Juanulloa
| Juanulloa | ||||||||||||
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Juanulloa mexicana |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Juanulloa | ||||||||||||
| Ruiz & Pav. |
Juanulloa is a plant genus of the family of the nightshade family (Solanaceae). It consists of eight recognized species thatare nativebetween Mexico and Bolivia . The generic name honors two people; the Spanish naval officer and geographer Jorge Juan (Jorge Juan y Santacilia) (1713-1773) and the Spanish scholar and admiral Antonio de Ulloa (Antonio Ulloay de la Torre-Guiral) (1716-1795).
description
Vegetative characteristics
Juanulloa species are in most cases lianas with a trunk length of 1.8 to 15 m, occasionally also bushes with a height of (rarely only 1.2) 2 to 5 m or trees with a height of 4 to 5 m. They grow epiphytically or terrestrially, the branches can reach a diameter of 4 to 5 cm. They hang or cling to the host plant with adherent adventitious roots . The pith usually contains irregular or spherically shaped stone cells . Trichomes are found on all parts of the plant above ground, but they fall off the trunk with age. Glandular trichomes can have a unicellular head (for example in Juanulloa ochracea ) or mostly multicellular heads (such as Juanulloa speciosa and Juanullo membranacea ). There are three different forms of non-glandular trichomes: simple trichomes consisting of two to twelve cells, branched trichomes with two to five branches, and tree-like trichomes with single-row or multi-row (only in Juanulloa verrucosa ) stems.
The leaves are membrane-like or leathery, have an egg-shaped, elliptical, or vice versa egg-shaped, pointed, tapering or tapering or in exceptional cases almost round shape. The leaf base is down on the petiole or rarely almost heart-shaped. The size is 6 to 18 (30) × 5 to 9 (13) cm, the length of the petioles is between (5) 10 and 20 (35) mm, only in Juanullo verrucosa the leaves are sessile or almost sessile.
Inflorescences and flowers
The umbel-shaped or grape-shaped inflorescences are terminally or laterally, usually consist of up to 18 or 20 flowers , rarely (as in Juanullo speciosa ) they are reduced to just one or two flowers. In this case, the inflorescence axis is also very short with only 0.5 to 1.5 cm, usually it is up to 55 cm in length, as in Juanullo verrucosa . The flower stalks are 5 to 35 mm long.
The flowers may or may not be fragrant, like Juanulloa ochracea . The calyx is in all cases shorter than the corolla tube, it is colored green, red or orange-red, urn-shaped. The thick or membrane-like, hairless or densely covered with tree-like shaped trichomes calyx is 1.3 to 4 cm long. It has three to five short, unevenly shaped tips or teeth or is divided into five similar segments almost to the base. However, these segments are not free because the trichomes sitting on the edges remain connected. The fleshy, tubular or funnel-shaped crown is slightly zygomorphic and usually 2.8 to 5 cm long. Exceptions are Juanulloa parviflora with only 1.9 to 2.2 cm long and Juanulloa speciosa with 6 to 12 cm long crowns. The five corolla lobes are about 1.8 to 2.3 mm long, triangular, oval or almost circular, they may or may not be eyed. Mostly they are a little wider than long, only in Juanulloa ferruginea they are elongated and 8 to 10 × 5 to 6 mm in size.
The stamens are usually within the corolla tube, only occasionally they are slightly beyond it. The stamens are attached at different heights in the lower half of the corolla tube, occasionally they are also above. The starting point of the stamens, the part of the crown located around this point and the stamens themselves are densely covered with trichomes. The dust bags are fixed on the back or the base of the back. Within the genus, anthers of different sizes occur: In Juanulloa speciosa they are the largest with 14 to 22 mm in length, the smallest has Juanulloa ferruginea with 4 to 5 mm in length. The pollen is medium-sized with a diameter of 31.5 to 40 µm, the pollen grain wall (exine) is scaly, 1.1 to 1.8 µm thick and somewhat thickened at the apertures. The two-leaved ovary is two-chambered, more or less almost conical in shape, the nectaries are pronounced, the stigma is saddle-shaped.
Fruits and seeds
The fruits are egg-shaped or almost round berries that are (1.5) 2 to 4 × (1) 1.8 to 3 cm in size. They are surrounded by an enlarging calyx, the pericarp is thick or thin, usually yellow. The seeds are briefly kidney-like or boomerang-shaped, 2.5 to 5 × 1.5 to 3 × 1 to 1.2 mm in size. The surface is finely structured like a net, the embryo is mostly curved in the seed, only in Juanulloa speciosa it is ring-shaped. The cotyledons are elongated, close-fitting and thicker, but shorter than the rest of the embryo. The endosperm is not very pronounced.
Occurrence and locations
The eight species occur neotropically , some of them are myrmekophil (dependent on ants) and grow in the rainforests of the Andes . The distribution area extends from southern Mexico to Bolivia and is at altitudes between 300 and 3,500 m. The species with the northernmost distribution area is Juanullo mexicana , in the south the species Juanulloa membranacea and Juanulloa verrucosa form the limit of the distribution area.
Systematics
The genus consists of eight recognized species:
- Juanulloa ferruginea Cuatrec.
- Juanulloa membranacea Rusby
- Juanulloa mexicana (Schltdl.) Miers
- Juanulloa ochracea Cuatrec.
- Juanulloa parasitica Ruiz & Pav.
- Juanulloa parviflora (Ducke) Cuatrec.
- Juanulloa speciosa (Miers) Dunal
- Juanulloa verrucosa (Rusby) Hunz. & Subils
The type species is Juanulloa parasitica .
literature
- Armando T. Hunziker: The Genera of Solanaceae . ARG Gantner Verlag KG, Ruggell, Liechtenstein 2001. ISBN 3-904144-77-4 .
Individual evidence
- ↑ Lotte Burkhardt: Directory of eponymous plant names . Extended Edition. Botanic Garden and Botanical Museum Berlin, Free University Berlin Berlin 2018. [1]
