Iochroma orozcoae A.Orejuela & S.D.Sm., 2023

Orejuela, Andres, Smith, Stacey D., Villanueva, Boris & Deanna, Rocio, 2023, A new species of Iochroma Benth. (Solanaceae) from the eastern Andes of Colombia, PhytoKeys 232, pp. 133-144 : 133

Iochroma orozcoae A.Orejuela & S.D.Sm. sp. nov.

Figs 1 , 2

Type.

Colombia. Cundinamarca: vía Ubate-Lenguazaque , carretera sin pavimentar, antes del sector conocido como las balsas, 5°20'2.5"N, 73°43'23"W, 2600 m elev., 27 August 2017, A. Orejuela & J. Castillo 2942 [holotype: JBB, (accession # JBB30649 ); isotypes: COL, HUA, HEAA] .

Diagnosis.

A Iochroma baumii S.D.Sm. & S.Leiva affinis, sed paucarum inflorescentiae in ramum prope apicem germinis dispositae sunt, quae 1 ad 4 (-8) floribus, flores minores 1.5-2 cm longi; corolla quinque lobis constat, et fructus viridis-flavus colore maturo differt.

Description.

Shrub 1.5-3 m tall; young stems pubescent with branched hairs, older stems with corky bark. Leaves alternate, simple, (2.1-) 5.3-11.6 × (1.2-) 2.2-5.5 cm, elliptic; adaxial surface glabrescent; abaxial surface densely pubescent with branched hairs; base cuneate; margins entire; apex acute to attenuate; petioles (0.4-) 0.8-2.5 (-3) cm. Inflorescences axillary on young branches near the shoot apex, 1 to 4 (-8)-flowered; pedicels 1.1-1.7 (-2) cm in flower, 1.6-2.4 cm in fruit, terete, pendulous, densely pubescent with many-branched hairs. Calyx 6-7 × 5-6 mm, tubular to slightly urceolate, green, with few to many-branched hairs, with five broadly triangular lobes, ca. 0.8 × 2-2.5 mm in flower, shallowly divided in flower, deeply divided in fruit, in fruit, the calyx accrescent 9-10 × 10-11 mm, lobes 4-5 × 7-8 mm; corolla 15-20 × 4-4.5 mm at anthesis, tubular, flaring at the mouth, the exterior deep blue-purple, with many simple or occasionally branched hairs, the pubescence increasing towards the mouth, the interior deep blue-purple, glabrous, the lobes 5, 2.6-2.8 × 2.2-2.6 mm, acute to the apex and cucullate; stamens 5, included; filaments with simple and branched hairs, fused to the corolla at 3.8-5.2 mm from the base, with the free portion 7-11.4 mm long; anthers 3.5-5.2 × 1.3-1.7 mm, oblong, cream, longitudinally dehiscent; ovary 3.6-4.8 × 1.7-2.5 mm, pyriform, glabrous, with a yellow nectariferous disc, style 13-15 mm, the stigma green, clavate, bilobed. Berry 12-14 × 9-11 mm, slightly ovoid, greenish-yellow at maturity with 20 to 30 sclerosomes, the basal 3/4 enveloped in the accrescent fruiting calyx; seeds 110 to 170 per berry, 2-2.1 × 1.7-1.9 mm, yellow, reniform.

Etymology.

This species is named in honour of Clara Inés Orozco Pardo, an Associate Professor of botany at the Instituto de Ciencias Naturales of the Universidad Nacional de Colombia. Her dedication to the understanding of Colombian flora, particularly in the fields of taxonomy and systematics of the Brunelliaceae and Solanaceae families, has been remarkable. She has also played a crucial role in mentoring several Colombian botanists, including the first author of this paper.

Distribution and ecology.

Iochroma orozcoae is found in the Municipality of Lenguazaque, Cundinamarca Department, in the eastern Andes of Colombia, in the surroundings of the rock formation known as the Farallones de Lenguazaque, which is situated at an elevation of 2600 m (Fig. 3 ). The Farallones de Lenguazaque exhibit a vegetation type characteristic of high-altitude mountain ecosystems. The primary vegetation in this area comprises high Andean forest relicts of native forest, secondary forest, plantations of foreign species, grasslands and subparamo vegetation.

Phylogeny.

Iochroma orozcoae belongs to the “F” clade ( Smith and Baum 2006) containing other northern Andean species ( I. gesnerioides , I. fuchsioides , I. calycinum Benth. and I. baumii ) with high bootstrap support (96%). The red-flowered species ( I. gesnerioides and I. fuchsioides ) are separated from the blue-flowered species ( I. calycinum , I. baumii and I. orozcoae ), but that split is not well supported. Amongst the blue-flowered members of the “F” clade, I. baumii and I. orozcoae appear as sister taxa with 59% bootstrap support (Fig. 4 ).

Preliminary conservation status.

Iochroma orozcoae is classified as a data-deficient species (DD) due to the limited information on its abundance and distribution that is inadequate for comprehensively assessing its conservation status. The species has been collected only on four occasions, suggesting probable local rarity. The initial collection was made by José Celestino Mutis in 1783 from an unknown locality, followed by another by Oscar Haught in 1947 from Lenguazaque, Cundinamarca and a couple of recent collections by the first author from the same locality as Haught’s collection. Despite conducting an extensive search through specialised literature, the drawings of the Royal Botanical Expedition of the New Kingdom of Granada (1783-1816) and Mutis’ journals, the precise location of Mutis’ first collection remains unknown. We infer that the distribution of the species may be highly restricted, based on the small number of known collections from the same locality. Assumptions regarding its scarcity and restricted distribution, however, require further studies. Living plants of I. orozcoae originated from seeds, collected at the type locality and are conserved ex situ in the living collections of the Jardín Botánico de Bogotá.

Discussion.

Our phylogenetic analyses offer strong support for the placement of I. orozcoae in the northern Andean “F” clade from Smith and Baum (2006). However, it differs from all other species in its broader and denser pubescence on both its vegetative and reproductive parts, small corollas and less abundant inflorescences with fewer flowers (Figs 1 , 2 , 5 ). The new species shares with I. baumii and I. calycinum intensely pigmented flowers, which are variously described as purple, violet or blue (Fig. 5 ). In contrast to I. baumii and I. fuchsioides which have corollas with ten teeth (five major lobes and five smaller teeth alternating with the lobes), I. orozcoae has corollas with five teeth corresponding to the lobes. Iochroma orozcoae is morphologically more similar to I. baumii . However, the new species is easily separated from I. baumii because it presents smaller flowers, 1.5-2 cm long (versus 2.8-4.5 cm long), only a few inflorescences per branch, located near the shoot apex with 1 to 4 (-8) flowers (versus masses of inflorescences per branch in clusters typically on older, often leafless branches, rarely near the shoot apex, with 6 to 12 flowers per inflorescence), corolla with five lobes (versus a 10-lobed corolla) and, while the fruits of I. orozcoae ripen in greenish-yellow colour, those of I. baumii are greenish-purple when ripe. A detailed comparison between I. orozcoae and the remaining species in the “F” clade can be found in Table 1 .

The rediscovery of I. orozcoae over two centuries since the first collection by José Celestino Mutis in 1783 underscores the immense importance of historical collections in documenting and describing botanical diversity and their potential contribution in setting conservation priorities within biodiverse regions. This is a widely-debated topic that is gaining increasing attention over time ( Besnard et al. 2018; Albani Rocchetti et al. 2021; Vargas et al. 2023). In the case of I. orozcoae , the presence of the long undetermined specimens spurred renewed collecting efforts in the eastern Andean cordillera of Colombia, which continue to be the source for many newly-described taxa, some of which have remained elusive for many years (e.g. Granados-Tochoy et al. (2007)). Given the challenges associated with locating and collecting narrow endemics such as I. orozcoae , it will often be necessary to base descriptions on scant material so that perhaps in future, the timespan between additional collections of new species does not span centuries, an important consideration in the context of the ongoing efforts to conserve biodiversity.

Additional specimens examined.

Colombia. Cundinamarca: Ubate - Lenguazaque Highway, 2600 m elev., 16 September 1947, O.L. Haught 6188 (COL, US); Lenguazaque, vía Ubate-Lenguazaque , antes del sector Las Balsas , en cercanías de los farallones de Lenguazaque 5°20'0.25"N, 73°43'23"W, 2600 m elev., 04 September 2021, A. Orejuela 3407 with H. Mendoza, J. Castillo. V. Luna, C. Luna & M. Mora (JBB, COL, HEAA) ; Colombia, sin. Loc., 01 January 1783, J.C. Mutis 636 (COL) .

Figures

Figure 1. Iochroma orozcoae A. Orejuela & S. D. Sm. A flowering branch B inner corolla surface, showing the stamens C flower. Detail is shown for the simple and branched hairs on the corolla D gynoecium E, F details of the stamens and anthers G fruit with persistent calyx H seed. Drawn by Omar Bernal from Orejuela & Castillo 2942 & Orejuela et al. 3407.

Figure 2. Iochroma orozcoae A. Orejuela & S. D. Sm. A young branch B stem detail C, D leaf detail showing the abaxial and adaxial sides E floriferous branch with flowers in lateral view F floriferous branch with a flower in frontal view G fruits showing the accrescent appressed calyx. Photos by Andres Orejuela.

Figure 3. Geographic distribution of I. orozcoae (orange circles) and closely-related species in the " F " clade with presence in Colombia, including I. baumii (red circles), I. gesnerioides (green circles) and I. fuchsioides (blue circles).

Figure 4. Maximum Likelihood phylogeny of Iochrominae including the new species, I. orozcoae. Relationships based on three nuclear markers with taxon sampling following Deanna et al. (2019). Physalideae outgroups from Smith and Baum (2006) (Physalis peruviana L., Leucophysalis grandiflora (Hook.) Rydb., Witheringia solanacea L'Her., Tubocapsicum anomalum (Franch. & Sav.) Makino and Deprea sachapapa (Hunz.) S. Leiva & Deanna) were used to root the tree and pruned for visual purposes. Bootstrap values above 50 % are shown. Nomenclatural rearrangements are underway for Iochrominae (Deanna et al., unpublished) given the non-monophyly of the genera. The clade denoted with an asterisk will remain assigned to the genus Iochroma as it contains the type species (Iochroma cyaneum (Lindl.) M. L. Green ex G. H. M. Lawr. & J. M. Tucker) and most of the species described in this genus.

Figure 5. Species within the " F " clade of Iochroma that are closely related to I. orozcoae A flowering branch of I. fuchsioides observed at Parque Recreacional y Bosque Protector Jerusalem, Malchingui, Ecuador B flowers of I. gesnerioides photographed at the Jardin Botanico de Bogota, Colombia C flowers of I. calycinum at the reserva Otonga, Sigchos, Cotopaxi, Ecuador D flowers and fruits of I. baumii observed close to the type locality in Papallacta-Baeza road, Quijos, Napo, Ecuador E flowering branch of I. baumii from populations from La Pastora, Caldas, Colombia F fruits of I. gesnerioides photographed at the Jardin Botanico de Bogota, Colombia G fruits of I. fuchsioides photographed close to Pasto, Narino, Colombia. Photos by Andres Orejuela (B, C, F, G), Hal Mitchell (D), Nathaly Obregon (A) and Juan David Tovar (E).