Plazia conferta Ruiz & Pav.

Shrubs 1–2 m tall, the branches erect to ascending; stems lacking spines. Leaves simple, sessile, in whorls at branch tips; blades lanceolate to oblanceolate, glabrous to glandular, usually appressed, the margins entire. Capitulescences of solitary, terminal heads, sessile. Capitula heterogamous, radiate or more rarely homogamous, discoid; involucres cylindrical to campanulate; receptacles plane, glabrous; phyllaries 5–7-seriate, lanceolate; ray florets 5–25, the corollas ligulate-bilabiate, the outer lip 4-nerved, tridentate, the inner lip bifid; styles cylindric, glabrous, bifid, the branches short, inconspicuous; disc florets 7–40, the corollas tubular, actinomorphic, glabrous, the limb deeply 5-lobed, the lobes greater than 1/3 the length of the corolla, coiled; anthers linear, the terminal appendages lanceolate, fused into a column, truncate, the bases caudate; styles claviform, the branches short, rounded. Achenes glabrous or glandular-pubescent; pappus of scabrid bristles, isomorphic, yellowish. Chromosome number: unknown.

All species are confined to the Andean Cordillera and associated inter-Andean valleys (Fig. 1). Two species are confinded to Peru; both are rare and only known from a few collection localities. Another species is restricted to the Andes of central Chile. Plazia daphanoides Wedd. is the only wideranging species, being recorded from southern Peru and adjacent Argentina, Bolivia and Chile, usually in high-elevation, dry sites (Cabrera 1978, Ferreyra 1980, 1995).

The genus Plazia was described by Ruiz López and Pavón (1794) and they subsequently published its first species, Plazia conferta Ruiz & Pav. (1798). All efforts at locating material corresponding to their type collection from Peru have not been successful (Cabrera 1960).

Weddell (1855) provided an emended generic description for Plazia and he recognized three species: Plazia conferta Ruiz & Pav., Plazia cheiranthifolia (J. Remy) Wedd., and Plazia daphnoides Wedd. Reiche (1905) picked up the implied transfers by Hoffmann (1890–1894) and treated Plazia in Chile as having three species: Plazia cheiranthifolia, Plazia pinifolia (Phil.) O.Hoffm. [= Gypothamnium pinifolium Phil.], and Plazia virgata (Phil.) O.Hoffmann [=Aphyllocladus denticulatus (J.Rémy ex Gay) Cabrera]. Recent floristic treatments have accepted Plazia as distinct from Aphyllocladus and Gypothamnium (e.g., Cabrera 1978, Ferreyra 1995, Hind 2009, Marticorena and Quezada 1985, Zuloaga and Morrone 1999). The addition of the northern Peruvian species described here brings the total number of recognized species to four.

CHILE, Región IV, Coquimbo, C. Gay s.n. (holotype: P00703596!; isotype: P00703598!).

Shrubs to 1.5 m tall; stems very resinous. Leaves oblong, 28–30 mm long, 7.5–8 mm wide, sessile, apically acute, 3–5-nerved, entire, thickened, glabrous. Capitulescences of solitary terminal heads. Capitula solitary, sessile; involucres campanulate, 25–30 mm long, c. 25 mm wide; phyllaries 3–4-seriate; inner lanceolate, 25–28 mm long, c. 3 mm wide; florets numerous, isomorphic, the outer with corollas subligulate. c. 10, lobes strongly coilled, inner florets 20–25; all corollas lobes c. 7 mm long, c. 4 mm wide, the tube c. 13 mm long; pappus to 16 mm long. Achenes 6–7-ribbed, glabrous, linear oblong, c. 7.5 mm long, c. 1.2 mm wide.

While it was once considered extinct, this species was recently rediscovered in the Precordillera of Ovalle (Faúndez and Saldivia 2008) and the description provided here is largely derived from the specimens and data in that publication. Since this species appears to be restricted to an area of no more than 2 km², it would be designated as “critically endangered” (IUCN 2001).

Plazia cheiranthifolia is a rare shruby species apparently confined to the central Chilean region near Coquimbo. It has the longest leaves of any species of Plazia and large capitula with broadly campanulate involucres. Rémy described as his Aglaodendron chieranthifolium as homogamous, all with bilabiate corollas with lobes of varying lengths. From the photo in Faúndez and Saldivia (2008), it appears there are perhaps nine subligulate corollas.

Aglaeodendron cheiranthifolium J.Rémy was based upon a collection by Claudo Gay deposited in Paris (P00703596). The isotype, also in Paris (P00703598), contains a small piece of paper c. 1 cm square, with the number “176” afixed to the lower left hand corner. This number corresponds to the page number of the collection citation in Rémy (1849). It should not be considered as an accession number for Claudo Gay as has been published in internet sources.

CHILE. Region IV. Prov. Limarí. Bocatoma Central Los Molles, Río Molles, 2590 m, 18 Jan 2007, P. Saldivia et al. s.n. (SGO154422!).

PERU. Junín: Acobamba [near Tarma], H. Ruiz López & J.A. Pavón s.n. (holotype: MA, n.v.).

Shrubs, branched, branches glabrous. Leaves oblanceolate, 22–42 mm long, 5–6 mm wide, glabrous, sessile, acute-mucronate, margin entire. Capitula with involucres 18–22 mm high, 12–16 mm wide; phyllaries 6–7-seriate, glabrous, lanceolate, the inner 22–25 mm long, 3–3.5 mm wide, acute, the outer gradually smaller; ray florets 18–20, the corollas 26–28 mm long, the tube 10–11 mm long, glabrous, the outer lip 14–15 mm long, 5–6 mm wide, 4-nerved, tridentate, the inner lip bipartite; disc florets 40–42, the corollas 15–18 mm long, the tube glabrous, the lobes 9–10 mm long, 1–1.2 mm wide, coiled; anthers 6–7 mm long. Achenes [ray] 4–5 mm long, 1.5–1.6 mm wide, glabrous; pappus c. 12 mm long; [disc] 4.5–5 mm long, 1–1.2 mm wide; pappus c. 14 mm long.

Endemic to an inter-Andean valley in central Peru from near Tarma; c. 3000 m. Given that this species appears confined to a single locality and of a few individuals, it would be considered “critically endangered” (IUCN 2001).

Plazia conferta is a rare species, and type material has not been located. No new material had been collected since Ruiz López and Pavón’s original gathering until a second collection was made by Felix Woytkowski at the type locality nearly 180 years after its original description. Cabrera (1960) was unsuccessful in locating Ruiz López and Pavón’s type material in the major European herbaria, including Madrid. We made inquiries to the Real Jardín Botánico in Madrid, but no collection of Plazia has surfaced as yet. Ferreyra (1980) cited duplicates of Woytkowski 52 as occurring at MO and F, but after exhaustive searching, no duplicate collections were located, and subsequently the duplicates were not cited in Ferreyra’s Flora of Peru treatment (1995). Further, during this study, we were unsuccessful in our efforts to examine the Woytkowski collection at USM, and the description provided by Ferreyra (1995) was used to quantify the differences between that species and the new one described here.

There is an error in the citation of the generic description in Florae Peruvianae Chilensis Prodromus (1794), where page “104” is cited in Systema Vegetabilium Florae Peruvianae et Chilensis (1798) incorrectly, and the generic description is actually on page 92.

Shrubs to 2 m, resinous. Leaves sessile; blades oblanceolate to lanceolate, 10–18(–20) mm long, (2–)3–4 mm wide, apically acute, basally cuneate, glandular-pubescent, the margins ciliate. Capitula with cylindrical involucres (15–)18–20 mm high, 7–8(–14) mm wide; phyllaries 3–6-seriate, lanceolate, the inner 20–21 mm long, 2.4–3 mm wide, the outer smaller; ray florets (5–)7–8(–10), the corollas 20–21 mm long, the tube 11–11.5 mm long, the outer lip 9–9.5 mm long, 2–3 mm wide, tridentate, the inner lip bipartite, 6–7 mm long; disc florets (7–)10–11(–12), the corollas white, 13–14 mm long, the tube 10–11 mm long, the lobes 7–8 mm long; anthers 5–6 mm long. Achenes [ray] 4.5–5 mm long, 1.2–1.4 mm wide, glandular; pappus c. 13 mm long; [disc] 5–5.5 mm long, 1 mm wide, glandular; pappus c. 12.5 mm long.

In Plazia, Plazia daphnoides displays the widest distribution with collections from the Andean Cordillera of southern Peru, Bolivia, Chile, and Argentina (3000–4000 m). While locally it may come while locally may come under stress from habitat reduction, it would be considered as of “least concern” (IUCN 2001).

This species is distinctive with the narrowest capitula with the fewest ray and disc florets within the genus. Ferreyra (1995) lists the type specimen as collected by H. Weddell near the locality of Tacora, which is now in northern Chile.

Weddell (1855) failed to describe a nominative variety (p. 13); however, the manner in which he presented the material examined in his studies suggests that his first variety represented his nominative variety [α villosa, foliis utrinque villosis]. Examination of a large suite of collections has failed to find consistant morphological variation combined with any geographic pattern to support recognition of varieties in this taxon.

Robinson’s (1980) new genus and species, Harthamnus boliviensis, was discovered by him to be a synonym of Plazia daphnoides shortly after its publication.

ARGENTINA. Jujuy: Dept. Humahusca, Mina Aguilar, Espinosa del Diablo, 3800 m, 12 Jan 1968, A.L. Cabrera et al. 18985 (LP, n.v.; SI014474!). Dept. Tumbaya, El Angosto de San José del Chañi, 3550 m, 26 Feb 1972, A.L. Cabrera, J. Frangi, A.M. de Frangi, R. Kiesling & E.M. Zardini 22463 (LP, n.v.; P04318222!). Salta: Dept. Poma, Colres, 31 Jan 1944, A. L. Cabrera 8331 (LP, n.v.; F1549306!, P02405527!).

BOLIVIA. Cochabamba: Sivingani, 11, 000 ft, 24 Mar 1950, W.M.A. Brooke 6219 (F1547725!). Tarija: Cercado, Tarija, 3900 m, 20 Feb 1904, K. Fiebrig 3101 (F520491!).

CHILE. Region XV. Prov. Parinacota. Putre, 3500 m, 29 Dec 1995, L. Landrum & S. Landrum 8883 (ASU0061610!); Quebrada Murmuntani, 3800 m, 13 May 2008, M.A. Trivelli s.n. (SGO156326!); Cordillera de Chapiquiña, 3600 m, 7 Mar 1927, C. Troll 3235 (B!).

PERU. Ayacucho, 83 km W of Puquio, 76 km E of Nazca, 3430 m, 22 Jun 1978, A. Gentry, M. Dillon, P. Berry, & J. Aronson 23273 (F1918361!).

PERU. La Libertad: Prov. Huamachuco, Pallar – Huaguil, carretera a Tayabamba, 3000 m, 23 Jun 1974, A. López M. & A. Sagástegui A. 8123 (holotype: HUT12930!, isotypes: F1863606!, US3266111!).

Plaziae confertae affinis, a qua foliis minoribus, capitulis majoribus et radiis 15–20 differt.

Shrubs to 1 m, the branches erect; stems lacking spines. Leaves simple, sessile, in whorls at branch tips; blades oblanceolate, 10–25 mm long, 1–3 mm wide, uninerved, adaxial and abaxial surfaces glabrous; margins entire. Capitulescences of solitary, terminal heads, sessile. Capitula heterogamous, radiate; involucres broadly campanulate, c. 25 mm wide, 30 mm in diameter; receptacles plane, glabrous; phyllaries 4–5-seriate, the outer ovate, 8–12 mm long, 4–6 mm wide, apically acuminate, the inner oblong 20–25 mm long, 4–5 mm wide, apically acute, ciliolate; ray florets 15–20, the corollas ligulate-bilabiate, whitish, the tube 4–5 mm long, the outer lip 4-nerved, 8–12 mm long, tridentate, the inner lip bifid; styles cylindric, glabrous, bifid, the branches short, inconspicuous; disc florets whitish, c. 40, the corollas tubular, actinomorphic, glabrous, the limb deeply 5-lobed, the lobes 5–8 mm long, c. 1/2 the length of the corolla, coiled; anthers linear, the terminal appendages lanceolate, fused into a column, truncate, the bases caudate; styles claviform, the branches short, rounded. Achenes [ray and disc] glabrous, 5-ribbed, 4–5 mm long; pappus of scabrid bristles, c. 15 mm long, isomorphic, pale yellow.

Known only from the type locality in an inter-Andean valley at around 3000 m (7°47.22'S, 77°52.27'W). The entire area surrounding Huamachuco and the road east to Tayabamba has been intensely cultivated for many years and is now highly disturbed by human pressure with expanding cultivation. Only fragmented small pockets of original habitats remain, usually in steeper quebradas. This species has not been recollected for 40 years and should be considered “critically endangered” (IUCN 2001).

The duplicates of the type collection of this new species were originally distributed under the generic name Diplostephium Kunth (1818), a member of the tribe Astereae. The overall morphology of the material does superficially resemble some members of Diplostephium, however, the bilabiate corollas, truncate style branches, and anther tails are typical for the Mutisieae not the Astereae. The new species was uncovered after the Flora of Peru treatment (Ferreyra 1995) was published and set aside for investigation. Only recently was the material encountered during routine filing, having been misplaced for nearly two decades.

The type locality is approximately 450 km north of its nearest congener, Plazia conferta, from near Tarma. Although the region where the original collections were made has been visited by numerous botanists, to our knowledge this species has not been recollected since 1974 when it was encountered by Abundio Sagástegui Alva and Arnaldo López Miranda. Casual efforts to find the plant again have not met with success. Given that the plant is quite showy and distinctive, it should not go undetected for long if it is indeed extant.

This species honors Dr Harold Robinson, Senior Research Curator at the National Herbarium, Smithsonian Institution. He suggested with his annotation of the US sheet, designated as an isotype, that this taxon was perhaps a new species of Plazia, and not an unusual Diplostephium, as had been suggested on the original label.