1. Family: Boraginaceae Juss.
    1. Genus: Heliotropium Tourn. ex L.
      1. Heliotropium megalanthum I.M.Johnst.

        This species is accepted, and its native range is Chile (Atacama, Coquimbo).

    [KBu]

    Luebert, F. 2013. A revision of Heliotropium sect. Cochranea (Heliotropiaceae). Kew Bulletin 68: 1. DOI https://doi.org/10.1007/s12225-013-9432-6

    Type
    Type: Chile, in prov. Coquimbo [dry valleys and hills between Huasco and Copiapó], [Sept. 1841], T. Bridges 1341 (lectotype BM [photo GH], selected by Johnston (1928b: 35); isolectotypes E not seen [digital photograph], K [photo SGO 2266]). Replacement name for Cochranea corymbosa.
    Habit
    Decumbent shrubs, 0.09 – 0.4 m tall, with ascending branches, densely foliose to the base of the inflorescence
    Stem
    Stems and foliage glabrous or sparsely strigose
    Leaves
    Leaves alternate, somewhat succulent, solitary or grouped in fascicles of up to 12 leaves, sessile, oblanceolate to ovate-spathulate, 13 – 44 (− 50) × 3.5 – 10.5 (− 12) mm; lamina glabrous with hirsute (pustulate) pubescence only on the margin, dark-green, margin entire, revolute, base attenuate in a pseudopetiole, apex obtuse, with only the main vein conspicuous
    Inflorescences
    Inflorescences terminal, elongate, dichotomously branched, to c. 15 cm long
    Flowers
    Flowers sessile or shortly pedicellate, alternate, erect
    Calyx
    Calyx cylindrical, green; calyx lobes linear, glutinous, fused only at the base, hirsute only on the margin outside, strigose within, (2 –) 2.5 – 6.5 × 0.5 – 1 mm, free portion 3 – 6 mm long, apex acute
    Corolla
    Corolla infundibuliform, sparsely strigose to glabrous outside, dull white with yellow or orange-yellow throat; limb horizontally spreading, 7.5 – 12.5 mm wide, lobes rounded; tube longer than the calyx, 6.5 – 11 mm long
    Stamens
    Stamens included or exserted at late anthesis; filaments adnate to petals; anthers linear-lanceolate, glabrous, base cordate, apex acute, c. 1 mm long, overlapping the stigmatic head
    Ovary
    Ovary glabrous, subglobose, c. 0.5 mm diam., with a basal nectar ring
    Style
    Style glabrous, c. 1 – 1.5 mm long, equal to or slightly longer than the stigmatic head
    Stigma
    Stigmatic head conic, elongated, bilobate, c. 1 × 0.7 mm
    Fruits
    Fruits dry, ellipsoid, rugose, glabrous, pale brown to yellowish, c. 1.5 × 2 mm diam., falling apart at maturity into two 2-seeded nutlets, each c. 1.5 × 1.5 mm diam.
    Pollen
    Mesocolpi concave in the polar view Colpiferous sides convex Endoapertures 3 – 3.5 μm diam., contracted at the centre Pollen prolate, 28 – 32.5 × 19.5 – 24 μm Amb almost 3-lobate Exine thickness c. 1 μm uniform in the whole of its extent (from Ricardi 2300 in Marticorena 1968)
    Distribution
    Littoral and interior areas of the provinces of Copiapó and Huasco (Región de Atacama, Chile), between 27°42'S and 28°38'S (Map 9). The supposed locality for Kummerow s.n. (Fray Jorge, Prov. Limarí) is probably wrong.
    Ecology
    Coastal and interior sand plains and rocky outcrops of the south-central Atacama Desert, 0 – 620 m. It forms part of the scrub vegetation dominated by Atriplex clivicola (Amaranthaceae), Eulychnia breviflora (Cactaceae), Oxalis virgosa (Oxalidaceae), among others. Heliotropium megalanthum loses almost all its above-ground structures (i.e., flowers and leaves) in dry years, when it is not possible to recognise it.
    Conservation
    Vulnerable (VU), criterion B2 (a,b,c). The reduced projected area of occupancy of this species is associated with an extremely fragmented distribution of populations, a predicted decline in its area of occupancy (Luebert 2010), in a zone subject to interannual climatic fluctuations that directly affect the number of mature individuals.
    Phenology

    September to October, with a flowering peak in September (Vidiella et al. 1999).

    Vernacular
    Heliotropio amarillo (Spanish; Riedemann 2004, erroneously cited as Heliotropium linariifolium).
    Note

    This species is characterised by its large flowers with a yellow to orange corolla throat and its decumbent habit. The other two decumbent species in section Cochranea (Heliotropium linariifolium and H. eremogenum) have strigose lamina (vs glabrous lamina with pustulate pubescence only on the margin in H. megalanthum), definitely orange corollas (H. linariifolium) or smaller flowers (H. eremogenum), and both are distributed north of the geographic range of H. megalanthum, with which they do not overlap. In its area of distribution, H. megalanthum might be confounded with H. floridum, but the latter has strigose lamina and erect habit and the style longer than the stigmatic head.

    The epithet megalanthum refers to the large flowers this species possesses.

    [KBu]
    Use
    According to Riedemann (2004) and Riedemann et al. (2006) this species has potential as an ornamental. Johnston (1928b) considered it a beautiful plant, a characteristic probably derived from the size of its flowers and inflorescences and its yellow to orange, sometimes spreading, corolla limb.

    Distribution

    Native to:

    Chile Central, Chile North

    Heliotropium megalanthum I.M.Johnst. appears in other Kew resources:

    First published in Contr. Gray Herb. 81: 35 (1928)

    Accepted by

    • Zuloaga, F.O., Morrone, O. , Belgrano, M.J., Marticorena, C. & Marchesi, E. (eds.) (2008). Catálogo de las Plantas Vasculares del Cono Sur Monographs in Systematic Botany from the Missouri Botanical Garden 107: 1-3348. Missouri Botanical Garden.

    Literature

    Kew Bulletin
    • Förther (1998: 206)
    • Marticorena (1968: 44)
    • (Johnston 1928b: 35)
    Kew Backbone Distributions
    • Zuloaga, F.O., Morrone, O. , Belgrano, M.J., Marticorena, C. & Marchesi, E. (eds.) (2008). Catálogo de las Plantas Vasculares del Cono Sur Monographs in Systematic Botany from the Missouri Botanical Garden 107: 1-3348. Missouri Botanical Garden.

    Sources

    Kew Backbone Distributions
    The International Plant Names Index and World Checklist of Selected Plant Families 2019. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

    Kew Bulletin
    Kew Bulletin
    http://creativecommons.org/licenses/by-nc-sa/3.0

    Kew Names and Taxonomic Backbone
    The International Plant Names Index and World Checklist of Selected Plant Families 2019. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0