Nypa Steck, Sagu : 15 (1757)

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Number of Taxa

  • 1 species

Discussion

  • In both vegetative and reproductive characters, Nypa differs markedly from other palms. The erect inflorescence (Uhl 1972a) bearing a terminal head of pistillate flowers and lateral spikes of staminate flowers is unique in the family. Similar sepals and petals in both staminate and pistillate flowers, lack of staminodes and pistillodes, an androecium of only three stamens with united filaments, and three separate carpels of unusual form are exceptional floral characters. The adaptability of the fruit for floating is also noteworthy.The pistillate head was once thought similar to those of phytelephantoid palms; early scholars (Drude 1887, Martius 1823–1850) classified Nypa with the phytelephantoid palms, but both the arrangement and the structure of the flowers are markedly different. The combination of solitary flowers, distinct and similar sepals and petals, free carpels of cupular form, a chromosome number of 17, the reduced stamen number and fusion of the filaments, the lack of staminodes and pistillodes and the adaptation of the fruit for floating occurs nowhere else in the family. The pistillate flowers appear to be structurally and developmentally unique within the family. Although the perianth encloses the carpels in early stages, by anthesis the carpels much exceed the perianth, members of which are displayed and obscured. The carpel is basally tubular with a mouth-like stigmatic opening and appears to represent a different, unspecialised form. (J. Dransfield, N. Uhl, C. Asmussen, W.J. Baker, M. Harley and C. Lewis. 2008)

Biology And Ecology

  • Nypa is strictly a mangrove palm, occurring in a variety of estuarine situations; it usually grows in soft mud, often in vast natural stands. Pollination appears to be by drosophilid flies in New Guinea (Essig 1973), but Hoppe (2005) suggests a combination of pollination by various different insects and possibly also wind; correlations of pollination with floral anatomy and development have been noted (Uhl and Moore 1977a). (J. Dransfield, N. Uhl, C. Asmussen, W.J. Baker, M. Harley and C. Lewis. 2008)

Etymology

Diagnosis

Description

  • Large, creeping, unarmed, pleonanthic, monoecious palm. Stem stout, prostrate or subterranean, branching dichotomously, curved leaf scars evident above, roots borne along the lower side. Leaves few, very large, erect, reduplicately pinnate; sheath soon splitting, glabrous; petiole stout, elongate, wide basally, channelled adaxially, terete distally, the base often persistent as a conical stub after the blade has disintegrated; rachis terete basally, becoming angled distally; leaflets numerous, single-fold, regularly arranged, acute, coriaceous, midrib prominent bearing distinctive, shining, chestnut-coloured, membranous ramenta abaxially, transverse veinlets not evident. Inflorescences solitary, interfoliar, erect, branching to 5(–6) orders, protogynous; peduncle terete; prophyll 2-keeled, tubular; peduncular bract tubular, somewhat inflated, pointed, rubbery, splitting longitudinally; rachis usually shorter than the peduncle, terete, terminating in a head of pistillate flowers and below this bearing 7–9 spirally arranged, closed, ± inflated, tubular bracts each subtending a first-order branch; first-order branches adnate ca. 1/2 their length above the subtending bracts, each bearing and enclosed by a tubular prophyll in bud; subsequent branches all bearing a complete, tubular, closed prophyll and ending in a short catkin-like rachilla, bearing densely crowded, spirally arranged, solitary staminate flowers, each subtended by a small bract. Staminate flowers sessile; sepals 3, distinct, narrow, oblanceolate; petals 3, distinct, slightly imbricate, similar to the sepals but slightly larger, both loosely closed over the stamens in bud; stamens 3, filaments and connectives connate in a solid stalk, anthers elongate, extrorse; pistillode lacking. Pollen spheroidal, bi-laterally symmetric; aperture a meridional zonasulcus; ectexine semi-tectate, finely reticulate with wide-based supratectal spines; infratectum columellate; diameter 37–80 µm; post-meiotic tetrads tetragonal [1/1]. Pistillate flowers very different from the staminate; sepals 3, distinct, irregularly oblanceolate, petals 3, similar to those of the staminate flower; staminodes lacking; carpels 3(–4), distinct, much longer than and obscuring the perianth at maturity, ± obovoid, asymmetrical, angled by mutual pressure, ± acute distally, and with a ± lateral, funnel-shaped stigmatic opening, ovule anatropous, attached dorsally or submarginally near the base of the locule. Fruit borne in ± globose head, fertile and partially developed fruits intermixed, 1–3 carpels per flower maturing a seed; fruit developing from 1 carpel, compressed and irregularly angled, stigmatic remains terminal, pyramidal; epicarp smooth, mesocarp fibrous, endocarp thick, composed of interwoven fibrous strands, with an adaxial internal longitudinal ridge intruded into the seed. Seed broadly ovoid, grooved adaxially, hilum basal, raphe branches ascending from the base, endosperm homogeneous or rarely ruminate, with a central hollow; embryo basal. Germination on the fruiting head with the plumule exserted and pushing the fruit away; eophyll bifid or with several leaflets. Cytology: 2n = 34. (J. Dransfield, N. Uhl, C. Asmussen, W.J. Baker, M. Harley and C. Lewis. 2008)

Anatomy

Relationships

Fossil record

  • The fossil record for Nypa is outstanding among palms (see for example, Gee 1990). Most of the records are of fruits (e.g., Bowerbank 1840, Rendle 1894, Tralau 1964) or pollen (e.g., Muller 1968, 1979, 1981, Morley 2000), although occasionally leaf (Chandler 1961a, Pole and McPhail 1996, Mehrotra et al. 2003), flowering parts (e.g., Chandler 1961c), leaf epidermis (e.g., Kulkarni and Phadtare 1980) or root (e.g., Verma 1974) material is reported. Furthermore, the fossils are globally distributed through tropic and temperate zones until the global climatic deterioration at the end of the Middle Miocene. Records of possible affinity with Nypa for pinnate palm leaves are rare. From the Middle Eocene Bournemouth Freshwater Beds, Gardner (1882) recovered an abundance of pinnate palm leaves, which he considered to resemble Iriartea more than any other genus. However, later in a Guide to Fossil Plants in the British Museum (Natural History) it was written of one large specimen that, “it might possibly belong to Nypa whose fruits have been found at Bournemouth.” (see Chandler 1963 p. 7). Occasionally pinnate leaves have been found in close association with other fossil Nypa organs, suggesting that they could be Nypa leaves (Pole and McPhail 1996, Mehrotra et al. 2003). Leaf cuticle considered to be from Nypa has been found in close association with Spinizonocolpites in the Ratnagiri lignite Beds in India (Kulkarni and Phadtare 1980, 1981). The earliest records for fossil fruits and seeds (Nypa, Nipadites, Nipa) seem to be those of Gregor and Hagn (1982) recovered from the earliest Palaeocene (Danian) of Egypt (Bir Abu Munqar Formation) and of Dolianiti (1955) for the Palaeocene of Brazil or, possibly, the remarkably early Lower Cretaceous (Aptian) record of Jahnichen (1990; see comments in Chapter 5: The Fossil Record of Palms). Fossil fruits are also recorded from the Lower Eocene of southeastern North America (e.g., Berry 1914c, 1916b), and Middle Eocene (Claibornian) of Texas (Arnold 1952); from the Eocene of Europe — Belgium, France, The Netherlands, Italy, Hungary (see Tralau 1964), and the Lower Eocene London Clay Flora (e.g., Bowerbank 1840, Chandler 1961b). They are also present in the Upper Eocene of Russia (Kryshtofovich 1927). On the African continent, fruits are known from the Eocene of Egypt (Bonnet 1904, Kräusel 1939) and of Senegal (Fritel 1921). From the Eocene of Borneo, Kräusel (1923) described a fossil fruit, Nipadites borneensis. Nypa fruits are also recorded from the Upper Cretaceous in India (Deccan Intertrappean — although the age span of these volcanic deposits is controversial, see Chapter 5: The Fossil Record of Palms) and these records are summarised by Singh (1999). The earliest records of Spinizonocolpites (see Muller 1981 and Gee 1990 for summaries and authorship) are from the Maastrichtian, and occur almost simultaneously in South America (Colombia, Brazil and Venezuela), Africa (Ivory Coast, Senegal and Cameroon), India and Malesia (Borneo; Muller 1968, although there is some doubt about the age of this record, Morley 1998). Other Upper Cretaceous records not reviewed by Muller (1981) or Gee (1990) include those from Somalia (Schrank 1994) and India (Singh 1999). From the Palaeocene until the Middle Miocene, Spinizonocolpites is also recovered from deposits in current temperate zones, as well as from those of the tropics and subtropics (see Gee 1990, 2001) — USA (Gulf Coast), Europe (southern England, Belgium, France, Spain, Germany and Hungary), Russia, Africa (Senegal, Morocco and Egypt), India, Australia and New Zealand. The Indian record is extensive (see Singh 1999) although a proportion of the spinose pollen described and illustrated needs further re-appraisal. Further records include those from Colombia (Jaramillo and Dilcher 2001), southern England (Harley et al. 1991), France and Belgium (Paris and Belgian Basins; Schuler et al. 1992), Austria (Hofmann and Zetter 2001, Zetter and Hofmann 2001), Hungary (Ràkosi 1976), Nigeria (Jan du Chêne et al. 1978, Babajide Salami 1985), Pakistan (Frederiksen 1994), China (Song et al. 1999) and Tasmania (Pole and McPhail 1996). Rarely pollen, fruits or other fossil Nypa ‘organs’ are found in close association (e.g., Kulkarni and Phadtare [1980, 1981], Pole and McPhail [1996], Mehrotra et al. [2003]). (J. Dransfield, N. Uhl, C. Asmussen, W.J. Baker, M. Harley and C. Lewis. 2008)

Uses

  • Nypa fruticans is ethnobotanically very important. The leaves are one of the most important sources for the production of palm shingles (‘atap’) for thatching, and also have minor uses such as for cigarette papers and fishing floats. The inflorescences are tapped for sap for sugar and alcohol production. The large natural stands of Nypa remain a greatly underexploited resource for fuel alcohol. The young endosperm is eaten, usually boiled in syrup, as a sweetmeat. The great but passive potential of Nypa as a stabiliser of estuarine mud in preventing coastal erosion should not be underestimated. For details of the utilisation of Nypa, see Burkill (1966), Brown and Merrill (1919) and Fong (1987, 1989). (J. Dransfield, N. Uhl, C. Asmussen, W.J. Baker, M. Harley and C. Lewis. 2008)

Bibliography

  • Dransfield, J. , Uhl, N. , Asmussen, C. , Baker, W.J. , Harley, M. & Lewis, C. 2008. Genera Palmarum. The evolution and classification of palms. Kew Publishing, Royal Botanic Gardens Kew.