Artocarpus subg. Artocarpus
Description
Leaves spirally arranged;
stipules fully amplexicaul, usually longer than 1 cm.
Flowers often intermixed with peltate to spathulate (in pistillate inflorescences often (partly) caducous) bracts, or in staminate inflorescences with rod-shaped interfloral processes, and in pistillate inflorescences with conical, subulate or filiform processes, or else bracts and processes absent.
Distribution
Asia-Tropical: New Guinea endemic; Sri Lanka (Sri Lanka endemic), Asian mainland present, Solomon Islands present, Western New Guinea present, eastern Malesian, extending into Micronesia, Melanesia, and Polynesia present, western Indian Peninsula present, western part of the Malesian region present
This subgenus is concentrated in the western part of the Malesian region with 19 indigenous species, some species extending to the Asian mainland and some species to western New Guinea. Artocarpus altilis is clearly eastern Malesian, extending into Micronesia, Melanesia, and Polynesia, mainly with cultivars. Artocarpus sepicanus is endemic to New Guinea and A. teijsmannii extends with its subsp. subglabrus to the Solomon Islands.
Artocarpus nobilis Thwaites is endemic to Sri Lanka. The origin of A. heterophyllus lies probably in the western Indian Peninsula. Clear morphological connections of A. hirsutus with material from the Sino-Himalayan region (as indicated below under A. hispidus, see p. 93) makes it uncertain whether A. hirsutus is a distinct species and another endemic of the Indian Peninsula.
Artocarpus nobilis Thwaites is endemic to Sri Lanka. The origin of A. heterophyllus lies probably in the western Indian Peninsula. Clear morphological connections of A. hirsutus with material from the Sino-Himalayan region (as indicated below under A. hispidus, see p. 93) makes it uncertain whether A. hirsutus is a distinct species and another endemic of the Indian Peninsula.
Morphology
— In staminate inflorescences, the bracts are basically peltate (to spathulate), but may be modified into rod-shaped ‘processes’, which were described by Jarrett as sterile flowers.
In pistillate inflorescences lacking (sub)peltate bracts, the flowers are often intermixed with rigid ‘processes’ varying in shape and length from conical to filiform, and from straight to ± curved. These are apparently also modified bracts. These ‘processes’ often resemble the hardened free apices of the perianths which vary from cushion shaped to pyramidate to conical to spine-like to subulate to filiform (and straight to curved). The perianth apices can be distinguished from ‘processes’ by the perforate apex or also by the persisting stigmata. The variation of the apices of perianths and the interfloral ‘processes’ is illustrated in Fig. 16.
In pistillate inflorescences lacking (sub)peltate bracts, the flowers are often intermixed with rigid ‘processes’ varying in shape and length from conical to filiform, and from straight to ± curved. These are apparently also modified bracts. These ‘processes’ often resemble the hardened free apices of the perianths which vary from cushion shaped to pyramidate to conical to spine-like to subulate to filiform (and straight to curved). The perianth apices can be distinguished from ‘processes’ by the perforate apex or also by the persisting stigmata. The variation of the apices of perianths and the interfloral ‘processes’ is illustrated in Fig. 16.
Taxonomy
A group of species included by Jarrett (1959) in sect. Duricarpus is characterised by globose (to ellipsoid) infructescences with indurated apices ranging from cushion shaped to (up to 1 cm long) cylindrical to spine-like to clavate (persistent or caducous) peltate interfloral bracts, terminal styles and longitudinally aligned embryos with equal cotyledons. This group comprises A. anisophyllus, A. annulatus, A. asperula Gagnep. (Indochina), A. brevipedunculatus, A. calophylla Kurz (Myanmar), A. chama Buch.-Ham. (Sikkim to Vietnam), A. hirsutus Lam. (India), A. hispidus, A. lanceifolius, A. nobilis Thwaites (Sri Lanka), A. odoratisssimus, A. rigidus, and A. sarawakensis (but see p. 93). Artocarpus hirsutus deviates in the pendulous spicate staminate inflorescences and in the absence of peltate interfloral bracts.
A second main group (section) comprises species included in sect. Artocarpus which is characterised by the frequent absence of peltate interfloral bracts, being substituted by elongate processes, or totally absent. The apices of the perianths varies from cushion shaped to spine-like. The style is lateral to subbasal. The embryos are obliquely aligned with unequal to equal cotyledons. The group can be subdivided into four subgroups:
A second main group (section) comprises species included in sect. Artocarpus which is characterised by the frequent absence of peltate interfloral bracts, being substituted by elongate processes, or totally absent. The apices of the perianths varies from cushion shaped to spine-like. The style is lateral to subbasal. The embryos are obliquely aligned with unequal to equal cotyledons. The group can be subdivided into four subgroups:
- Plants with cauliflorous species: A. heterophyllus and A. integer.
- Plants usually with incised laminas in the adult state: A. altilis and possibly also A. treculianus in which the lamina is sometimes pinnately incised in the adult state. The latter species also shows affinities to A. teijsmannii.
- Plants with entire laminas in the adult state, the staminate inflorescences with smooth surfaces and the vegetative parts inconspicuously whitish (to brownish) hairy or glabrous: A. excelsus, A. lowii, A. sepicanus, and A. teijsmannii.
- Plants with entire laminas in the adult state, the staminate inflorescences with sulcate to tuberculate surfaces and the vegetative parts more or less conspicuously brown hairy: A. elasticus, A. kemando, A. sericicarpus, and A. tamaran.