Artocarpus
Description
Trees, monoecious.
— The trees of several species can become very tall and the trunks then often have buttresses. The leafy twigs are slender (leptocladous) to thick (pachycladous), the latter type in combination with large leaves and infructescences that can become large as in A. altilis. Two species with more or less large infructescences, A. heterophyllus and A. integer, are leptocladous but cauliflorous, with the inflorescences in short branchlets on the trunk or main branches. Most species are evergreen and show continuous growth. In subg. Pseudojaca some species have intermittent growth, as described below (p. 108).
Leaves spirally arranged (subg. Artocarpus) or distichous (subg. Pseudojaca); — They are spirally arranged in subg. Artocarpus and distichous in subsp. Pseudojaca. At germination the first leaves may be opposite or they may be reduced to scale-leaves. In the juvenile state the lamina is pinnately lobed to more deeply incised. In some species (of subg. Artocarpus) the lamina is (also) incised in the adult state, in A. anisophyllus usually down to the midrib and the segments petiolulate, thus the lamina being seemingly compound.
The two subgenera do not only differ in the arrangement of the leaves but also in the presence of glandular spots or glands on the lamina as described below for subg. Pseudojaca (see p. 108), and in features of the stipules.
stipules free, amplexicaul (subg. Artocarpus) or lateral (subg. Pseudojaca). — The stipules are free and in subg. Artocarpus fully amplexicaul and relatively large, longer than 1 cm, up to 25(-35) cm in A. altilis. In subg. Pseudojaca, the stipules are lateral and short, mostly 0.2-0.5 cm long, or if subpersistent on opening shoots, then sometimes up to 1 cm long; in species with intermittent growth they may be subpersistent, forming terminal buds.
Inflorescences unisexual, solitary or in pairs in the leaf axils or on short-shoots on the older wood, pedunculate (or subsessile), bracteate or ebracteate. — Usually solitary and axillary, but in particular staminate inflorescences occur on short-shoots on the older wood (ramiflorous) in some species of subg. Pseudojaca. Cauliflory is found in subg. Artocarpus.
The flower-bearing parts vary from spikes to clavate spadices or narrowly ellipsoid to ellipsoid or globose heads; considerable variation can be found in the same species. The flowers are densely set and free in the staminate inflorescences and (partly) fused in the pistillate ones. The flowers are intermixed with bracts.
flowers numerous, free; stamen 1. ovary free, stigma 1 or 2 of equal or unequal length. fruit free, with a chartaceous to coriaceous to crustaceous pericarp or endocarp; — Ellipsoid (to globose), with a ± crustaceous to cartilaginous pericarp or endocarp varying in size, being either (0.6-)0.8-1.2(-1.5) or c. 2-3 cm long. Large seeds are associated with the cultivated form of the species.
seed without endosperm, embryo straight, longitudinally to obliquely aligned, cotyledons equal or unequal, radicle minute. — They are longitudinally aligned and with equal cotyledons in the groups with terminal styles and oblique and with unequal cotyledons in the groups in which the style becomes lateral to subbasal.
Leaves spirally arranged (subg. Artocarpus) or distichous (subg. Pseudojaca); — They are spirally arranged in subg. Artocarpus and distichous in subsp. Pseudojaca. At germination the first leaves may be opposite or they may be reduced to scale-leaves. In the juvenile state the lamina is pinnately lobed to more deeply incised. In some species (of subg. Artocarpus) the lamina is (also) incised in the adult state, in A. anisophyllus usually down to the midrib and the segments petiolulate, thus the lamina being seemingly compound.
The two subgenera do not only differ in the arrangement of the leaves but also in the presence of glandular spots or glands on the lamina as described below for subg. Pseudojaca (see p. 108), and in features of the stipules.
stipules free, amplexicaul (subg. Artocarpus) or lateral (subg. Pseudojaca). — The stipules are free and in subg. Artocarpus fully amplexicaul and relatively large, longer than 1 cm, up to 25(-35) cm in A. altilis. In subg. Pseudojaca, the stipules are lateral and short, mostly 0.2-0.5 cm long, or if subpersistent on opening shoots, then sometimes up to 1 cm long; in species with intermittent growth they may be subpersistent, forming terminal buds.
Inflorescences unisexual, solitary or in pairs in the leaf axils or on short-shoots on the older wood, pedunculate (or subsessile), bracteate or ebracteate. — Usually solitary and axillary, but in particular staminate inflorescences occur on short-shoots on the older wood (ramiflorous) in some species of subg. Pseudojaca. Cauliflory is found in subg. Artocarpus.
The flower-bearing parts vary from spikes to clavate spadices or narrowly ellipsoid to ellipsoid or globose heads; considerable variation can be found in the same species. The flowers are densely set and free in the staminate inflorescences and (partly) fused in the pistillate ones. The flowers are intermixed with bracts.
flowers numerous, free; stamen 1. ovary free, stigma 1 or 2 of equal or unequal length. fruit free, with a chartaceous to coriaceous to crustaceous pericarp or endocarp; — Ellipsoid (to globose), with a ± crustaceous to cartilaginous pericarp or endocarp varying in size, being either (0.6-)0.8-1.2(-1.5) or c. 2-3 cm long. Large seeds are associated with the cultivated form of the species.
seed without endosperm, embryo straight, longitudinally to obliquely aligned, cotyledons equal or unequal, radicle minute. — They are longitudinally aligned and with equal cotyledons in the groups with terminal styles and oblique and with unequal cotyledons in the groups in which the style becomes lateral to subbasal.
Distribution
The genus comprises c. 45 species and ranges from Sri Lanka to South China and through Malesia to the Solomon Islands and Australia; 32 of these species occur as wild trees in Malesia, A. heterophyllus only as cultivated species. These species are elements of forest in ever wet climates or where there is a short dry season, mostly below 1000 m. Some species can be found at altitudes up to 1500 or to 1800 m, and in New Guinea up to 2000 m.
The number of species of the genus represented in the Sino-Himalayan region is uncertain (see p. 94 and p. 107). At most three species, including A. heterophyllus, are endemic to the western part of the Indian Peninsula and Sri Lanka. Three species (if not also the wild form of A. altilis) extend through New Guinea to the Solomon Islands. The only species found in Australia is the widespread A. glaucus.
The number of species of the genus represented in the Sino-Himalayan region is uncertain (see p. 94 and p. 107). At most three species, including A. heterophyllus, are endemic to the western part of the Indian Peninsula and Sri Lanka. Three species (if not also the wild form of A. altilis) extend through New Guinea to the Solomon Islands. The only species found in Australia is the widespread A. glaucus.
Dispersal
Seeds are mainly dispersed by various arboreal animals such as monkeys, squirrels, and civet cats. Monkeys and squirrels bite the infructescence into pieces and carry off the seeds. Yellow, red, or purple infructescences are also eaten by birds. The large infructescences of the cauliflorous species, A. integer and A. heterophyllus, particularly in the latter species which can reach considerable dimensions, are probably dispersed by forest ungulates including elephants (Ridley 1930).
A. The dispersal of plants throughout the world
Taxonomy
The genus comprises two markedly distinct subgenera: Artocarpus and Pseudojaca. The differences are such that these two entities and Parartocarpus could be considered as equivalent at the subgeneric rank. The latter is distinct in the basally attached bracts, larger than those usually found in the two subgenera, and differs from subg. Artocarpus in the small connate stipules, and from subg. Pseudojaca in the intrapetiolar position of the connate stipules. Prainea is also very close to Artocarpus, differing in the free pistillate flowers.
For the complex taxonomic history of the genus, in particular with regard to species in cultivation and the confusion concerning the names of these species see , and for an account on the nomenclatural problems related to Artocarpus integer see .
G. Corner, E.J.H. 1938: Notes on the systematy and distribution of Malayan phanerogams, II. – The jack and the chempedak. Gard. Bull. Singapore 10, H. Corner, E.J.H. 1940: Wayside Trees of Malaya ed. – 1, 1, I. Corner, E.J.H. 1988: Wayside Trees of Malaya. – undefined journal – 1, J. Jarrett, F.M. 1959: Studies in Artocarpus and allied genera, III. – J. Arnold Arbor. 40, K. Van der Pijl, L. 1953: On the flower biology of some plants from Java - with general remarks on fly-traps (species of Annona, Artocarpus, Typhonium, Gnetum, Arisaema and Abroma). – Ann. Bogor. 1
Cytology
A chromosome number of 2n = 56 has been reported for the species (Fedorov 1969; Chen 1993; Oginuma & Tobe 1995), but the seedless (= sterile) variety of A. altilis is hexaploid and has 2n = 84 chromosomes (see Ragone 2001).
L. Chen., R.-Y (ed.) 1993: Chromosome atlas of Chinese fruit trees and their close wild relatives. – In: Chromosome atlas of Chinese principal economic plants, M. Chromosome numbers of flowering plants, N. Oginuma, K. & H. Tobe 1995: Karyomorphology of some Moraceae and Cecropiaceae (Urticales). – J. Pl. Res. 108, O. Ragone, D. 2001: Chromosome numbers and pollen stainability of three species of Pacific island breadfruit (Artocarpus, Moraceae). – Amer. J. Bot. 88
Uses
The genus includes two commonly cultivated trees as fruit trees throughout the tropics: A. altilis (Breadfruit) and A. heterophyllus (Jack or Jackfruit); A. integer (Chempedak) is widely grown in Malesia and A. odoratissimus (Marang) is in cultivation in the Philippines and Borneo (see for these species ). The infructescences of several other species, not in cultivation, are harvested for the juicy perianth parts and/or the seeds which are often eaten roasted (see Seibert & Jansen 1991).
The lightweight hardwood of several Artocarpus species is used for several purposes such as for construction, veneer, and various utensils (see Djarwaningsih et al. 1995). Several Artocarpus species also produce exudates such as latex (see Boer & Ella 2000) to use as birdlime or as medicine or stimulants (see Van der Vossen & Wessel 2000) and/or (bark) fibres to make cloth (see Brink & Escobin 2003).
P. Dela Cruz, F.S., Artocarpus odoratissimus 1991: Edible fruits and nuts. – In: Plant resources of South-east Asia, Q. Plant resources of South-east Asia
The lightweight hardwood of several Artocarpus species is used for several purposes such as for construction, veneer, and various utensils (see Djarwaningsih et al. 1995). Several Artocarpus species also produce exudates such as latex (see Boer & Ella 2000) to use as birdlime or as medicine or stimulants (see Van der Vossen & Wessel 2000) and/or (bark) fibres to make cloth (see Brink & Escobin 2003).
Citation
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Blanco 1879 – In: Fl. Filip., ed. 3: 73
Kochummen 2000 – In: Tree Fl. Sabah & Sarawak: 187
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F.M. Jarrett 1975 – In: Blumea: 409
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F.M. Jarrett 1959 – In: J. Arnold Arbor. 40: 113
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Roxb. 1832: Fl. Ind., ed. Carey 3: 521
Benth. & Hook.f. 1880 – In: Gen. Pl.: 376
L.f. 1781: Suppl.: 61, 411
Gaertn. 1788: p. 344. – In: Fruct. Sem. Pl.: t. 71, 72
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Backer & Bakh.f. 1965 – In: Fl. Java: 18