Acnistus arborescens

''Iochroma arborescens'' is a species of flowering plant in the genus ''Iochroma'', belonging to the nightshade family Solanaceae. Formerly it was considered the single species in the monotypic genus ''Acnistus''. Common names include gallinero (= 'henhouse'), mata-gallina (= 'chicken-killer'), fruta-de-sabiá (= 'thrush-fruit'), hollowheart, wild tobacco, siyou, bastard sirio, ''galán arbóreo'', ''tabaco de monte'' (= 'mountain tobacco'), ''nigüito'', ''marieneira'', ''güitite'', and ''tabak djab'' (= 'devil's tobacco').Francis, J. K
''Acnistus arborescens''.
USDA Forest Service, International Institute of Tropical Forestry, Jardín Botánico Sur, Puerto Rico.

Etymology

The former genus name ''Acnistus'' has been claimed to be a compound of the Greek prefix 'a-' and Latin 'cnistus' misreading of Latin 'crista' - a crest ? which would give the meaning 'without a crest'. A more likely derivation, however, is from the single Homeric Greek word άκνηστις (pron. 'akneestis' / 'aknistis'), meaning 'backbone', possibly in reference to the backbone-like, white, longitudinal stripes running up the centre of each green patch on the exterior of the corolla.

Publication

The genus name ''Acnistus'' was published by Austrian botanist Heinrich Wilhelm Schott in ''Wiener Zeitschrift für Kunst, Litteratur, Theater und Mode'', (- abbreviation :'Wiener Z. Kunst' - a journal featuring botanical descriptions and illustrations published between the years 1817 and 1848 ) : Vol. 4: 1180 on the 28th of November of the year 1829.
The binomial ''Acnistus arborescens'' (L.) Schltdl. was published by German botanist Diederich Franz Leonhard von Schlechtendal in the journal Linnaea, Vol. 7 (pps. 67–68) in the year 1832.

History of classification

The case of ''Acnistus arborescens'' is remarkable, considering the vicissitudes of its long and varied taxonomic history; it has received 29 botanical names with 17 different epithets associated to 6 generic names.- Armando HunzikerArmando T. Hunziker: The Genera of Solanaceae. A.R.G. Gantner Verlag K.G., Ruggell, Liechtenstein 2001. pps. 199–202.

Since Hunziker made the observation quoted above, the case of ''Acnistus arborescens'' has grown yet more remarkable : the Plant List enumerates no fewer than 11 genera to which the plant has been assigned since it first became known to science :
''Acnistus'', ''Atropa'', ''Brachistus'', ''Capsicum'', ''Cestrum'', ''Dunalia'', ''Ephaiola'', ''Eplateia'', ''Fregirardia'', '' Lycium'' and ''Pederlea''. The brief assignment to the genus ''Cestrum'' is particularly wide of the mark, given the fact that the generic name ''Cestrum'' actually furnished the name of the subfamily Cestroideae (''Acnistus'' belongs to the subfamily Solanoideae, not Cestroideae. ''Atropa'' is an exclusively Old World genus. The obsolete genus ''Fregirardia'' formerly contained various ''Capsicum'' species and a single species of ''Cestrum''; while the obsolete genera ''Ephaiola'', ''Eplateia'' and ''Pederlea'' are referable solely to ''Acnistus arborescens''. Of the genera in the list above, ''Dunalia'' is the genus most closely related to Acnistus, belonging as it does to the same tribe within the Solanoideae – namely Physaleae (named for ''Physalis'').Page ''Acnistus arborescens'' The Plant List http://www.theplantlist.org/tpl1.1/record/kew-2618239 retrieved 9.42 a.m. 14/2/19
Indeed, Hunziker draws attention to the fact that, such is the closeness of the relationship between ''Acnistus'', ''Dunalia'' and ''Iochroma''...

...these three genera were merged by Sleumer, but soon after Hunziker called attention to the elaborate stapet of Dunalia and its taxonomic importance as well. – Armando Hunziker

Note : the uncommon botanical term ''stapet'' (employed above by Hunziker in reference to the genus Dunalia) is used to designate congenital fusion of stamens to petals, which is found commonly in association with sympetaly in core eudicots. However, this phenomenon is rarely found in rosids The word ''stapet'' is a portmanteau of sorts, combining as it does abbreviated forms of the words ''stamen'' and ''petal'' ].

List of 50 synonyms by genus

*''Acnistus aggregatus'' (Ruiz & Pav.) Miers
*''Acnistus benthamii'' Miers
*''Acnistus campanulatus'' (Lam.) Merr.
*''Acnistus cauliflorus'' Schott
*''Acnistus cerasus'' Hieron. ex Seckt
*''Acnistus confertiflorus'' Miers [ This name is unresolved, but some data suggest that it is synonymous with Iochroma confertiflorum (Miers) Hunz. – but see also section below on closeness / hybridisation of genera ''Acnistus'' and ''Iochroma'' ].
*''Acnistus floccosus'' Werderm.
*''Acnistus floribundus'' (Kunth) G.Don
*''Acnistus geminifolius'' Dammer
*''Acnistus grandiflorus'' Miers
*''Acnistus guayaquilensis'' (Kunth) G.Don
*''Acnistus lehmannii'' Dammer
*''Acnistus macrophyllus'' (Benth.) Standl.
*''Acnistus miersii'' Dunal
*''Acnistus plumieri'' Miers
*''Acnistus pringlei'' Fernald
*''Acnistus punctatus'' Ridl.
*''Acnistus ramiflorus'' Miers
*''Acnistus sideroxyloides'' (Willd. ex Roem. & Schult.) G.Don
*''Acnistus virgatus'' Griseb.
*''Atropa arborea'' Willd. ex Dunal
*''Atropa arborescens'' L.
*''Atropa arborescens'' Roem. & Schult.
*''Atropa sideroxyloides'' Willd. ex Roem. & Schult.
*''Atropa solanacea'' All. ex Steud.
*''Brachistus oblongifolius'' Miers
*''Brachistus physocalycius'' D.A.Sm.
*''Brachistus riparius'' (Kunth) Miers
*''Capsicum oblongifolium'' (Miers) Kuntze
*''Cestrum campanulatum'' Lam.
*''Cestrum cauliflorum'' Jacq.
*''Cestrum cauliflorum'' Sieber ex Bercht. & C.Presl
*''Cestrum kohauti'' Bercht. & J.Presl
*''Cestrum macrostemon'' Sessé & Moç.
*''Dunalia arborescens'' (L.) Sleumer
*''Dunalia arborescens var. campanulata'' (Lam.) J.F.Macbr.
*''Dunalia campanulata'' (Lam.) J.F.Macbr.
*''Dunalia macrophylla'' (Benth.) Sleumer
*''Ephaiola odorata'' Raf.
*''Eplateia arborescens'' (L.) Raf.
*''Fregirardia riparia'' (Kunth) Dunal
*''Lycium aggregatum'' Ruiz & Pav.
*''Lycium arborescens'' (L.) Spreng.
*''Lycium grandifolium'' Willd. ex Roem. & Schult.
*''Lycium guayaquilense'' Kunth
*''Lycium macrophyllum'' Benth.
*''Lycium ovale'' Roem. & Schult.
*''Pederlea aggregata'' (Ruiz & Pav.) Raf.
*''Pederlea arborescens'' (L.) Raf.
*''Pederlea cestroides'' Raf.

Taxonomy

It is a member of the subtribe Iochrominae, which contains the following genera:
*''Dunalia'' Kunth
*'' Eriolarynx'' (Hunz.) Hunz.
*''Iochroma'' Benth.
*''Saracha'' Ruiz and Pav.
*''Vassobia'' Rusby

''Iochroma'' Benth. was the genus most closely related to the monotypic genus ''Acnistus'', differing by its induplicate corolla aestivation – with five conspicuous plaits lacking in ''Acnistus'', its (''Iochroma'') accrescent calyx (unchanged or only slightly accrescent in ''Acnistus'') and its (''Iochroma'') larger anthers (1.4 – 2.1 mm long in ''Acnistus'', but 2.8 – 4.7 mm long in ''Iochroma'').

Concerning the very close relationship of ''Iochroma'' with the monotypic genus ''Acnistus'', it is of the utmost importance to make intensive collections properly annotated in southern Ecuador and northern Peru; in this region native populations grow, with yellow-coloured corollas which appear to be intermediate between both genera. – Armando Hunziker (2001)

In Hunziker’s revision of ''Acnistus'',Hunziker, A. T. 1982. Estudios sobre Solanaceae XVII. Revisión sinóptica de Acnistus. ''Kurtziana'' 15: 81–102. he acknowledged that ''Acnistus'' has greatest affinity to the genus ''Iochroma''. The important differences he noted between them were the small flowers and anthers of ''Acnistus'', the calyx (accresent in ''Iochroma'' but not in ''Acnistus''), and the bud aestivation (induplicate in ''Iochroma'' but valvate in ''Acnistus''). Confusing this demarcation are a few species currently placed in ''Iochroma'' that have the latter two characteristics of ''Acnistus''. For example, ''Iochroma ellipticum'' and ''I. confertiflorum'', two large-flowered species that were transferred from ''Acnistus'' by Hunziker, have valvate bud aestivation and lack a strongly accresent calyx. This combination of traits is also found in two recently named species, ''I. edule'' and ''I. salpoanum'' and in ''I. peruvianum''. Furthermore, field observations of these five ''Iochroma'' spp. (S. D. Smith, personal observation) indicate that they share with ''Acnistus'' a conspicuous green mark on the inner surface of the corolla lobe, which fades to yellow as the flower ages. Thus, it is not surprising that ''Acnistus'' and these five other species form a well-supported clade in our analyses...but whether this group should be officially segregated from ''Iochroma'' deserves careful consideration...The small-flowered form traditionally named ''Acnistus arborescens'' occurs from Argentina to Mexico and the Caribbean and is morphologically variable...''A. arborescens'' ayrefer to a lowland progenitor form that has given rise to multiple novel higher-elevation forms... ''A. arborescens'' may occasionally hybridize in nature with related higher-elevation taxa such as ''Iochroma confertiflorum'' (S. D. Smith, personal observation)... – Stacey DeWitt Smith and David A.Baum (2006)De Witt, S. and Baum, David A. 2006. Phylogenetics of the Florally Diverse Andean Clade Iochrominae (Solanaceae) ''American Journal of Botany'' 93(8): 1140–1153.

Description

''I. arborescens'' forms a large shrub or small tree up to 10 meters in height. It flowers in clusters on naked branch parts below the leaves. Leaves are alternate, simple, elliptical, narrow to a long v-shape at the base, variably narrowed to a point at the tip, 15 to 30 cm long and 5 to 15 cm wide, margins entire or slightly wavy, hairless except when young. Young stems and young leaves have rusty hairs. The fragrant flowers bloom in clusters of 30 or more, with broadly funnel-shaped tubes about 1.2 cm long and recurving lobes. The protruding stamens are greenish-white to cream. The bright orange fruit is round, and about 1 cm across. There is evidence that these fruits are bird-dispersed.

The plant flowers sporadically throughout the year and fruits generally from March to July.

Distribution and habitat

The plant is native to Central and South America, and the Caribbean, a species characteristic of Montane cloud forests (in clearings, forest edges etc.) between 300 and 2000m elevation. In Puerto Rico and the United States Virgin Islands, it is classified by the US Department of Agriculture as a native plant species.

Edibility/inedibility of fruit

Some sources claim that the attractive fruits are edible (though causing diarrhea if consumed to excess) : others that they are inedible, due to bitterness or insipidity. The variability in chemistry of different populations (see below) may account for these conflicting accounts. In addition to being consumed raw, the fruits have also been used to prepare fruit preserves and / or jellies .

Medicinal uses

Leaf extracts in have been used in folk medicine for cancerous growths, and scientific studies indicate that compounds present in the plant display ''in vitro'' cytotoxic activity against a panel of human cancer cell lines. A hot infusion of the leaves or bark has been used for bruises and sprains.

Psychoactivity

In Brazil, the plant is considered to be psychoactive, possessing narcotic and depressant properties. The patois name ''Tabak djab'' (''Devil's tobacco'') may be significant in this context, suggesting that the leaves of the plant may have been smoked. Compare the Spanish name ''Tabaco del Diablo'' – also meaning ''Devil's Tobacco'' – applied to ''Lobelia tupa'', a narcotic plant smoked by the Mapuche of Chile.

Toxicity

''Acnistus arborescens'' is seldom portrayed in the literature as a particularly poisonous plant, but two sets of herbarium notes from dried specimens held by the New York Botanical Garden present a different picture : a specimen collected in Peru bears the note 'sap very poisonous' and gives the common name 'Catahui', while another collected in Martinique under the synonym ''Atropa arborescens'' carries the German note 'Die Pflanze enthält narkotisch giftige Stoffe' (the plant contains narcotic poisons).

Chemistry

The plant contains withanolides, including cytotoxic withaphysalins. An alkaloid, acnistine is also sometimes present, studies having indicated that this widespread tropical American species contains a number of chemical races, other analyses of the same species having yielded yet other compounds. Ayensu (1981) lists alkaloids, glycosides, organic acids, saponins and tannins as constituents of plant material collected in Trinidad and Dominica.

The essential oil from leaves harvested from a population of ''I. arborescens'' growing in the vicinity of Mérida, Venezuela, has been isolated by hydrodistillation. The chemical composition of the leaf oil thus recovered was determined by GC-FID and GC-MS and the most abundant components found to be (Z)-hex-2-enal (40.7%) and estragol (25.6%).

Influence of floral scent upon insect pollination

The flowers of ''I. arborescens'' secrete a fragrant compound of rare occurrence (though found also in roses and the flowers of the Amaryllid ''Narcissus tazetta'') called orcinol dimethyl ether or 3,5-Dimethoxytoluene. This volatile is almost undetectable by the human nose, but (as revealed by experiments) readily detectable by the olfactory sense of honey bees.

Cultivation

''I. arborescens'' is grown as an ornamental tree for gardens and natural landscaping projects for its attractive flowers and abundant beautiful golden fruit, the latter being relished by many species of birds – whence its Brazilian common name ''Fruta-de-sabiá''
(Portuguese for ' thrush fruit'). Frisch, Johan Dalgas & Frisch, Christian Dalgas, ''Aves Brasileiras e Plantas que as atraem'', São Paulo, 2004, Dalgas Ecotec, 3rd. edition, , page350

Gallery

File:Flore médicale des Antilles, ou, Traité des plantes usuelles (Pl. 177) (8182057733).jpg, Plate from ''Flore médicale des Antilles'' (1827) by J. Descourtilz, bearing the French title 'Nicotiana-leaved (i.e. Tobacco-leaved) belladonna' and showing anatomy of flower and fruit of ''Acnistus arborescens''.
File:Acnistus arborescens 2.jpg, ''Acnistus arborescens'', cultivated plant, Lankester Botanical Garden Costa Rica.

References

External links

USDA Plant profile: ''Acnistus arborescens'' (Hollowheart)
{{Taxonbar, from=Q4674438

Physaleae
Flora of Central America
Flora of the Caribbean
Flora of northern South America
Flora of Brazil
Flora of the Atlantic Forest
Flora of Puerto Rico
Flora of Southeastern Mexico
Bird food plants
Garden plants of Central America
Garden plants of South America
Ornamental trees
Plants described in 1756
Flora without expected TNC conservation status