''Bactris'' is a genus of spiny
palms which are native to Mexico, South and Central America and the Caribbean. Most species are small trees about tall, but some are large trees while others are shrubs with subterranean stems. They have simple or
pinnate
Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and in ...
ly compound leaves and yellow, orange, red or purple-black fruit. The genus is most closely related to several other spiny palms—''
Acrocomia
''Acrocomia'' is a genus of palms which is native to the Neotropics, ranging from Mexico in the north, through Central America and the Caribbean, and through South America south to Argentina.
Description
''Acrocomia'' is a genus of spiny, pin ...
'', ''
Aiphanes
''Aiphanes'' is a genus of spiny palms which is native to tropical regions of South and Central America and the Caribbean.Kew World Checklist of Selected Plant Families There are about 26 species in the genus (see below), ranging in size fr ...
'', ''
Astrocaryum
''Astrocaryum'' is a genus of about 36 to 40 species of palms native to Central and South America and Trinidad.
Description
''Astrocaryum'' is a genus of spiny palms with pinnately compound leaves–rows of leaflets emerge on either side of th ...
'' and ''
Desmoncus
''Desmoncus'' is a genus of mostly climbing, spiny palms native to the Neotropics. The genus extends from Mexico in the north to Brazil and Bolivia in the south, with two species present in the southeastern Caribbean (Trinidad and the Windwar ...
''. The fruit of several species is edible, most notably ''
B. gasipaes'', while others are used
medicinally or for construction.
The ancestors of the genus are believed to have entered South America during the late
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...
. ''Bactris'' shows high rates of speciation.
Description
Both stems and leaves of ''Bactris'' species are generally covered with
spines. Stems generally bear spines on the internodes; in ''
B. glaucescens'' and ''
B. setulosa'' spines are also present on the nodes. A few species lack spines on their stems. All species have spiny leaves; the spines are often clustered on the
petiole or
rachis
In biology, a rachis (from the grc, ῥάχις [], "backbone, spine") is a main axis or "shaft".
In zoology and microbiology
In vertebrates, ''rachis'' can refer to the series of articulated vertebrae, which encase the spinal cord. In this c ...
. In some species the spines are only found on the tips of the leaflets.
Most species grow in multi-stemmed clumps with stems about tall and in diameter, but they span a range of sizes from tall trees to shrubs with subterranean stems and are sometimes single-stemmed. Stems can be as narrow as in ''
B.aubletiana'' or as broad as in ''
B. gasipaes''.
The leaves can be either
pinnate
Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and in ...
ly compound or simple; in some species like ''
B. hirta'' both types of leaves exist. Petioles range from to over in length, while the rachis (which bears the leaflets) can be to over long.
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...
s are borne singly emerging from the leaf
axil
A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, st ...
. Flowers grow in triplets along the inflorescence; each female flower is flanked by two male flowers; elsewhere along the inflorescence male flowers grow singly or in pairs. Ripe fruit can be yellow, orange, red or purple-black (other colours are present in a few species) and range from long.
Taxonomy
''Bactris'' is placed in the
subfamily
In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...
Arecoideae, the
tribe
The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English language, English is in the discipline of anthropology. This definition is contested, in p ...
Cocoseae
Cocoseae is a tribe of cocosoid palms of the family Arecaceae.
Description
The fruit of the Cocoseae is a modified drupe, with a sclerenchymatous epicarp and a highly developed mesocarp, formed mainly by parenchyma . The endocarp is generally s ...
and the subtribe
Bactridinae, together with the genera ''Acrocomia'', ''Aiphanes'', ''Astrocaryum'' and ''Desmoncus''.
Phylogenetic studies support the
monophyly
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic grou ...
of both the subtribe Bactridinae and the genus ''Bactris'', but differ in terms of how the genera within the subtribe are related to one-another.
The first species were attributed to the genus by
Nikolaus Joseph von Jacquin
Nikolaus Joseph Freiherr von Jacquin (16 February 172726 October 1817) was a scientist who studied medicine, chemistry and botany.
Biography
Born in Leiden in the Netherlands, he studied medicine at Leiden University, then moved first to P ...
in 1763, but a formal description of the genus was only published in 1777 by
Giovanni Antonio Scopoli
Giovanni Antonio Scopoli (sometimes Latinisation of names, Latinized as Johannes Antonius Scopolius) (3 June 1723 – 8 May 1788) was an Italian physician and natural history, naturalist. His biographer Otto Guglia named him the "first anational ...
. Later workers split ''Bactris'' into several genera (''Guilielma'', ''Augustinea'', ''Pyrenoglyphis'', ''Amylocarpus'' and ''Yuyba'') and described several hundred species.
Although earlier authors recognised between 239 and 257 species of ''Bactris'',
Andrew Henderson accepted 73 species and a single genus in his 2000 monograph,
while as of 2013
The Plant List included 79 accepted species.
Henderson recognised six informal groups within the genus, but used them only for convenience and did not consider them monophyletic groups. These groups were (1) the ''Amylocarpus'' group, (2) the ''Guilielma'' group, (3) the Orange-fruited group, (4) the ''Piranga'' group, (5) the Purple-fruited group, and (6) the ''Pyrenoglyphis'' group.
In their study of the Bactridinae, Wolf Eiserhardt and colleagues sampled 13 species of ''Bactris'' distributed among these six groups; five of these groups were represented by more than one species in their sample. Of these five, only the ''Guilielma'' group was potentially monophyletic (although support for this conclusion was weak). The other four were found to be either
polyphyletic
A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of conver ...
or
paraphyletic
In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...
(although here again, support was only strong for two of the four). The sixth group, the Orange-fruited group, was only represented by a single species in their data set.
; Species:
Evolutionary history
The subfamily Arecoideae is believed to have evolved in North America about 78 million years ago,
and colonised South America during the late
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...
before going extinct in North America.
The subtribe Bactridinae evolved between 54 and 35 million years ago,
The ancestors of ''Bactris'' diverged from those of ''Astroacryum'' between 26 and 36 million years ago.
In an analysis of the palm family, it was found that ''Bactris'' was one of six palm genera that showed the highest rates of speciation.
Distribution
The genus ranges from Mexico, through Central America and the Caribbean and across much of tropical South America. Diversity is highest in the Amazonian region. Most of the species in the Brazilian
Atlantic Forest
The Atlantic Forest ( pt, Mata Atlântica) is a South American forest that extends along the Atlantic coast of Brazil from Rio Grande do Norte state in the northeast to Rio Grande do Sul state in the south and inland as far as Paraguay and th ...
are
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...
to the region. Three species (''
B. cubensis'', ''
B. jamaicana'' and ''
B. plumeriana'') are
restricted to the Caribbean and form a closely related clade.
Uses
''Bactris gasipaes'', the peyibaye or peach palm, was domesticated in pre-Columbian times and is cultivated for its starchy fruit and
palm heart throughout the Neotropics, especially in Brazil, Colombia, Peru and Costa Rica.
Other species used for food include ''
B. brongniartii'', ''
B. campestris'', ''
B. concinna'' and ''
B. major''. ''
Bactris acanthophora'' and ''B. campestris'' are used medicinally, while ''
B. barronis'', ''
B. pilosa'' and ''
B. setulosa'' are used in construction.
References
{{Taxonbar, from=Q135451
Arecaceae genera
Neotropical realm flora