Modern Phytomorphology 3: 39–44, 2013 FRUIT AND SEED DISCOVERIES IN STICHONEURON MEMBraNACEUM HOOK. F. (STEMONACEAE): AN ENDEMIC TO INDO-MYANMAR Koushik Majumdar & B.K. Datta Abstract. Stichoneuron membranaceum Hook. f. is an endemic species of Indo-Myanmar hotspot whose fruit and seed remained unknown to science since 1850, until they were collected from Tripura, Northeast India. Based on these gatherings, this study is the first report about the development and morphological features of fruit and seed. Earlier historical collections of this species were discussed. Its preferred habitat, possible pollinating agents and seed dispersal mechanism were also investigated. Key words: Stichoneuron membranaceum, morphology, fruit, seed, hermaphroditism Plant Taxonomy and Biodiversity Laboratory, Department of Botany, Tripura University Suryamaninagar, 799022 Tripura, India; [email protected] Introduction Deb 1983), Sylhet of Bangladesh (Barbhuiya & Gogoi 2010) and Northern Burma (Tanaka Stemonaceae is a very important et al. 2007; Inthachub et al. 2009). Whereas, monocotyledon family, since it is the only species S. bognerianum Duyfjes,S. calcicola source of the stemona alkaloids (Ye et al. Inthachub, S. caudatum Ridl. and S. halabalensis 1994; Pilli & Ferreira 2000). The extracts Inthachub are mainly distributed in Peninsular from tuberous roots of Stemonaceae are Thailand and Malesia Inthachub( et al. popular to be used as insecticides and several 2009). Fruit and seed formation and their other traditional medicines (Valkenburg & characteristics were well described for above Bunyapraphatsara 2002; Inthachub et al. mentioned four Peninsular-Malesian species; 2009). There are c. 3 genera Croomia( Torr., where fruit usually elongate, apex acute or Stemona Lour. and Stichoneuron Hook. f.) and beaked, seed broad-ellipsoid, longitudinally c. 25 species belonging to this family, mostly ridged, wide and hollow aril with a usually long distributed in Southeast Asia but spreading also funicle (Inthachub 2008; Inthachub et al. to tropical Australia and with even one species 2009). to Southeast United States (Duyfjes 1993). The botanical collection ofS. membranaceum There are 2 genera of the family was firstly made by J.D. Hooker probably Stemonaceae having 5 species in India viz. during 1850 from Khashi Hills of Meghalaya Stemona tuberosa Lour., S. minor Hook. f., and afterward several other collections were S. curtisii Hook. f., S. griffithiana Kurz and also done from Indo-Maynmar hotspot. In the Stichoneuron membranaceum Hook. f. (Hooker year 1941, R.N. De and K. Biswas collected 1892; Karthikeyan et al. 1989; Mabberley S. membranaceum from Shylet of Bangladesh 2008). Genus Stichoneuron comprises 5 and Jampui Hills of Tripura respectively. species, distributed from Northeast India to During 1952 Koelz collected this species from Thailand and Malay peninsula Heywood( Khasia Hills of Meghalaya where functionally 1978; Duyfjes 1992; Kubitzki 1998). S. male flowers were recorded. Subsequently its membranaceum distributed in Meghalaya and functional female flower was also collected by Tripura of Northeast India (Hooker 1892; D.B. Deb in the year 1962 from Chailengta of © The Author(s), 2013 3 (2013) had ever Stichoneuron 2007). Since then, no then, 2007). Since 2011), we collected its collected we 2011), 2009). However such data data such 2009). However et al. S. membranaceum et al. et al. et al. et al. aterial and methods and aterial M Tanaka S. membranaceum. Modern Phytomorphology In course of our floristic inventory in Tripura of our floristic in course inventory In Majumdar Inthachub ( Visam (24° 07’ 13.10” from flower male and N Tripura North E;amsl), 2351 ft alt. 92° 16’ 34.10” the functionally flower female recently most and Srirampur from fruits collected including were E; alt. – 351 ft 91° 46’ 00.7” N and (24° 07’ 33.10” semi-evergreen The Kamalpur of Tripura. amsl), of North observed in the Visam, were patches of Srirampur the vegetation whereas Tripura; by dominated was Hills range Atharamura in with mixeddeciduous trees bamboos. densely identify to able only the collect and were We North of Visam, in functionalflowers male did 2012. We June, 2010 and during May, Tripura any or flower hermaphroditic not observe any 2012 During February, of fruit area. trace in that were flowers hermaphroditic and both male Hills in Atharamura Srirampur from collected district. And during June, Tripura of West range fruit both mature collect to able were 2012 we Observations on area. Srirampur from seed and carried out directly were traits fruitsflower and living specimens on fresh in their natural were or measures also and counts habitats other specimen of specimen other its fruit that so this from region, collected been in the undescribed, still even seed and remained revision of the genus recent most ( its for understanding needed urgently were biology several and reproductive taxonomy, ecology. and of conservationaspects status summarized we communication present In of fruitsour observations on a sampling and In on the field. recognized veryseeds, recently discuss we addition, the possible pollinating preferred and dispersal mechanism seed agents, of habitat Tripura, North-east India; where he described where India; North-east Tripura, cells as shortanther diverging, and ovary half the from inferior with ovules hanging numerous et al. Murata gap, a long After of the locule. top this Northern in 2007 from species gathered was functionally where Burma flower male ( reported Table 1. An account of the historical collections of Stichoneuron membranaceum by different workers from Indo-Myanmar hotspot. Sl. Collection Collection Collectors Herbarium Distribution Flower Type Source No. number Year name Location Locality State Region Country 1 - 1850 J.D. Hooker ASSAM Khasia Hills Meghalaya Northeast India Female Hooker (1888) Barbhuiya and Gogoi 2 20284 1941 R. N. De ASSAM Ranpur plantation - Sylhet Bangladesh - (2010) 3 5073 1941 K. Biswas CAL Hmonpui, Jampui Hills Tripura Northeast India - Deb (1983) 4 5835 1952 Koelz ASSAM Cherrapunjee, Khasia Hills Meghalaya Northeast India Male Inthachub et al. (2009) 5 2689 1962? D.B. Deb CAL Chailengta Tripura Northeast India Female Deb (1983) 6 - 2007 Murata et al. MBK & TI Northern Burma - Northern Burma Male Tanaka et al. (2007) 7 1033 2010 K. Majumdar TUH Visam, North Tripura Tripura Northeast India Male / Female Present study 8 1192 2012 K. Majumdar TUH Srirampur, Kamalpur Tripura Northeast India Male / Female Present study 40 Majumdar K., Datta B.K. Fruit and seed discoveries in Stichoneuron membranaceum 41 done at the laboratory using Opta-Tech zoom flowers are either functionally female or male in microscope. Other ecological characters were S. bognerianum, S. caudatum and S. halabalensis documented in the field. The world history ofS. (Duyfjes 1993). The description and drawing membranaceum collections from Indo-Myanmar provided by Hooker involved a functionally hotspot are chronologically arranged in Tab. 1. female flower with patent reduced stamens, Corresponding herbarium sheets a larger ovary (c. 1.5 mm across) than in the (K. Majumdar 1033 and 1192) were deposited other known species and possibly two stigmas at TUH (Tripura University Herbarium). on the top of the conical style (Inthachub et al. 2009). But we recorded its ovary as only Results and discussion 0.33 -0.62 mm long × 0.47-0.56 mm diameter, which is very near the known range of ovary Male flowers (Fig. 1 c, e, f) c. 3.3 mm diameter i.e. c. 0.50 mm across recorded diam., pedicel 2.4-6.33 mm long; tepals 4, for other Stichoneuron species. However, its subtriangular, recurved, pale green, 0.95-1.55 functional male flower was also recorded much mm × 0.34-0.72 mm, hairy ( c. 0.11 mm) smaller than in all other Stichoneuron species outside; stamens 4, filament 0.81-0.92 mm (Tanaka et al. 2007); and these ones exhibit a long, dark purple papillose (c. 0.07 mm), anther less pronounced functionally male and female bright orange, 2 dorsifixed thecae, c. 0.34 mm × dimorphism, based on the small number of 0.31 mm. flowers seen Inthachub( et al. 2009). Thus, Hermaphrodite flowers (Fig. 1 d) c. 4.8 mm hermaphroditic flowers ofS. membranaceum diam., pedicel 11.46 -12.29 mm long; tepals have pedicel c. 10 mm long and corolla c. 4 mm 4, subtriangular, recurved, pale green, in diameter, whereas in male flower pedicel is 1.21-1.93 mm × 0.42-0.97 mm, glabrous 3-6 mm long and corolla c. 3 mm in diameter inside, hairy (c. 0.14 mm) outside; stamens 4, only. Dimorphic flowers could be recognized stout, filament base adnate to tepals, filaments in the field by bright orange dorsifixed thecae 0.75-0.86 mm long, violet-dark purple papillose, (2) on top of the filament in slightly smaller anther diverging into three small yellow thecae staminate (male) flower, while pale-yellow on the top of the filament, c. 0.26 mm long, thecae (3) separated on the top of the filament two white glands, dorsifixed.Ovary (Fig. 1 i) in pistillate (female) flower with addition of minute, green, smooth, ovoid, semi-inferior, two white glands. Nevertheless, Inthachub 0.33-0.62 mm × 0.47-0.56 mm, style absent, et al. (2009) also suggested that the flowers of stigma inconspicuous, ovule basal. S. membranaceum are protandrous with initially Fruits (Fig. 1 j, m, n) capsular, glabrous, forward directed protruding stamens with narrowly ovoid with 2-valved, 8.11-20.44 mm orange-yellow pollen and minute ovary, and × 4.20-7.19 mm, apex beaked 1.5-2 mm long, ovary possibly develops later when the stamens dark green (immature) to pale green (mature), with empty anthers are laterally pushed away. pedicel 5-10 mm long. Seeds (Fig. 1 o, p) 1-5, black, broadly The availability and sexual differences ellipsoid, 4.75-5.14 mm × 2.06-2.46 mm, sharp in population may be due to seasonal and longitudinal ridged; base surrounded by lobed microhabitat preferences; which are generally and white, hollow papery aril c.