85-0.95 mm long; styles to 1.0 mm long; nectaries of male flowers almost reaching the mouth of the corolla.

Evidence of hybridization.

The Pasco, Peru, specimen ( Vásquez 29038) was collected very near a plant fully intermediate between it and Paepalanthus caryonauta , with abortive locules and stigmas (Monteagudo 7938; full specimen citation under Paepalanthus caryonauta ). Typical Paepalanthus caryonauta (Monteagudo et al. 16143) is recorded 20 km to the east.

In Colombia, introgression between Paepalanthus dendroides and Paepalanthus pilosus is suspected in the disturbed paramos east of Bogotá. Although Paepalanthus dendroides was originally described from near Bogotá, I have only seen one other typical individual from this vicinity (Pennell 1997), collected at Quebrada Chapinero in 1917, the same locality where the type of Paepalanthus schultesii (= Paepalanthus pilosus ) was collected in 1941. Paepalanthus pilosus is presently abundant near Bogotá, but seems particularly variable and with an unusual tendency to long peduncles, lax habit, and variably shaped bracts, suggesting intermediacy with Paepalanthus dendroides (see Paepalanthus pilosus discussion). Typical Paepalanthus dendroides is currently found north of Bogotá, where it is mostly recorded from elevations 500-900 m lower than nearby collections of Paepalanthus pilosus . In Panamá, however, typical Paepalanthus dendroides and Paepalanthus pilosus are sympatric at the Cerro Fabrega massif, without apparent intermediates.

Selected specimens examined

(of 56 total). COSTA RICA. Limón: Cerro Kamuk , 9°14'30"-15'30"N, 83°03'30"-04'30"W, 2900-3100 m, 23-26 Mar 1984, Davidse et al. 25928 (F, MO) ; Atlantic slope, between Rio Terbi and Rio Sini , 9°00'- 9°12'N, 82°58'- 82°59'W, 2400-2750 m, 13 Sep 1984, Davidse et al. 28991 (F, MO) . Limón / Puntarenas: Cerro Kasir , 9°12'N, 83°03'30"W, 2950 m, 22 Mar 1984, Davidse & Herrera 29339 (F, MO) . PANAMA. Bocas del Toro: [ Fabrega Massif ], S of Cerro Itamut, 9°05'40"N, 82°53'06"W, 3200 m, 17 Mar 2006, Monro & Knapp 5369 (MO) . COLOMBIA. Antioquia: Mpio. Belmira , Finca El Paramo, 3000-3130 m, 29 Jan 1995, Fonnegra et al. 5408 (F) ; N of Las Ventanas , 07 02'N, 75 30'W, 1730-1920 m, 26 May 1984, Luteyn et al. 10737 (F) ; Yarumal, Llanos de Cuiva , 06°50'N, 75°30'W, 2700 m, 27 Jul 1986, Roldán 252 (MO) ; Bello, Vereda San Felix , 06°21'N, 75°39'W, 3050 m, 7 May 1988, Zarucchi & Echeverri 6332 (MO) ; Bogotá, D.C.: Chapinero , 2700-2800 m, 18-23 Sep 1917, Pennell 1997 (F) ; Boyacá: Belen, Huina , 7 May 1959, Barclay 7629 (MO) ; 14 km NW of Arcabuco, 2440 m, 20 Aug 1944, Fassett 25629 (MO), Mpio. Chiscas, sector Duartes Arriba , 2850 m, 8 Jul 2003, Galindo-T. et al. 1303 (COL [COL000057819]) ; Cauca: Valencia , 3090 m, 24 Sep 1958, H. G. Barclay 5730 (MO) ; Cordillera Central, E slope [probably valley of Rio San José, Moscoso ], 2980-3000 m, 2 Feb 1947, Cuatrecasas 23654 (F) ; Paramo de Paletara , 3000 m, 18 Nov 1968, Espinal & Ramos 3310 (MO) ; Cundinamarca: Pantanos de Fuquene , 2600 m, Mar 1930, Pérez-Arbeláez 66 (COL [COL 000223800]) ; Nariño: Putumayo, Paramo de Santa Lucia , 2900-3100 m, 9 Jan 1941, Cuatrecasas 11866 (F) ; Santander: N of Cerrito , 3200 m, 12 Oct 1944, Fassett 25929 (MO) ; Las Vegas , 2600-3000 m, 21- 23 Dec 1926, Killip & Smith 16064 (F) ; 11 km NE of Berlin , 3330 m, 18 Jul 1979, Stuessy & Funk 5612 (MICH) ; Santander / Norte de Santander: Paramo de la Laguna, between Pamplona and Bucaramanga , 2900 m, 26 Feb 1939, A. H. G. Alston 7333 (F) . BRAZIL. Amazonas: Pico da Neblina , 2700 m, 21 Aug 1985, C. Farney & Pessoal do 1° B.F.E. 901 (RB) PERU. Cajamarca: Prov. Santa Cruz, Distr. de Pulan , El Progreso, 2700 m, 5 Aug 2006, L. Santa Cruz 653 (USM [photo]) . Cuzco: Prov. Paucartambo, Parque Nac. del Manú, Acjanaco , 3400-3500 m, 3 May 1990, Cano 3361 (F), 2 Mar 1991, Cano 4437 (F), 3500-3600 m, 21 Jul 1990, León 2243 (F) ; Trocha Acjanaco - Macho Cruz , 3350 m, 2 Mar 1991, León & Huapaya 2683 (F, USM[photo]) ; Paso de Tres Cruces, Cerro de Cusilluyoc , 3800-3900 m, 9 May 1925, Pennell 13866 (F) ; Prov. La Convención, Distr. Santa Ana, Pavayoc , 2600 m, 14 Mar 1953, Woytkowski 567 (USM [photo]) . Huánuco: [probably "Saxiapata, in the montana of Pillao and Chacahuasi, " Aug-Sept 1787], Ruiz & Pavón s.n. (MO 1612102); Villcabamba, Hacienda on Rio Chinchao , 6,000 ft, 17-26 July 1923, Macbride 5182 (F) . Pasco: Prov. Oxapampa, Dist. Huancabamba, Santa Barbara , 10°20'35"S, 75°39'00"W, 3400-3500 m, 25 Jan 2004, Vásquez et al. 29038 (F, MO, USM) . Puno: [Prov. Carabaya, San Gaban], "in summis Cordiller. jugis pr. San Govan," Jul 1854, Lechler in Pl. peruv., ed. Hohenacker 2206 (P [P01762726]) .

Figures

Figure 2. Capitula and leaf tips of Paepalanthus pilosus and relatives A-E Fruiting capitula with diaspores; sepals detaching (A, D) or intact (C, E) A Paepalanthus dendroides B-C Paepalanthus caryonauta D Paepalanthus pilosus var. pilosus E Paepalanthus lodiculoides F-J Paepalanthus pilosus var. pilosus, involucral bract variation. Arrows = tips of the torn peduncle sheath. (A Davidse 28991 B Barclay 5176, Ecuador C Dudley 11060, Peru D Cuatrecasas 25574 E Ollgaard 9717 F Cuatrecasas 25882 G Cuatrecasas 5553 H Ollgaard 9557 I Cano 16840 J Jorgensen 2366.)

Figure 3. Vascular bundle morphology, adaxial side up. A Paepalanthus caryonauta B Paepalanthus pilosus var. pilosus C-E Paepalanthus dendroides F Paepalanthus huancabambensis midvein, with bundle sheath extensions. (A Valenzuela 8117 B Barbour 3427 C Leon 2683 D-E Leon 2243. F: Sagastegui 16799 D-F Mesophyll darkened for contrast.)

Figure 7. Paepalanthus dendroides. A-C Habit (A Nunez 7773 B Cuatrecasas 23654 C Davidse 28991) D-F Pistillate flower in fruit (Pennell 13866) D Whole flower E Diaspore with two sepals removed F Seeds G Gynoecium of young fruit (Luteyn 10737).

Figure 8. Distribution of Paepalanthus dendroides, Paepalanthus huancabambensis, and Paepalanthus lodiculoides.