Capsicum neei

Overview

Capsicum neei is a wild species of pepper native to Bolivia, particularly the mountainous forests of Chuquisaca and Santa Cruz. It is a rather slender, loosely branched shrub that grows beneath forest vegetation, not a farmed variety of the familiar red or green chilli. Its flowers are small and yellow, its berries become red when ripe, and its most reliable identifying feature is hidden just behind each flower: a green calyx with ten prominent veins and ten narrow projections.

The species was named in 2019 by Gloria E. Barboza and Ximena Reyes, after research bringing together herbarium specimens, recent field collections and DNA evidence. The name celebrates Mike Nee, a botanist whose extensive work on the nightshade family in Bolivia helped bring the plant to attention. Its closest genetically demonstrated relative in the 2019 study was Capsicum caballeroi, while its yellow flowers make it easy to mistake for Capsicum minutiflorum until the flower stalk and calyx are examined.

One important chapter of the species' history unfolded after its description. The first paper could describe red berries but had no mature seeds for study and did not establish whether the fruit was hot. The major 2022 monograph later documented pungent berries with pale yellow to nearly white seeds and revised its preliminary conservation assessment to Least Concern. These findings make C. neei a useful example of how botanical knowledge grows through repeated fieldwork.

Scientific name

Capsicum neei Barboza & X. Reyes

Family

Solanaceae

Native country

Bolivia

Recorded departments

Chuquisaca & Santa Cruz

Evolutionary group

Bolivian clade

Growth habit

Slender shrub, usually 0.7–2 m

Earliest cited collection

1 January 1995

Type collected

16 December 2017

First description

16 January 2019

Flower

Yellow, star-shaped

Flower calyx

10 veins, 10 unequal teeth

Ripe berry

Red; approximately 4–7.5 mm

Pungency

Pungent (2022 study)

Mature seeds

Pale yellow to nearly white

Mainly recorded altitude

1,100–1,750 m

Conservation

Preliminary Least Concern (2022)

Discovery & naming

The scientific story of C. neei began long before the name appeared in print. Among the older specimens cited in its original description is a collection gathered by British botanist John R. I. Wood on 1 January 1995, along the Río Limón Valley between Padilla and Monteagudo in Chuquisaca. A series of other collections followed during the early 2000s, including material from the Serranía del Iñao, Yahuañanca and Kaska Orcko mountain areas. Some specimens were preserved in Bolivian and international herbaria years before botanists formally described the species.

It attracted the attention of Mike Nee, an American botanist and specialist in the nightshade family. Nee undertook extensive collecting and identification work in Bolivia and recognised several herbarium specimens of this plant as an unusual pepper, possibly representing a species not yet described. The published explanation of the scientific name specifically honours his work, rather than referring to a geographic place or a physical feature of the plant. The ending -ii is a common botanical way of forming a name dedicated to a person.

A decisive collection was made on 16 December 2017, when Gloria E. Barboza and colleagues collected specimen 4927 in the province of Hernando Siles, Chuquisaca, about 4.1 km beyond a bridge near Monteagudo. That flowering specimen became the holotype, the preserved reference plant permanently associated with the scientific name. The holotype was deposited at the Herbario Nacional de Bolivia (LPB), with duplicate specimens at CORD in Argentina and NY in the United States. The exact locality and collection number provide a verifiable link between the published name and a real population in the wild.

On 16 January 2019, a five-author paper in PLOS ONE formally described four new Andean Capsicum species: C. benoistii, C. piuranum, C. longifolium and C. neei. Its authors were Gloria E. Barboza, Carolina Carrizo García, Segundo Leiva González, Marisel Scaldaferro and Ximena Reyes; the naming authors for C. neei were specifically Barboza and Reyes. Alongside the description came a detailed botanical drawing, plant photographs, a distribution map and a DNA-based study of its relationships.

The larger 2022 monograph of all wild and cultivated Capsicum then expanded the account. New fruit photographs, mature seed observations and additional anatomical evidence made it possible to compare C. neei more fully with other Bolivian peppers. The plant has therefore had two major documentary milestones: its formal recognition in 2019 and its more complete modern botanical treatment in 2022.

Plant & leaves

Capsicum neei usually forms an upright shrub around 70 cm to 2 metres tall, occasionally reaching about 3 metres. Its overall structure is comparatively light and open. The branches are slim, fragile and rather loosely spaced, rather than creating a dense, compact bush. Young shoots are green with slight lengthwise ridges and a scattering of very fine hairs; as the plant ages, the stems become light brown and acquire a few oblong lenticels, small pores visible in the bark.

The foliage is thin and flexible, technically described as membranous. As in several wild peppers, the branches produce pairs of leaves at some nodes. These paired leaves are not identical, but neither are they as dramatically unequal as the foliage of some Andean species. The larger blades are commonly 6.7–11 cm long and 2.1–4 cm wide, occasionally a little outside those measurements. They are broadly elliptical or egg-shaped, with smooth margins, tapered bases and pointed tips.

The smaller leaf of a pair is usually about 2.7–4.6 cm long, sometimes reaching 6 cm, and is often only 1.2–1.8 cm wide. Both have short stalks: the larger leaves are normally held on petioles around 3–8 mm long, while the smaller ones commonly have stalks of 2–5 mm. A large leaf often has three or four prominent side veins on either side of its central vein; its smaller neighbour usually has two or three.

Under close inspection, leaf surfaces and edges can carry scattered pale, simple hairs measuring roughly 0.2–0.5 mm. The botanists who described the species noted that each of these short hairs consists of several cells. They are most useful for detailed identification under a lens, but the general appearance is of a thin-leaved, lightly hairy woodland shrub. In the lower, shaded forest layer, this foliage makes a much less conspicuous display than the broad, lush leaves often seen on cultivated chillies.

From a distance, its growth may be mistaken for several other members of the nightshade family. The strongest evidence comes when the branching pattern, leaf pairs, delicate flowers and persistent calyx are considered together, especially on living plants where the colour and position of the flowers are still visible.

Flowers & remarkable ten-toothed calyx

The small flowers are one of the most attractive features of Capsicum neei. They usually occur in groups of two to four at a leaf joint, although a single flower may occasionally be seen. At first glance, a flowering branch can appear to carry solitary blossoms because the earlier buds or flowers in the cluster may have dropped, leaving only tiny scars. The individual flowering stalks are slender, mostly 8–15 mm long, green and hanging downward without a sharp elbow-like bend at flowering.

The buds start out greenish to pale yellow and open into delicate yellow, five-pointed stars. A flower's corolla is typically around 8–10 mm long, sometimes a little smaller, with five spreading to somewhat erect lobes. The flower is almost entirely yellow, but some blossoms have faint brownish-green or greenish-yellow spots near the throat. Seen from the front, the five petals frame a light-coloured central style and five light-yellow anthers.

The feature that botanists look for first is the calyx, the green structure holding the flower at its base. In C. neei it is strongly marked by ten raised veins and bears exactly ten narrow, unequal projections. Five longer teeth emerge close to the rim of the cup and are usually 0.9–1.75 mm long. Between them lie five shorter teeth, mostly 0.2–0.8 mm long, originating a little farther down the cup. The result is an alternating ring of long and short points, unlike the simpler five-toothed calyx of many other peppers.

The calyx also has a complex covering of hairs. Fine non-glandular hairs occur on the outer surface, while the inner surface has tiny glandular hairs. The flower stalk itself may carry both types. Under magnification, these structures provide diagnostic details, and the original 2019 illustration drew several different hairs individually to record their form.

Inside each flower are five stamens with short cream-coloured filaments, approximately 1.4–1.75 mm long, and yellow anthers about 1.8–2 mm long. The pale green ovary is small and rounded, with a nectar-producing ring at its base. A slender cream-coloured style extends towards the centre of the flower and ends in a small, slightly divided green stigma. These measurements may seem minute, but they are central to identifying closely related wild species whose fruits can otherwise look almost identical.

Fruit, heat & seeds

After flowering, C. neei produces small, nearly round berries, usually around 4–7.5 mm in diameter. They start green and turn red when fully ripe. The skin is smooth, and the persistent calyx remains wrapped around the fruit's attachment point, with its short narrow teeth spreading outward. Compared with the larger chillies sold in shops, these berries are tiny, but they are very typical of many wild South American peppers.

The fruit stalks lengthen as the berries develop, commonly reaching around 18–23 mm in the original description. The 2019 paper described the fruit-bearing stalks as hanging, while later material and the 2022 identification key account for fruit stalks held more upright. Flower stalk position is the more consistent identification feature: the flowers themselves hang on stalks without the pronounced bend seen in C. minutiflorum.

The later 2022 monograph documented the ripe fruit as pungent. This matters because the original 2019 description had only provisional information about the fruit's internal structure. There is no defensible species-wide Scoville rating in the cited botanical treatments, so the most useful account of its heat is simply that the fruit is hot rather than non-pungent, without assigning it an invented SHU figure.

The mature seeds are particularly interesting. They are pale yellow to almost white, approximately 4–5 mm long and 3–4.25 mm wide in the 2022 identification key. The seed surface is relatively smooth, with a more net-like pattern around the margin. This is an unusually light seed colour compared with the dark brown or black seeds found in many Andean forest peppers. The later published photo plate includes a ripe berry cut open, showing the pale seeds against its red flesh.

Follow-up anatomical study also identified enlarged cells within the fruit wall, a trait shared with several relatives in the Bolivian evolutionary group. Those features help connect the field appearance of the plant with its deeper botanical relationships. When a ripe berry is examined together with its ten-toothed calyx and the leaf and flower characters, identification becomes much more reliable than by using fruit colour alone.

Range, habitat & seasonal life

Capsicum neei is endemic to Bolivia. Botanical collections place it mainly in the south-eastern mountains of the country, in the departments of Chuquisaca and Santa Cruz. Much of the documented range lies in the Serranías del Iñao, Yahuañanca and Khaskha Orkho, with additional records from the Yungas of Santa Cruz. The species is not known as a widespread lowland pepper; its distribution follows particular mountain forests and their margins.

Its principal environment is the Boliviano-Tucumano Forest, a forest system associated with the eastern slopes and foothills of the south-central Andes. Plants are reported from the understorey of cloud-influenced and seasonally deciduous forest, often on the lower parts of slopes. Most records come from around 1,100–1,750 metres above sea level. One specimen cited in the original paper was collected higher, around 2,190 metres near La Yunga de Mairana in Santa Cruz, showing that those main-range elevations are not an absolute limit.

The vegetation around it includes members of the walnut, laurel, myrtle and legume families, along with ferns and mosses. This helps explain the plant's relatively delicate leaves and tall, airy branching habit. Rather than growing on a bare, sun-baked site, it is usually found among other plants, beneath forest cover where the climate and light differ substantially from open-field chilli production.

Field and herbarium observations document flowers and fruits between October and May. Those dates reflect collected plants in the Bolivian countryside, with rainfall, altitude and local forest conditions influencing seasonal activity. Fruiting branches can carry berries at different stages, and the 2022 photographs record their transition from green to red.

Several collections come from the area now protected as the Parque Nacional y Área Natural de Manejo Integrado Serranía del Iñao. These sites are valuable for more than their pepper populations: they conserve a larger and complex ecosystem of mountain forests, many of whose plants are naturally restricted in distribution. Protecting that setting is central to keeping C. neei in the wild.

Identification & related species

The species most easily confused with C. neei is Capsicum minutiflorum. Both are native Bolivian wild peppers with yellow star-shaped flowers and red ripe berries. The difference becomes clear when the flower stalks and calyx are inspected. In C. neei, the flower stalk hangs and is not sharply bent; the calyx carries ten raised veins and ten unequal teeth. In C. minutiflorum, the flower stalk is generally upright and distinctly bent, while the calyx has five short, approximately equal teeth and much weaker visible venation.

The distinction is not a trivial technicality. These features were singled out in the original 2019 diagnosis as the simplest way to separate the two species, even where their leaf shape, flower colour and berry colour overlap. The number of calyx projections is especially useful when viewing preserved herbarium specimens where the colours have faded.

DNA analysis gave another result. The original authors placed C. neei within the Bolivian clade, a group of wild peppers including C. caballeroi and other Bolivian species. In the 2019 phylogenetic analysis, C. caballeroi was the closest sampled relative of C. neei. The two share their broad evolutionary placement but differ in the details of flowers, calyx structure and overall appearance.

A further plant encountered in the same broad region is the widespread wild Capsicum baccatum var. baccatum. It often bears white flowers with greenish-yellow markings, with flower stalks that bend at flowering, and has five approximately equal calyx teeth. These features help separate it from the yellow-flowered, ten-toothed C. neei, even though both may eventually produce small red berries.

For field identification, the best combination is an open, thin-branched shrub; subtly paired leaves; yellow star-like flowers; drooping unbent flower stalks; a strongly ribbed, ten-toothed calyx; and small red ripe fruit. Using several characters together avoids the common problem of assuming that two wild peppers are the same simply because their berries look alike.

Genetics & botanical research

The 2019 description went beyond measuring and illustrating a new plant. Researchers also used DNA sequences to compare its relationships with other wild peppers. Their study combined four regions from chloroplast DNA with the nuclear gene waxy, allowing them to examine branches within the pepper family that are difficult to sort out from appearance alone.

In that analysis, C. neei was resolved near C. caballeroi in the Bolivian group. The authors noted that the larger Bolivian grouping was not uniformly well supported in every part of their evolutionary tree, in part because of the position of C. coccineum. That distinction is important: the close connection between the sampled C. neei and C. caballeroi was a result of the study, while relationships among every member of the broader group remained an active research question.

The 2019 paper specifically reported chromosome counts for two other newly described species, C. longifolium and C. piuranum; C. neei was included in the DNA work rather than that chromosome-counting part of the study. For its own identification, the most substantial direct evidence therefore comes from flower anatomy, specimen comparisons and its DNA placement, rather than an assumed chromosome number.

The expanded 2022 monograph drew on a much wider review of wild and cultivated Capsicum. It added detailed fruit photographs, the presence of giant cells in the pericarp and the description of pale mature seeds. The fruit was also described as pungent. These observations helped connect the original field-based description with the fruit-anatomy features seen in other related Bolivian peppers.

This sequence of studies highlights why the date of a species name is not the end of its discovery story. A plant can be formally named using flowering material, while later collections in fruit fill in major features that are essential to understanding how it compares with neighbouring species. Capsicum neei provides a particularly clear example because the 2019 and 2022 publications can be read side by side.

Conservation & changing assessments

The original 2019 paper proposed Near Threatened (NT) for C. neei under IUCN geographic-range criteria. At that stage, the authors calculated an extent of occurrence of about 16,912 km² and an area of occupancy of about 44 km². Those two measurements represent different things: the first is the broader outline surrounding the recorded sites, while the second estimates the much smaller area in which the plant is actually documented. The authors noted pressures on habitat but also recorded plants in more than ten localities, including protected forest.

In the comprehensive 2022 monograph, new calculations gave an extent of occurrence of about 13,880 km² and an area of occupancy of 48 km². Despite the small occupied area, the authors proposed Least Concern (LC), citing its records at more than ten localities, repeated collections across roughly two decades, and populations within the protected Serranía del Iñao area and nearby forest. Their view was that the known distribution did not, at that time, indicate the severe decline required for a threatened category.

This is a change in the published preliminary scientific assessments, not proof that forest loss stopped or that the species could never face threats. It is also not presented here as a separately verified official IUCN Red List listing. Its distribution remains restricted to parts of Bolivia, and the persistence of healthy forest habitat is essential to the plants recorded there.

For a wild species with no comparable large-scale cultivated population, field collections and secure natural habitat matter especially. Preserved specimens document where the plant occurred; newer observations can reveal whether those populations remain present. The lasting value of C. neei is both in its own distinctive biology and in the diversity it represents among the lesser-known relatives of domesticated chillies.