Heliotropium pycnophyllum Phil.

First published in Fl. Atacam.: 38 (1860)
This species is accepted
The native range of this species is N. Chile. It is a subshrub or shrub and grows primarily in the desert or dry shrubland biome.

Descriptions

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, Región de Atacama, Prov. Chañaral, Cachinal de la Costa, Dec. 1853, R. A. Philippi s.n. (holotype SGO 54374 [photo F, GH, NY, US], isotype W 12981).
Morphology General Habit
Low and globose erect shrub, (0.2 –) 0.4 – 1.0 (− 1.5) m tall, profusely branched, with short branches, densely foliose to the apex
Morphology Stem
Stems and foliage densely covered by short, substrigose and incane pubescence, somewhat glutinous
Morphology Leaves
Leaves alternate, solitary or grouped in fascicles of up to 16 leaves, sessile, succulent, linear, oblong-linear or oblong-ovate, 3.5 – 12 (− 16) × 0.7 – 3 (− 4.5) mm, sub-terete due to the strongly revolute margins; lamina pubescent, green to greyish-green, margin entire, base and apex obtuse, veins inconspicuous, pubescence short, incane, strigose
Morphology Reproductive morphology Inflorescences
Inflorescences terminal, globose, dichotomously branched, to c. 5 cm long
Morphology Reproductive morphology Flowers
Flowers sessile, alternate, erect, aromatic. Calyx cylindrical, pale green; calyx lobes linear, fused only at the base or rarely up to the middle, strigose on both sides, 2.5 – 6.5 × 0.5 – 1 mm, free portion 0.5 – 5 mm long, apex acute or rarely obtuse
Morphology Reproductive morphology Flowers Corolla
Corolla infundibuliform, hispid outside, white with yellow throat, becoming purplish or violet; limb horizontally spreading, 6 – 12 mm wide, lobes rounded; tube almost twice as long as the calyx, 6 – 10 (− 12.5) mm long
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens included; filaments adnate to petals; anthers oblong, glabrous, base cordate, apex obtuse, 2 – 2.5 mm long, generally located above the apex of the stigmatic head or shortly overlapping it
Morphology Reproductive morphology Flowers Gynoecium Ovary
Ovary glabrous, c. 0.5 mm diam., with a basal nectar ring
Morphology Reproductive morphology Flowers Gynoecium Style
Style hispid, c. 1.3 – 1.7 mm long, longer than the stigmatic head
Morphology Reproductive morphology Flowers Gynoecium Stigma
Stigmatic head conic, 0.8 – 1.2 × 0.4 – 0.8 mm, column hispid
Morphology Reproductive morphology Fruits
Fruits dry, spherical, rugose, glabrous, dark brown, 1.5 – 2.5 mm diam., 4-seeded, not falling apart at maturity, dispersed together with the calyx
Morphology Reproductive morphology Flowers Pollen
Amb lobes not deep Endoapertures c. 5 μm diam., circular or somewhat lalongate and then contracted at the centre Exine thickness c. 1.3 μm, without differences between apocolpia and mesocolpia (from Ricardi 3134 in Marticorena 1968) Pollen prolate, 26 – 29.5 × 17 – 18.5 μm
Distribution
Coastal dry areas of the provinces of Chañaral (Región de Atacama) and Antofagasta (Región de Antofagasta) in Chile, 23°28' – 27°4'S (Map 2).
Ecology
A xerophyte of low areas next to the coast, on sandy substrates, alluvial foothills, and gravelly hillsides or on the eastern plains of the coastal Cordillera (see Johnston 1929), between sea level and 950 m. Never found in the fog zone. Locally dominant in the vegetation together with Nolana villosa (Phil.) I. M. Johnst. (Solanaceae), Frankenia chilensis C. Presl (Frankeniaceae), Gypothmanium pinifolium Phil. (Asteraceae), Heliotropium linariifolium (Heliotropiaceae) (Reiche 1911). It has also been reported from the coastal dunes, where the dominant species are Nolana mollis (Phil.) I. M. Johnst. (Solanaceae) and Tetragonia maritima Barnéoud (Aizoaceae) (Kohler 1970).
Conservation
Least concern (LC), see Luebert (2010).
Phenology

September to November.

Note

The epithet pycnophyllum refers to its dense foliage.

A very distinct species from the coastal Atacama Desert. In gross habit it resembles the other species of sect. Cochranea with conspicuous pubescence, but it differs from all other species of the section in its strongly revolute leaves and in its hispid style and stigmatic head, a combination of characters that is only present in the distantly related Old World species Heliotropium supinum L. and H. drepanophyllum Baker (Hilger 1987; Verdcourt 1988). In the phylogenetic analysis of Luebert & Wen (2008) this species was resolved as sister to the remainder of the section.

Vernacular
Palo negro (Spanish).
[KBu]

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation
Predicted extinction risk: not threatened. Confidence: confident
[AERP]

Uses

Use
Riedemann et al. (2006) suggest its potential use as an ornamental.
[KBu]

Sources

  • Angiosperm Extinction Risk Predictions v1

    • Angiosperm Threat Predictions
    • http://creativecommons.org/licenses/by/4.0
  • Herbarium Catalogue Specimens

    • 'The Herbarium Catalogue, Royal Botanic Gardens, Kew. Published on the Internet http://www.kew.org/herbcat [accessed on Day Month Year]'. Please enter the date on which you consulted the system.
    • Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/
  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2025. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 World Checklist of Vascular Plants. 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 Vascular Plants 2025. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0