Heliotropium floridum Clos

First published in C.Gay, Fl. Chil. 4: 457 (1849)
This species is accepted
The native range of this species is Chile (Atacama, Coquimbo). 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, ad Coquimbo, 1839, C. Gay 1182 (holotype G-DC [photo F neg. no. 7769: F, GH, NY, US, photo SGO 67284]; isotypes GH, P not seen [digital photograph, fragm. F 515902, F 970065, photo MSB]) probable isotypes [Chili, Gay (1834 – 1842)] G, [Chili Gay] K, P not seen [digital photograph, photo MSB]).
Morphology General Habit
Erect shrubs, 0.15 – 0.8 (− 1) m tall, with ascending branches, densely foliose to the base of the inflorescence
Morphology Stem
Stems and foliage strigose
Morphology Leaves
Leaves alternate, solitary or grouped in fascicles of up to 13 leaves, sessile, succulent linear to linear-spathulate, 6.5 – 30 (− 40) × 1 – 9.5 (− 11) mm; lamina strigose, green or greyish-green, margin entire, revolute, base attenuate, apex obtuse, with only the main vein conspicuous
Morphology Reproductive morphology Inflorescences
Inflorescences terminal, elongate, dichotomously branched, congested, to c. 6 (− 9) cm long
Morphology Reproductive morphology Flowers
Flowers sessile or shortly (< 1 mm) pedicellate, alternate, erect
Morphology Reproductive morphology Flowers Calyx
Calyx cylindrical, green or brownish-green; calyx lobes linear, fused only at the base or free, strigose on both sides, 2.5 – 5.5 × 0.5 – 1.5 mm, free portion 2 – 5.5 mm long, apex acute
Morphology Reproductive morphology Flowers Corolla
Corolla infundibuliform, sparsely strigose, dull white with yellow to orange throat, becoming bluish at late anthesis; limb horizontally spreading, 5.5 – 11.5 mm wide, lobes rounded; tube longer than the calyx, 5 – 9 mm long
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens included or exserted at late anthesis; filaments adnate to petals; anthers oblong-lanceolate, glabrous, base cordate, apex acute, c. 1.2 – 1.5 mm long, overlapping the stigmatic head
Morphology Reproductive morphology Flowers Gynoecium Ovary
Ovary glabrous, subglobose, 0.4 – 0.6 mm diam., with a basal nectar ring
Morphology Reproductive morphology Flowers Gynoecium Style
Style glabrous, c. 1.5 – 2 mm long, longer than the stigmatic head
Morphology Reproductive morphology Flowers Gynoecium Stigma
Stigmatic head conic, elongate, bilobate, c. 0.7 – 1 × 0.7 mm
Morphology Reproductive morphology Fruits
Fruits dry, ellipsoid, rugose, glabrous, brown, c. 2.5 × 1.5 mm diam., falling apart at maturity into two 2-seeded nutlets, c. 1.5 × 1.5 mm diam. Figs 1, 2Q and 3P.
Distribution
Coastal range of the provinces of Chañaral, Copiapó, Huasco (Región de Atacama) and Elqui (Región de Coquimbo), Chile, between 26°2'S and 29°15'S (Map 12).
Ecology
Coastal dunes, rocky hills and sandy plains, 0 – 270 m. In the sandy plains the vegetation is usually a scrub with columnar cacti, where Heliotropium floridum can be dominant together with Atriplex clivicola (Amaranthaceae) and Eulychnia breviflora (Cactaceae). In the coastal dunes it can also be dominant together with Chuquiraga ulicina (Hook. & Arn.) Hook. & Arn. (Asteraceae) and Cristaria glaucophylla Cav. (Malvaceae).
Conservation
Least concern (LC), see Luebert (2010).
Phenology

September to November.

Note

The epithet floridum refers to its congested inflorescence.

This species might be locally confounded with Heliotropium longistylum and H. megalanthum (see discussion under these species). In herbaria it is frequently confounded with H. linariifolium. The latter has orange flowers and decumbent habit (vs white flowers and erect habit in H. floridum), but these characters are difficult to see in herbarium specimens. Both species overlap their geographic areas in the coastal range between the towns of Caldera and Chañaral, and material coming from that area is usually difficult to distinguish in herbarium specimens, unless there is indication of flower colour or habit.

Heliotropium floridum can also be confounded with H. philippianum, with which it does not overlap in geographic range. H. philippianum is distributed from Paposo (c. 25°S) northwards, while H. floridum occurs from Chañaral (c. 26°S) southwards. H. philippianum is a shrub usually taller than 0.6 m, while H. floridum is almost always shorter. Both species were recovered in an unresolved clade in the phylogeny of section Cochranea (Luebert & Wen 2008).

[KBu]

Uses

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

Sources

  • Herbarium Catalogue Specimens

    • 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 2024. 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 2024. 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