The Senna: A Plant of Diverse Beauty and Utility
As a plant enthusiast, I’ve always been fascinated by the sheer variety and adaptability of the Senna genus. These flowering plants, belonging to the legume family, boast a global presence, thriving in tropical regions and even making appearances in some temperate zones. With an estimated 287 species, the Senna genus offers a captivating array of forms, from shrubs and trees to perennial herbs. Â
A World of Senna
One of the things that I find most striking about Senna plants is their distinctive foliage. The leaves are arranged alternately along the stems and are characterized by their paripinnate structure, meaning they have an even number of leaflets arranged in pairs. Each leaf also has a small stipule at its base, which often falls off as the leaf matures.
But the true showstoppers are the flowers. Typically a vibrant yellow, they can also be found in shades of pink, orange, and red. These blossoms are not just a feast for the eyes; they also play a crucial role in the plant’s reproductive cycle, attracting pollinators such as bees and butterflies.
The fruit of the Senna plant is a pod, which varies in size and shape depending on the species. These pods contain the seeds, which can be dispersed by wind, water, or animals.
Senna Species: A Diverse Family
The Senna genus is incredibly diverse, with species adapted to a wide range of habitats. Here are: Â
- Senna acanthoclada (Griseb.) H.S.Irwin & Barneby
- Senna acatlanensis C.Rojas-Mart. & A.Delgado
- Senna acclinis (F.Muell.) Randell
- Senna aciphylla (Benth. ex A.Gray) Randell
- Senna aculeata (Pohl ex Benth.) H.S.Irwin & Barneby
- Senna acunae (Borhidi) A.Barreto & Yakovlev
- Senna acuparata H.S.Irwin & Barneby
- Senna acuruensis (Benth.) H.S.Irwin & Barneby
- Senna acutisepala (Benth.) H.S.Irwin & Barneby
- Senna affinis (Benth.) H.S.Irwin & Barneby
- Senna alata (L.) Roxb.
- Senna alexandrina Mill.
- Senna andrieuxii (Benth.) H.S.Irwin & Barneby
- Senna angulata (Vogel) H.S.Irwin & Barneby
- Senna angustisiliqua (Lam.) H.S.Irwin & Barneby
- Senna ankaranensis Du Puy & R.Rabev.
- Senna anthoxantha (Capuron) Du Puy
- Senna aphylla (Cav.) H.S.Irwin & Barneby
- Senna apiculata (M.Martens & Galeotti) H.S.Irwin & Barneby
- Senna appendiculata (Vogel) Wiersema
- Senna apsidoneura (H.S.Irwin & Barneby) H.S.Irwin & Barneby
- Senna araucarietorum H.S.Irwin & Barneby
- Senna argentea (Kunth) H.S.Irwin & Barneby
- Senna arida (Rose) H.S.Irwin & Barneby
- Senna aristeguietae H.S.Irwin & Barneby
- Senna armata (S.Watson) H.S.Irwin & Barneby
- Senna arnottiana (Gillies) H.S.Irwin & Barneby
- Senna artemisioides (Gaudich. ex DC.) Randell
- Senna atomaria (L.) H.S.Irwin & Barneby
- Senna aurantia (Ruiz & Pav. ex G.Don) H.S.Irwin & Barneby
- Senna auriculata (L.) Roxb.
- Senna aversiflora (Herb.) H.S.Irwin & Barneby
- Senna aymara H.S.Irwin & Barneby
- Senna baccarinii (Chiov.) Lock
- Senna bacillaris (L.f.) H.S.Irwin & Barneby
- Senna bahiensis A.G.Lima & V.C.Souza
- Senna barclayana (Sweet) Randell
- Senna barnebyana Lass.
- Senna barronfieldii (Colla) Hewson
- Senna bauhinioides (A.Gray) H.S.Irwin & Barneby
- Senna benitoensis (Britton & P.Wilson) H.S.Irwin & Barneby
- Senna bicapsularis (L.) Roxb.
- Senna biglandularis A.O.Araujo & V.C.Souza
- Senna birostris (Dombey ex Vogel) H.S.Irwin & Barneby
- Senna bosseri Du Puy & R.Rabev.
- Senna bracteosa D.B.O.S.Cardoso & L.P.Queiroz
- Senna brongniartii (Gaudich.) H.S.Irwin & Barneby
- Senna burkartiana (Villa) H.S.Irwin & Barneby
- Senna cajamarcae H.S.Irwin & Barneby
- Senna cana (Nees & Mart.) H.S.Irwin & Barneby
- Senna candolleana (Vogel) H.S.Irwin & Barneby
- Senna cardiosperma (F.Muell.) Randell
- Senna catingae (Harms) L.P.Queiroz
- Senna caudata (Standl.) H.S.Irwin & Barneby
- Senna cearensis Afr.Fern.
- Senna centranthera H.S.Irwin & Barneby
- Senna cernua (Balb.) H.S.Irwin & Barneby
- Senna charlesiana (Symon) Randell
- Senna chloroclada (Harms) H.S.Irwin & Barneby
- Senna chrysocarpa (Desv.) H.S.Irwin & Barneby
- Senna circinnata (Benth.) Randell
- Senna cladophylla (W.Fitzg.) Randell
- Senna clavigera (Domin) Randell
- Senna cobanensis (Britton) H.S.Irwin & Barneby
- Senna coimbrae M.Nee & Barneby
- Senna collicola H.S.Irwin & Barneby
- Senna confinis (Greene) H.S.Irwin & Barneby
- Senna corifolia (Benth.) H.S.Irwin & Barneby
- Senna cornigera H.S.Irwin & Barneby
- Senna coronilloides (Benth.) Randell
- Senna corymbosa (Lam.) H.S.Irwin & Barneby
- Senna costata (J.F.Bailey & C.T.White) Randell
- Senna covesii (A.Gray) H.S.Irwin & Barneby
- Senna crassiramea (Benth.) H.S.Irwin & Barneby
- Senna crotalarioides (Kunth) H.S.Irwin & Barneby
- Senna cruckshanksii (Hook. & Arn.) H.S.Irwin & Barneby
- Senna cuatrecasasii H.S.Irwin & Barneby
- Senna cumingii (Hook. & Arn.) H.S.Irwin & Barneby
- Senna curvistyla (J.M.Black) Randell
- Senna cushina (J.F.Macbr.) H.S.Irwin & Barneby
- Senna cuthbertsonii (F.Muell.) Randell
- Senna dardanoi Afr.Fern. & P.Bezerra
- Senna dariensis (Britton & Rose) H.S.Irwin & Barneby
- Senna davidsonii (V.Singh) V.Singh
- Senna demissa (Rose) H.S.Irwin & Barneby
- Senna didymobotrya (Fresen.) H.S.Irwin & Barneby
- Senna divaricata (Nees & Blume) Lock
- Senna domingensis (Spreng.) H.S.Irwin & Barneby
- Senna dryadica A.G.Lima & Mansano
- Senna durangensis (Rose) H.S.Irwin & Barneby
- Senna ellisiae (Brenan) Lock
- Senna ferraria (Symon) Randell
- Senna flexuosa (Randell) Randell
- Senna × floribunda (Cav.) H.S.Irwin & Barneby
- Senna foetidissima (Ruiz & Pav. ex G.Don) H.S.Irwin & Barneby
- Senna formosa H.S.Irwin & Barneby
- Senna franciscana A.G.Lima & Mansano
- Senna fruticosa (Mill.) H.S.Irwin & Barneby
- Senna galeottiana (M.Martens) H.S.Irwin & Barneby
- Senna gardneri (Benth.) H.S.Irwin & Barneby
- Senna garrettiana (Craib) H.S.Irwin & Barneby
- Senna gaudichaudii (Hook. & Arn.) H.S.Irwin & Barneby
- Senna georgica H.S.Irwin & Barneby
- Senna glaucifolia (Randell) Randell
- Senna gloriosa (H.S.Irwin & Barneby) A.G.Lima & Mansano
- Senna glutinosa (DC.) Randell
- Senna goniodes (A.Cunn. ex Benth.) Randell
- Senna gossweileri (Baker f.) Lock
- Senna guatemalensis (Donn.Sm.) H.S.Irwin & Barneby
- Senna gundlachii (Urb.) H.S.Irwin & Barneby
- Senna hamersleyensis (Symon) Randell
- Senna harleyi H.S.Irwin & Barneby
- Senna haughtii (J.F.Macbr.) H.S.Irwin & Barneby
- Senna hayesiana (Britton & Rose) H.S.Irwin & Barneby
- Senna hebecarpa (Fernald) H.S.Irwin & Barneby
- Senna heptanthera Randell
- Senna herzogii (Harms) H.S.Irwin & Barneby
- Senna hilariana (Benth.) H.S.Irwin & Barneby
- Senna hirsuta (L.) H.S.Irwin & Barneby
- Senna holosericea (Fresen.) Greuter
- Senna holwayana (Rose) H.S.Irwin & Barneby
- Senna hookeriana Batke
- Senna huancabambae (Harms) H.S.Irwin & Barneby
- Senna huidobriana (Phil.) Zoellner & San Martin
- Senna huilana (Britton & Rose) H.S.Irwin & Barneby
- Senna humifusa (Brenan) Lock
- Senna incarnata (Pav. ex Benth.) H.S.Irwin & Barneby
- Senna insularis (Britton & Rose) H.S.Irwin & Barneby
- Senna intermedia (B.D.Sharma, Vivek. & Rathakr.) V.Singh
- Senna italica Mill.
- Senna itatiaiae H.S.Irwin & Barneby
- Senna juchitanensis Saynes & R.Torres
- Senna koelziana H.S.Irwin & Barneby
- Senna kuhlmannii (Hoehne) H.S.Irwin & Barneby
- Senna kurtzii (Harms) H.S.Irwin & Barneby
- Senna lactea (Vatke) Du Puy
- Senna lasseigniana H.S.Irwin & Barneby
- Senna latifolia (G.Mey.) H.S.Irwin & Barneby
- Senna leandrii (Ghesq.) Du Puy
- Senna lechriosperma H.S.Irwin & Barneby
- Senna leiophylla (Vogel) H.S.Irwin & Barneby
- Senna leptoclada (Benth.) Randell
- Senna ligustrina (L.) H.S.Irwin & Barneby
- Senna lindheimeriana (Scheele) H.S.Irwin & Barneby
- Senna longiglandulosa (Benth.) H.S.Irwin & Barneby
- Senna longiracemosa (Vatke) Lock
- Senna loretensis (Killip & J.F.Macbr.) H.S.Irwin & Barneby
- Senna lourteigiana H.S.Irwin & Barneby
- Senna macranthera (DC. ex Collad.) H.S.Irwin & Barneby
- Senna macrophylla (Kunth) H.S.Irwin & Barneby
- Senna magnifolia (F.Muell.) Randell
- Senna malaspinae H.S.Irwin & Barneby
- Senna mandonii (Benth.) H.S.Irwin & Barneby
- Senna manicula (Symon) Randell
- Senna marilandica (L.) Link
- Senna martiana (Benth.) H.S.Irwin & Barneby
- Senna mensicola (H.S.Irwin & Barneby) H.S.Irwin & Barneby
- Senna meridionalis (R.Vig.) Du Puy
- Senna mexicana (Jacq.) H.S.Irwin & Barneby
- Senna mollissima (Humb. & Bonpl. ex Willd.) H.S.Irwin & Barneby
- Senna monilifera H.S.Irwin & Barneby
- Senna monozyx (H.S.Irwin & Barneby) H.S.Irwin & Barneby
- Senna montana (B.Heyne ex Roth) V.Singh
- Senna morongii (Britton) H.S.Irwin & Barneby
- Senna mucronifera (Mart. ex Benth.) H.S.Irwin & Barneby
- Senna multifoliolata (Paul G.Wilson) H.S.Irwin & Barneby
- Senna multiglandulosa (Jacq.) H.S.Irwin & Barneby
- Senna multijuga (Rich.) H.S.Irwin & Barneby
- Senna mutisiana (Kunth) H.S.Irwin & Barneby
- Senna nana (Benth.) H.S.Irwin & Barneby
- Senna neglecta (Vogel) H.S.Irwin & Barneby
- Senna nicaraguensis (Benth.) H.S.Irwin & Barneby
- Senna nitida (Rich.) H.S.Irwin & Barneby
- Senna notabilis (F.Muell.) Randell
- Senna nudicaulis (Burkart) H.S.Irwin & Barneby
- Senna obliqua (G.Don) H.S.Irwin & Barneby
- Senna oblongifolia (Vogel) H.S.Irwin & Barneby
- Senna obtusifolia (L.) H.S.Irwin & Barneby
- Senna occidentalis (L.) Link
- Senna oligoclada (F.Muell.) Randell
- Senna orcuttii (Britton & Rose) H.S.Irwin & Barneby
- Senna organensis (Glaz. ex Harms) H.S.Irwin & Barneby
- Senna oxyphylla (Kunth) H.S.Irwin & Barneby
- Senna pachyrrhiza (L.Bravo) H.S.Irwin & Barneby
- Senna pallida (Vahl) H.S.Irwin & Barneby
- Senna papillosa (Britton & Rose) H.S.Irwin & Barneby
- Senna paposana (Phil.) Zoellner & San Martin
- Senna paradictyon (Vogel) H.S.Irwin & Barneby
- Senna paraensis (Ducke) H.S.Irwin & Barneby
- Senna pendula (Humb. & Bonpl. ex Willd.) H.S.Irwin & Barneby
- Senna pentagonia (Mill.) H.S.Irwin & Barneby
- Senna peralteana (Kunth) H.S.Irwin & Barneby
- Senna perrieri (R.Vig.) Du Puy
- Senna petersiana (Bolle) Lock
- Senna phlebadenia H.S.Irwin & Barneby
- Senna phyllodinea (R.Br.) Symon
- Senna pilifera (Vogel) H.S.Irwin & Barneby
- Senna pilocarina (Symon) Randell
- Senna pilosior (B.L.Rob.) H.S.Irwin & Barneby
- Senna pinheiroi H.S.Irwin & Barneby
- Senna pistaciifolia (Kunth) H.S.Irwin & Barneby
- Senna planitiicola (Domin) Randell
- Senna pleurocarpa (F.Muell.) Randell
- Senna pluribracteata F.S.Souto & R.T.Queiroz
- Senna pneumatica H.S.Irwin & Barneby
- Senna podocarpa (Guill. & Perr.) Lock
- Senna polyantha (Collad.) H.S.Irwin & Barneby
- Senna polyphylla (Jacq.) H.S.Irwin & Barneby
- Senna praeterita H.S.Irwin & Barneby
- Senna procumbens Randell
- Senna pumilio (A.Gray) H.S.Irwin & Barneby
- Senna punoensis Lass.
- Senna purpusii (Brandegee) H.S.Irwin & Barneby
- Senna quinquangulata (Rich.) H.S.Irwin & Barneby
- Senna racemosa (Mill.) H.S.Irwin & Barneby
- Senna reniformis (G.Don) H.S.Irwin & Barneby
- Senna reticulata (Willd.) H.S.Irwin & Barneby
- Senna rigidicaulis (Burkart ex L.Bravo) H.S.Irwin & Barneby
- Senna ripleyana (H.S.Irwin & Barneby) H.S.Irwin & Barneby
- Senna rizzinii H.S.Irwin & Barneby
- Senna robiniifolia (Benth.) H.S.Irwin & Barneby
- Senna roemeriana (Scheele) H.S.Irwin & Barneby
- Senna rostrata (Mart.) H.S.Irwin & Barneby
- Senna rugosa (G.Don) H.S.Irwin & Barneby
- Senna ruiziana (G.Don) H.S.Irwin & Barneby
- Senna rupununiensis H.S.Irwin & Barneby
- Senna ruspolii (Chiov.) Lock
- Senna saeri (Pittier) H.S.Irwin & Barneby
- Senna sandwithiana H.S.Irwin & Barneby
- Senna santanderensis (Britton & Killip) H.S.Irwin & Barneby
- Senna scabriuscula (Vogel) H.S.Irwin & Barneby
- Senna scandens (Ruiz & Pav. ex G.Don) H.S.Irwin & Barneby
- Senna septemtrionalis (Viv.) H.S.Irwin & Barneby
- Senna sericea (Symon) Albr. & Symon
- Senna siamea (Lam.) H.S.Irwin & Barneby
- Senna silvestris (Vell.) H.S.Irwin & Barneby
- Senna singueana (Delile) Lock
- Senna skinneri (Benth.) H.S.Irwin & Barneby
- Senna smithiana (Britton & Rose) H.S.Irwin & Barneby
- Senna sophera (L.) Roxb.
- Senna sousana H.S.Irwin & Barneby
- Senna spectabilis (DC.) H.S.Irwin & Barneby
- Senna spinescens (Hoffmanns. ex Vogel) H.S.Irwin & Barneby
- Senna spiniflora (Burkart) H.S.Irwin & Barneby
- Senna spinigera (Rizzini) H.S.Irwin & Barneby
- Senna splendida (Vogel) H.S.Irwin & Barneby
- Senna stenophylla (Britton) H.S.Irwin & Barneby
- Senna stipulacea (W.T.Aiton) H.S.Irwin & Barneby
- Senna stowardii (S.Moore) Randell
- Senna stricta (Randell) Randell
- Senna suarezensis (Capuron) Du Puy
- Senna subtrijuga H.S.Irwin & Barneby
- Senna subulata (Griseb.) H.S.Irwin & Barneby
- Senna sulfurea (DC. ex Collad.) H.S.Irwin & Barneby
- Senna surattensis (Burm.f.) H.S.Irwin & Barneby
- Senna symonii (Randell) Randell
- Senna talpana H.S.Irwin & Barneby
- Senna tapajozensis (Ducke) H.S.Irwin & Barneby
- Senna tenuifolia (Vogel) H.S.Irwin & Barneby
- Senna timoriensis (DC.) H.S.Irwin & Barneby
- Senna tocotana (Rose ex Britton & Killip) Silverst.
- Senna tonduzii (Standl.) H.S.Irwin & Barneby
- Senna tora (L.) Roxb.
- Senna trachypus (Mart. ex Benth.) H.S.Irwin & Barneby
- Senna trianae H.S.Irwin & Barneby
- Senna trolliiflora H.S.Irwin & Barneby
- Senna tropica (Vell.) H.S.Irwin & Barneby
- Senna truncata (Brenan) Lock
- Senna tuhovalyana (Aké Assi) Lock
- Senna uncata H.S.Irwin & Barneby
- Senna undulata (Benth.) H.S.Irwin & Barneby
- Senna uniflora (Mill.) H.S.Irwin & Barneby
- Senna unijuga (Rose) H.S.Irwin & Barneby
- Senna urmenetae (Phil.) H.S.Irwin & Barneby
- Senna vargasii (Schery) H.S.Irwin & Barneby
- Senna velutina (Vogel) H.S.Irwin & Barneby
- Senna venusta (F.Muell.) Randell
- Senna versicolor (Meyen ex Vogel) H.S.Irwin & Barneby
- Senna viarum (Little) H.S.Irwin & Barneby
- Senna viciifolia (Benth.) H.S.Irwin & Barneby
- Senna viguierella (Ghesq.) Du Puy
- Senna villosa (Mill.) H.S.Irwin & Barneby
- Senna viminea (L.) H.S.Irwin & Barneby
- Senna weddelliana H.S.Irwin & Barneby
- Senna williamsii (Britton & Rose) H.S.Irwin & Barneby
- Senna wislizeni (A.Gray) H.S.Irwin & Barneby
- Senna wurdackii H.S.Irwin & Barneby
Senna and Humanity: A Longstanding Relationship
Humans have interacted with Senna plants for centuries, recognizing their value in various aspects of life.
Perhaps the most well-known use of Senna is in traditional medicine. Some species, like Senna alexandrina, are renowned for their laxative properties and have been used for centuries to treat constipation. Other species have been employed to address a range of ailments, from skin conditions to digestive issues.
Beyond medicine, Senna plants have also found their place in other human endeavors. Some species are cultivated as ornamentals, their vibrant flowers adding a splash of color to gardens and landscapes. Others are utilized for their tannins, which are used in the leather tanning process. And in some regions, Senna species are even used as a source of food or fodder.
The Future of Senna
As we continue to learn more about the Senna genus, I’m excited to see how our relationship with these plants evolves. With their diverse properties and adaptability, Senna plants hold great potential for future applications in medicine, agriculture, and other fields.
Whether it’s harnessing their medicinal properties, appreciating their ornamental beauty, or exploring their potential in sustainable agriculture, the Senna genus offers a wealth of possibilities for the future. I, for one, am eager to see what discoveries and innovations lie ahead in our ongoing exploration of these fascinating plants.