Monticalia speciosa J. Calvo & Romol., 2019

Calvo, Joel & Romoleroux, Katya, 2019, Monticalia speciosa (Senecioneae, Compositae), a noteworthy new species from Ecuador, Phytotaxa 400 (4), pp. 246-250 : 247

Monticalia speciosa J. Calvo & Romol. , sp. nov. ( Fig. 1 , 2 )

Type: — ECUADOR. Napo: Papallacta , sendero “Agua y Vida”, lagunas de Anteojos, 0º18’42’’S 78º09’54’’W, 3935 m, páramo de pajonal, 18 Oct 2018, K. Romoleroux & J. Calvo 6168 (holotype: QCA 241524 ; isotype: MO) .

It differs from the other radiate species of Monticalia by its minute leaves, which are sessile to subsessile, elliptic, ciliate on the margins and midrib, and concolorous, and by having eight involucral bracts.

Shrub 2–3.5 m tall; stem to 15 cm in diam. at the base; young stems slightly corrugated, covered by multicellular trichomes 0.9–1.9 mm. Leaves alternate, with short internodes 0.8–1.5 mm, sessile to subsessile; lamina elliptic, 3.1–4.1 mm long, 1.2–1.9 mm wide, rather obtuse at the apex with a callous-like acumen, plane, somewhat fleshy, ciliate on the margins and midrib (cilia ca. 0.4 mm long), concolorous, light green, outspreading, somewhat reflexed with age, with a gibbous-base ca. 0.3 mm long at attachment point with the stem. Synflorescence corymbiform or subumbelliform, with bracts similar to the upper cauline leaves that decrease in size upwards and become linear-oblong. Capitula heterogamous, radiate, with pedicels covered by multicellular trichomes; involucre obconical, 8–8.5 mm long, 5–6 mm wide at the apex. Involucral bracts 8, linear-oblong, 7.2–7.3 mm long, 0.9–1.5 mm wide, smooth or 1-keeled, glabrescent, usually with the apex dark-purplish. Supplementary bracts 4–6, linear-subulate, 3.4–5.4 mm long, 0.7–0.9 mm wide, smooth, a half to two-thirds as long as the involucral bracts, with scattered trichomes on the margins and the apex usually dark-purplish. Ray florets 8, female, 9.5–10 mm long, 1.5–1.6 mm wide (limb 6.5–6.9 mm long, 4-nerved, 3-toothed at the apex), yellow. Disc florets 9–14, 7.1–7.7 mm long, 0.9–1 mm wide, 5-lobed, yellow. Anthers ca. 2.2 mm long, auriculate to very shortly caudate (ca. 1/6 as long as the filament collar); filament collar balusterform. Style-branches truncate with a crown of sweeping hairs. Achenes (immature) glabrous; pappus 6.5–7.6 mm long, barbellate, whitish. Chromosome number: unknown.

Distribution and habitat: — Ecuador (Napo). This species is known from the highlands of Papallacta, in the southwestern part of the Cayambe-Coca National Park. Monticalia speciosa thrives in humid grassy páramos and around the transition between high montane forest and páramo, at elevations of 3750–4050 m. Some species that were observed in the same habitat are Baccharis padifolia , Diplostephium hartwegii , Gynoxys spp. , Monticalia andicola , M. arbutifolia , M. befarioides , and M. peruviana .

Phenology: —Collected in bloom in October.

Etymology: —The epithet speciosa means showy, splendid, which refers to the outstanding habit of this plant when it blooms.

Discussion: —The new species can be easily identified by its minute leaves, which are sessile to subsessile, elliptic, ciliate on the margins and midrib, and plainly concolorous. The leaves of M. speciosa are gibbous-based, character that has not been observed in other species. It is also characterized by its radiate capitula with eight involucral bracts.

The distribution of M. speciosa overlaps with M.andicola ( Turczaninow1851: 91) Jeffrey (1992: 69) , M. arbutifolia (Kunth in Humboldt et al. 1818: 143) Jeffrey (1992: 70), M. befarioides ( Cuatrecasas 1953: 134) Nordenstam (1996: 49) , and M. peruviana ( Persoon 1807: 436) Jeffrey (1992: 72) . Among these, it only might be confused with the latter species; however, several characters are useful to discriminate them from each other ( Fig. 2 ). Monticalia peruviana is a smaller shrub with discolorous leaves due to the whitish lanate indumentum beneath. The margins are revolute and not ciliate as in M. speciosa . The color of the leaves is also very different in the living plants (dark green in P. peruviana vs. light green in M. speciosa ). The involucre of M. peruviana has 12–13 involucral bracts and ray florets whereas M. speciosa has only eight. In Ecuador there is another species with minute leaves, i.e., M. empetroides ( Cuatrecasas 1954: 41) Jeffrey (1992: 70) . Any confusion is unlikely because this latter species has strongly revolute leaves, which are whitish lanate beneath. The number of involucral bracts is also different (12 vs. 8 in M. speciosa ). In Colombia no radiate species with eight involucral bracts are known.

It is important to note that any collection belonging to the new species was found among the Monticalia material (and related genera) kept at the Ecuadorian herbaria HA, LOJA, Q, QAP, QCA, QCNE, and QPLS. Taking in account that M. speciosa is a large shrub reaching up to 3.5 m tall and displaying showy yellow capitula, it is odd how this species has been overlooked until now.

Figures

FIGURE 1. Monticalia speciosa. A. Habitat. B. Stems in bloom. C. Detail of the capitula. D. Detail of the leaves. Photographs by J. Calvo at the locus classicus.

FIGURE 2. Monticalia speciosa (plant details on the left) compared to M. peruviana (plant details on the right). A. Ray florets. B. Involucres. C. Leaves. D. Synflorescences. Photographs by J. Calvo at the locus classicus.