Heliotropium pamparomasense Luebert & Weigend, 2012

Luebert, Federico & Weigend, Maximilian, 2012, Three new species of Heliotropium sect. Heliothamnus (Boraginaceae) from Peru, Phytotaxa 49 (1), pp. 35-44 : 38-41

Heliotropium pamparomasense Luebert & Weigend , spec. nov. (Figs. 2A–B, E, H, 4.)

Type: ― PERU. Ancash: Prov. Huaylas, road from Moro to Pamparomas , [9º5'S, 77º59'W], 2000 m, 25 October 2000, M . Weigend , H . Förther & N . Dostert 2000/968 (holotype USM, isotypes BSB, HUT, MSB) .

Erect shrub, densely branched, 3–4 m tall with the young branches densely pubescent. Leaves alternate, solitary, petiolate, internodes 1–5 cm; petiole 0.5–2.0(–3.0) cm long; lamina elliptical, discolorous, 4–12(–15) × 1.5–5.0(–6.0) cm on flowering shoots, to 30 × 15 cm on vegetative shoots, base attenuate, apex acute, limb with the veins well-marked and cross-venulate on both sides, secondary veins acroscopical, pubescent, reddish-villous on the adaxial surface, lanate-tomentose on the abaxial surface, pubescence homogeneously distributed. Inflorescences terminal, dichotomically branched up to 4(–5) times, up to 17 cm long overall, with the axes villous and the terminal branches scorpioid. Flowers complete, sessile, 4–12 mm long. Calyx persistent, not or slightly accrescent, with the sepals divided to 2/3 of their length; calyx lobes lanceolate, hirsute outside, pilose inside, especially towards the apex, 3–5 mm long, 1.5–2.5 mm wide at the base, base usually broadened, apex acute, protracted. Corolla infundibuliform, white, mauve or pale pink, 4–12 mm long, 4–6 mm wide; lobes rounded, 0.5–1.5 × 0.5–2.0 mm; tube villous outside, glabrous inside. Stamens 3–4 mm long; filaments 1.5–2.0 mm long, arising from corolla tube with the distal portion free, free portion 0.5– 0.7 mm long. Anthers included, coherent, linear to sagittate, 1.2–2.2 × 0.5–0.6 mm, margins shortly papillose; base rounded, cordate, located above the apex of the stigmatic head; apex incurved, papillose. Ovary glabrous, 0.2–0.3 mm high, 0.7–0.8 mm wide; disc nectary well developed, 1.0– 1.2 mm wide. Style shorter than the stigmatic head, 0.1–0.2 mm long. Stigmatic head conical, with a basal receptive ring, 0.8–1.0 mm long, 0.8– 0.9 mm wide at the base, finely papillose. Fruits dry, dehiscent, falling into 4 one-seeded nutlets. Nutlets solid (without cavities), surface reticulate, stipitately glandular, dark brown, 1.5–1.7 × 1.2–1.3 mm. Pollen subprolate, ca. 19–24 × 16–21 µm, 3-colporate, 3-pseudocolpate, sexine psilate (Weigend & Skrabal 5890).

Distribution and habitat:—C ommon in the quebradas (streams) around Pamparomas (Dept. Ancash, Cordillera Negra) at elevations of ca. 2000–2800 m ( Fig. 3 ). It grows together with other tall shrubs of, e.g., Salvia, Iochroma, Cleome and Alnus acuminata Kunth in relatively moist situations along (seasonal) streams and at the base of rocks. On drier sites between the quebradas it is replaced by H. corymbosum Ruiz & Pavón (1799: 2) , which is extremely common in the area. Another set of collections is from Depts. Lambayeque and Cajamarca, but so far no material is known from the intervening area. This latter area is considerably moister and the species is here found all over the mountain sides in forest remnants and hedges.

Etymology:— The name refers to the town near from where the type collection comes.

Additional specimens examined (paratypes): ― PERU. Lambayeque: Prov . Lambayeque, km 4.6 road Olmos-Jaén , [5º59'S, 79º39'W], 1900–2000 m, 28 June 1959, R . Ferreyra 13770 ( MSB, USM) . Cajamarca: Prov. Santa Cruz, Bosque de Monteseco [6º52'S, 79º5'W], 19 December 1984, A . Sagástegui , E . García & S . Leiva 12371 ( HUT, MSB). Prov. San Miguel de Pallaques , Hacienda Lives, [7º5'S, 79º3'W], 2300 m, 27 July 1957, A . Díaz s.n. ( MSB); Lives, 7º4'55''S, 79º2'51''W, 1500 m, 13 October 2000, M . Weigend , E . Rodríguez , H . Förther & N . Dostert 2000/719 ( BSB, HUT, MSB). Prov. San Pablo, San Pablo, [7º7'S, 78º50'W], 1906, A . Weberbauer 3873 ( G). Prov. Contumazá, Vicinity of Trinidad , [7º21'S, 79º2'W] 1950 m, 6 July 1977, A . Sagástegui , E . Alvitez & J . Moscatero 8939 ( G, HUT); Way fom Guzmango to San Benito, 7º23'24''S, 78º54'1''W, 2562 m, 25 April 2001, T . Henning & C . Schneider 36 ( BSB, HUT, M, USM); Road from (Contumazá) Guzmango to Jeton, 3 km after Guzmango, 7º23'31''S, 78º54'4''W, 2179 m, 15 June 2008, T . Henning & J . Schulz 37 ( BSB); La Monatña (Guzmango-Contumazá), [6º25'S, 79º13'W], 2500 m, 18 May 1979, A . Sagástegui , E . Alvitez & J . Moscatero 9263 ( G); Along the road from Cascas to Contumazá, [7º26ºS, 78º47'W], 20 February 2002, N . Doster & R . Rodríguez 2002/01 ( BSB, HUT, M). Depto Ancash: Prov. Huaylas, at the road from Nepeña to Pamparomas , 2.9 km before Pamparomas , [9º5'S, 78º1'W], 2400–2600 m, 24 September 2001, M . Weigend & J . Skrabal 5890 ( BSB, MSB); from Pamparomas to Moro, S 09 ° 05,316'; W 077 ° 58,853', 2780 m, 14 October 2007, M . Weigend & H. H . Hilger 8911 ( USM) .

This species is allied to Heliotropium submolle Klotzsch (1852: 89) and H. rufipilum (Bentham 1845: 140) Johnston (1928: 44) . It differs from H. submolle by its glandular fruit and reddish pubescence (versus fruit glabrous and pubescence white in H. submolle ), and from H. rufipilum in its much more robust habit, coriaceous leaves with adaxially impressed veins, and not or only slightly accrescent calyx (versus membranaceous leaves without impressed veins and accrescent calyx in H. rufipilum ). Heliotropium pamparomasense is one of the tallest species of the entire genus and grows as a shrub easily 3–4 m tall, with thick, initially stiffly erect branches. The shrub produces very long, massive renewal shoots from the base, which have particularly huge leaves (> 30 cm long) and terminate in a compound inflorescence up to 40 cm in diameter compared to ca. 5–15 cm in other species.

The specimen Weberbauer 3873 from San Pablo was tentatively referred to H. submolle by Johnston (1928: 46). Leaf form, structure and pubescence of the material seen at G agree, however, with the rest of the material from the Depto. Cajamarca cited here, which are distinct from true H. submolle (Pavón s.n., B- WILLD!). Unfortunately the specimen Weberbauer 3873 has only young flowers, hence the glandular character of the fruit surface could not be verified.

The Contumazá and the Pamparomas populations are morphologically very similar in all aspects apart from flower colour: The Contumazá populations have cream-white flowers, the Pamparomas populations have pink to mauve flowers. In the absence of collections from the intervening area we nevertheless advocate treating them as a single species at the moment.

Figures

FIGURE 3. Distribution of the newly described species in Peru.