Founded in 1991 and published by the Indian Association for Angiosperm Taxonomy (IAAT), Rheedea is an international peer-reviewed journal with four online and two print issues per year. The online issues will be published in March, June, September and December while the printed issues will be published in June and December. Rheedea is a peer-reviewed journal named after the renowned Dutch botanist Hendrik van Rheede, known for his seminal work Hortus Malabaricus. ISSN: 2582-2438 (Online edition) ISSN: 0971-2313 (Print edition)
Journal of the Indian Association for Angiosperm Taxonomy
Studies on Reproductive aspects of Willisia selaginoides (Podostemaceae), an endemic species from Kerala
Section: Articles Keywords: Endemic, germination, Podostemoideae, self-pollination, thallus The present study deals with some aspects of reproductive biology of an endemic and endangered aquatic angiosperm, Willisia selaginoides (Bedd.) Warm. ex Willis (Podostemaceae) restricted to the Western Ghats of India. Due to its occurrence in the challenging habitats, there is limited information available on its reproductive biology. Willisia possesses a small tuft of shoots with triangular thick scales and terminal flowers. The horizontal thallus arising after seed germination is considered as primary shoot and the vertical shoots arising on the dorsal surface of the thallus are considered as secondary shoots. The gummy substance exudes from the lower elongated surface cells (rhizoids) of the shoots and holdfast help in firm attachment to the shoots to rocks in fast flowing water. The flower is enclosed in spathella and represented by a pistil with bilobed stigma and a pair of dithecous anthers. Initiation of flower buds and subsequent development occurs in submerged conditions but flowers open only after the water level lowers down after monsoon. Pollination occurs when the flowers are just exposed to air after lowering of water level at the air-water interface. Co-occurrence of stigma receptivity with anther dehiscence and the close proximity of two organs seem to promote self -pollination. The pollen:ovule ratio (32:1) and ovule:seed ratio (6:5) suggest that even after relatively low pollen:ovule ratio, chances of high seed set occur. It clearly indicates the best possibility of selfpollination.
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Evolution of macro and micromorphology of Eriocaulon (Eriocaulaceae) and its relation with the aquatic environment
Section: Articles Keywords: Poales, Pipeworts, Taxonomy, Anatomy, Aquatic habitat, Evolution Eriocaulon L. is a pantropical genus comprising approximately 495 species. Previous taxonomic studies have proposed infrageneric classifications based on selected morphological characters; however, molecular phylogenetic analyses have shown that most of these classifications are paraphyletic. A recent multivariate analysis of anatomical data identified two major groups within the genus: one composed of amphibious species and the other of aquatic species. In this context, the present study aims to test the hypothesis that these groups correspond to distinct evolutionary clades by conducting a cladistic analysis of Eriocaulon based on morphological data. Our analysis included 65 species of Eriocaulon and seven outgroup species, using a dataset of 89 macro- and micromorphological characters. Parsimony analyses conducted in TNT recovered 24 equally parsimonious trees. In all analyses, Eriocaulon was resolved into two main clades. One clade comprises amphibious species from Africa and the Americas and shares plesiomorphic character states with Mesanthemum Körn., including palisade epidermal cells, stomatal chambers, and numerous vascular bundles in the leaf. The other clade, comprising aquatic species distributed across all continents, is characterized by derived character states, including a reduced number of vascular bundles, isodiametric epidermal cells, and the loss of stomatal chambers. These results suggest that the evolutionary history of Eriocaulon is closely tied to anatomical adaptations that facilitate colonization of aquatic environments.
A synopsis of genus Ammannia L. (Lythraceae) in India
Section: Articles Keywords: Ammannia, macrophyte, Myrtales, India, taxonomy The genus Ammannia L. (Lythraceae) in India is revised and a taxonomic synopsis is presented. In this study, nine species are recognized. Ammania nagpurensis T.Mathew and M.P.Nayar have been synonymized under A. multiflora. A key to the species, along with brief descriptions, phenology, habitat preference, distribution, and conservation status are provided. Additionally, detailed taxonomic and nomenclatural notes are presented to aid in species identification and to reconcile ambiguities in taxonomic treatments.
Structural Diversity of Flowers and Pollination Ecology in Podostemaceae
Section: Articles Keywords: Aquatic angiosperms, evolution, floral biology, perianth, spathella, pollination diversity Podostemaceae, or “river-weeds,” are a diverse family of freshwater angiosperms adapted to fast-flowing tropical and subtropical rivers. With over 300 species, they exhibit remarkable morphological variation across regions, especially between New World and Old-World taxa. Their life-cycle is tightly synchronized with seasonal water levels, with flowering and seed production occurring as waters recede. These plants rely solely on sexual reproduction, making pollination a key evolutionary driver for diversification. Different pollination strategies, melittophily, anemophily, and self-pollination have been reported within the family. However, integration of floral morphology and pollination biology remains limited. Thus, an overview of reproductive characters in Podostemaceae is presented, focussing on characters that are useful in understanding the pollination strategies and functional floral morphology in the family. This review synthesizes current knowledge to explore how pollination systems and floral traits have shaped the evolutionary trajectory of Podostemaceae.
Taxonomic revision of genus Potamogeton (Potamogetonaceae) in Kashmir Himalaya, India
Section: Monographs/Revisions Keywords: Potamogeton species, taxonomy, morphology, first report, Kashmir Himalaya Potamogeton L. (Potamogetonaceae) is one of the diverse genera of aquatic plants. Owing to its reduced floral morphology and high phenotypic plasticity, the genus has remained taxonomically challenging. This study presents taxonomic revision of Potamogeton in Kashmir Himalaya, based on comprehensive field collections made over the last decade (2010–2020), supplemented with investigations on earlier herbarium collections. During the present study, aquatic habitats across the Kashmir Himalaya were surveyed, and 15 study sites were selected for detailed sampling spanning an elevation gradient of 1595 to 2180 m asl. The study records 12 Potamogeton species in the region, with detailed morphological characterization, identification key, line drawings, and photographs. The three species, namely, P. amblyophyllus C.A. Meyer, P. berchtoldii Fieber, and P. trichoides Cham. & Schltdl. are the first-time reports from this region, while the latter two species are new distribution records for India as well. Overall, the study brings clarity to the taxonomy of Potamogeton - the largest aquatic genus in Kashmir Himalaya, and the findings have practical implications in the sustainable management and restoration of aquatic ecosystems in this Himalayan region, with learnings for neighboring regions.
Heteranthera reniformis (Pontederiaceae): A new addition to the Asian continent from India
Section: New Reports Keywords: Heteranthera reniformis, new addition, India, Asia Heteranthera reniformis (Pontederiaceae) is recently collected from the Vyenkatapur village, Sironcha taluka, Gadchiroli district, Maharashtra. It is reported here as a new record for the continent of Asia. A comprehensive taxonomic account is provided with description, photographs and distribution to facilitate easy identification of the species in the field.
The status and conservation of Malabar River-lily (Crinum malabaricum) (Liliopsida: Amaryllidaceae)
Section: Articles Keywords: Ecology, Conservation, Laterite Hills, Kerala The Malabar river-lily (Crinum malabaricum Lekhak & S.R.Yadav) is endemic to northern Kerala, south-western India, it was described new to science in 2012. It is native to seasonal rivers flowing over laterite at 80-100 m above sea level, in an area of approximately 5 x 10 km in Kannur and Kasaragod Districts. Populations are limited upstream by reaches involving steeper gradients with faster flow and downstream by deeper water over silt. It typically forms dense stands covering the entire channel with leaves forming a dense mat as water levels drop. Population counts suggest that the global population is more than 25,000 individuals. All known populations are abundantly fertile, flowering and setting seed abundantly from early September to late November. C. malabaricum is a major ecosystem architect, providing shelter for fish and invertebrate communities. Overall, known populations of C. malabaricum may be considered stable and relatively secure, although there is potential for local actions to affect all populations. The apparent absence of a mechanism for formal protection of sites supporting C. malabaricum highlights the need for surveys of potentially suitable habitat within the known range of the species, as well as for monitoring of all known populations to identify population trends.
Microecology and floristic diversity of seasonal wetlands of a lateritic plateau of South India
Section: Articles Keywords: Biodiversity, Conservation, Ecology, Ephemeral pools, Laterite flora, Northern Kerala An analysis of the microecology and floristic diversity of the seasonal pools on the Madayippara lateritic plateau, located in Kannur District of Kerala, South India, was conducted. Temporary wetlands of varying sizes are formed during the rainy season, supporting a large number of habitat-specific flowering plants, a greater number of which are endemic, and a few belong to various threat categories. The seasonal pools vary in their size, soil cover and texture, and are subjected to extreme diurnal changes in temperature due to the high surfaceto-volume ratio. They are characterised by high variation in soil temperature and water pH between pools and between seasons, extreme variation of water temperature in different seasons and in different hours of a day, and also hold maximum moisture content with extreme variation in different seasons. The soil type in most of the seasonal pools is sandy loam, and is the richest with respect to soil nutrients. The occurrence of high diversity of carnivorous plants in these nutrient-rich habitats is ascribed to the limitation in nutrient absorption, resulting from factors such as low pH, inundation and low phosphorus levels. Seasonal pools are highly specialised microhabitats active only in the monsoon period to support several specialised species showing a high degree of endemism owing to their characteristic microecology.
Typification of Candollean names in the tribe Gnaphalieae (Asteraceae)
Section: Typification/Combinations Keywords: Anaphalis, Helichrysum, Lectotype, Pseudognaphalium Revisionary studies on the tribe Gnaphalieae of Asteraceae (subfam. Asteroideae) in southern India could identify many names attached to different collections at various herbaria, without precise original materials designated as types. Candollean names of Anaphalis notoniana DC., Helichrysum buddleioides DC., and Pseudognaphalium hypoleucum (DC.) Hilliard & B.L.Burtt, have been typified following the latest botanical code.
Anaphalis, Helichrysum, Lectotype, Pseudognaphalium
Neotypification of the name Diplomeris pulchella (Orchidaceae)
Section: Typification/Combinations Keywords: Diplomeris pulchella, Nomenclature, Typification, Wallich Diplomeris pulchella D.Don (Orchidaceae) was described with an obscure indication of the type, referring only to a Wallich collection from Nepal. Subsequent searches for Wallich specimens from Nepal failed to locate any relevant material. However, a specimen of D. pulchella collected by Wallich from Sylhet, Bangladesh, is preserved at BM. It remains uncertain whether Don mistakenly cited the locality as “Nepalia” instead of Sylhet, or whether the BM specimen does not represent original material. As the BM specimen cannot be confidently confirmed as original material, it is here designated as the neotype.
Diplomeris pulchella, Nomenclature, Typification, Wallich
Taxonomic reassessment of Impatiens verecunda (Balsaminaceae) and its synonymization with I. cordata in the Western Ghats, India
Section: Articles Keywords: Anamalai hills, Devikulam, Idukki, Impatiens anaimudica, Kerala Historical records, such as those by J.D. Hooker and subsequent studies, have noted taxonomic complexities in Impatiens verecunda Hook.f. and its relationship with I. cordata Wight and I. anaimudica C.E.C.Fisch. Field surveys in Devikulam, Kerala, discovered specimens resembling I. verecunda, prompting detailed morphological comparisons with I. cordata and I. anaimudica. The plants exhibited similarities to I. cordata, differing only in habitat-driven traits like short stature and short floral spurs, confirmed the synonymization of I. verecunda under I. cordata. Conversely, I. anaimudica remains distinct due to its lenticelled stems, crimson flowers, and unique spur morphology. Further studies on I. cordata populations revealed variations in life history, habit, flower color, spur length, and floral morphology, influenced by environmental conditions. A revised description of I. cordata is presented to account for these variations and clarify its distinction from closely related taxa like I. elegans Bedd.
Anamalai hills, Devikulam, Idukki, Impatiens anaimudica, Kerala
Physalis cordata (Solanaceae): a new record for India
Section: New Reports Keywords: Physalis, North 24 Parganas district, West Bengal, Invasive species, Native of Americas Physalis cordata Houst. ex Mill. (Solanaceae), a native of North and South America has been collected from North 24-Parganas district of West Bengal, India in 2024 is reported here as an addition to the Flora of India. Morphological description, location map and a photo plate are provided here for its proper recognition.
Physalis, North 24 Parganas district, West Bengal, Invasive species, Native of Americas
A taxonomic revision of the genus Justicia (Acanthaceae) in Peninsular India
Section: Monographs/Revisions Keywords: Conservation Assessment,, Justicieae, Lectotypification, Synonymization A detailed taxonomic account of the genus Justicia L. in Peninsular India is provided, with 18 species recognized. Lectotypifications of six names are carried out. Nine taxa are treated as synonyms: Justicia diffusa var. orbiculata C.B.Clarke of J. diffusa Willd.; J. nilgherrensis (Nees) Wall. ex C.B.Clarke and J. tamilnadensis P.Raja & Soosairaj of J. trinervia Vahl; J. nagpurensis V.A.W.Graham, J. notha C.B.Clarke and J. pathanamthittiensis Remadevi & Binojk. of J. procumbens L.; J. quinqueangularis var. kawalii Annamma & Venu of J. quinqueangularis J.Koenig ex Roxb.; J. salsoloides T.Anderson of J. tranquebariensis L.f. and J. vahlii var. rupicola (J.L.Ellis) Pull., Moulali & Sandhyar. of J. vahliana Schult. Detailed descriptions, photographic images and a key for identifying species in Peninsular India are provided along with data on phenology, distribution and conservation status.
Section: Book Reviews Authored by Natesh S. Illustrations by Sagar Bhowmick. Published by Roli Books, Delhi, India. Hardbound. ISBN: 9789392130342. Pages 256. Price: (INR) 1995.00
Note on taxonomy and typification of Vigna hainiana Babu, Gopinathan & Sharma ( =Phaseolus wightii W. & A.)
Section: Typification/Combinations Vigna hainiana Babu, Gopinathan & Sharma, collected from north-western and eastern parts of India, has been studied. Characters for differentiating this species have been delineated. The type indicated previously for V. hainiana was incorrect; Wall. L. n. 5591 is the lectotype for this species.
Book Review: Know Your Grass Genera Through Hand Lens
Section: Book Reviews -
The Genus Ludwigia (Onagraceae) in India
Section: Articles Keywords: India, Ludwigia, Taxonomy The genus Ludwigia L. consists of seven species and one infraspecific taxon in India, of which L. decurrens forms the first report for India. This revision provides a key to species, descriptions and illustrations along with data on phenology, distribution and notes on ecology.
Solanum cordatum (Solanaceae) – A new record to Southern India
Section: New Reports Keywords: Kolli hills, New record, Solanum cordatum, Southern India While preparing an inventory of flowering plants of the Kolli hills, Namakkal district, Tamil Nadu, Southern India, some specimens of Solanum L. were collected and identified as S. cordatum Forssk. On scrutiny of literature, it is revealed that this species is known only from Gujarat in India and forms a new record to Southern India. Hence, a detailed description, phenology and illustration are provided to facilitate easy identification of the species.
Syzygium claviflorum (Myrtaceae) – A new record for South India
Section: New Reports Keywords: Myrtaceae, New record, South India, Syzygium claviflorum Syzygium claviflorum (Roxb.) Wall. ex A.M. Cowan et Cowan, a Myrtaceous tree species is reported for the first time for South India from Agasthyamalai Biosphere Reserve of the southern Western Ghats. A brief description and illustration of the species are provided herewith for easy identification.
Rediscovery of Pogostemon nilagiricus (Lamiaceae), a steno-endemic and critically endangered aromatic species
Section: Articles Keywords: Aromatic plant, Endemic, Lamiaceae, Nilgiri, Pogostemon Pogostemon nilagiricus Gamble (Lamiaceae) is rediscovered from Nilgiri hills, the type locality, after a gap of 97 years. A detailed description, photograph and note on its taxonomy are provided. Current threat status has also been assessed based on the recent botanical explorations.
Lakshmia Veldk. (Poaceae), A New Genus from the Western India and Sri Lanka
Section: New Taxa Keywords: Andropogon venustus, Gramineae, Hemisorghum, India, Lakshmia, Sri Lanka, Taxonomy Andropogon venustus (Gramineae) from the Western India and Sri Lanka represents an undescribed genus. It is described.
Obituary: Prof. E. Govindarajalu (1925-1997)
Section: Obituaries -
Peristylus tentaculatus (Orchidaceae): A new record for India from the Western Ghats of Kerala
Section: New Reports Keywords: India, Kerala, New Record, Peristylus tentaculatus, Western Ghats Peristylus tentaculatus (Lindl.) J.J. Sm. (Orchidaceae), an orchid native to China, is reported here for the first time from India. Detailed description, notes on distribution and photographs are provided for accurate identification.
Identity of Ficus amplocarpa and F. guttata (Moraceae), the two closely allied south Indian endemic species and their conservation status
Section: Articles Keywords: Conservation, Ficus amplocarpa, F. guttata, F. laevis, Synoecia Identity of two closely allied endemic Ficus species namely F. amplocarpa Govind. & Masil. and F. guttata (Wight) King from southern India are discussed here along with key, updated nomenclature, conservation status, and photographs. In addition, the placement of F. guttata in subgenus Synoecia, non-existence of F. laevis Blume in peninsular India and author attribution of F. guttata are clarified.
Lectotypifications in Flemingia (Leguminosae)
Section: Typification/Combinations Keywords: Flemingia, Lectotype, Roxburgh Drawing, Wallich Catalogue Flemingia fluminalis C.B. Clarke ex Prain, F. nana Roxb. ex W.T. Aiton, F. procumbens Roxb. and F. semialata Roxb. ex W.T. Aiton are lectotypified here.
Lectotypification of Cyperus blatteri and notes on its new synonym C. pentabracteatus (Cyperaceae)
Section: Articles Keywords: Cyperaceae, Cyperus, Endemic, Heterotypic Synonym, Lectotype, Maharashtra The name Cyperus blatteri (McCann) Wad.Khan (= Mariscus blatteri McCann) is lectotypified and C. pentabracteatus Govind. & Hemadri is reduced here as a heterotypic synonym of C. blatteri.
Teramnus hookerianus, a heterotypic synonym of T. labialis (Leguminosae: Papilionoideae)
Section: Articles Keywords: Heterotypic Synonym, Papilionoideae, Teramnus hookerianus, T. labialis Teramnus hookerianus A. Sen is relegated here to a heterotypic synonym of T. labialis (L.f.) Spreng.
Obituary: Madhavan Parameswaran Nayar (27 January 1932–9 December 2016)
A report on XXVI Annual Conference of Indian Association for Angiosperm Taxonomy (IAAT) and International Seminar on Conservation and Sustainable Utilization of Biodiversity
Section: Articles -
Linaria canadensis (Plantaginaceae): A new record for India
Section: New Reports Keywords: India, Linaria canadensis, Megamalai Hills, New Record, Tamil Nadu Linaria canadensis (L.) Dum.Cours., a species native to North America, is reported here as a new distributional record for India from Tamil Nadu. Detailed description and photographs are provided to facilitate accurate identification.