# สกุลขี้เหล็ก
สกุลขี้เหล็ก หรือ Senna (มาจาก ภาษาอาหรับ sanā) เป็นสกุลขนาดใหญ่ในวงศ์ Fabaceaeและวงศ์ย่อย Caesalpinioideae พืชในสกุลนี้เป็นพืชท้องถิ่นในเขตร้อน พบในเขตอบอุ่นไม่กี่ชนิด จำนวนสปีชีส์ประมาณ 260 - 350 สปีชีส์Randell, B. R. and B. A. Barlow. 1998. Senna. pp 89-138. In: A. S. George (executive editor). Flora of Australia volume 12. Australian Government Publishing Service: Canberra, Australia. สปีชีส์ของสกุลนี้คือ Senna alexandrina มีประมาณ 50 สปีชีส์ในสกุลนี้ที่เป็นพืชปลูกHuxley, A., et al. (1992). The New Royal Horticultural Society Dictionary of Gardening. The Macmillan Press, Limited: London. The Stockton Press: New York. ISBN 978-0-333-47494-5 (set).
 ตัวอย่างสปีชีส์ 
thumb|right|Senna aversiflora
thumb|right|Senna didymobotrya
thumb|right|Senna lindheimeriana
thumb|right|Senna multiglandulosa
thumb|right|Senna surattensis

 Senna acclinis  (F.Muell.) RandellGRIN Species Records of Senna.  Germplasm Resources Information Network (GRIN).
 Senna aciphylla  (Benth.) Randell
 Senna aculeata  (Benth.) H.S.Irwin & Barneby
 Senna alata  (L.) Roxb. - candlebush, Christmas candle, empress candleplant, candlestick tree, ringworm bush, seven-golden-candles
 Senna alexandrina Mill. - Alexandrian senna, Indian senna, Tinnevelly senna, true senna
 Senna angulata  (Vogel) H.S.Irwin & Barneby
 Senna appendiculata  (Vogel) Wiersema (syn. S. australis)
 Senna armata  (S.Watson) H.S.Irwin & Barneby
 Senna artemisioides  (Gaudich. ex DC.) Randell - grey cassia, leafless cassia, woody cassia, puntybush, silverbush
 Senna auriculata  (L.) Roxb. - avaram, Matara-tea, tanner's cassia
 Senna aversiflora  (Herbert) H.S.Irwin & Barneby
 Senna bacillaris - West Indian showertree
 Senna barclayana - pepper-leaf senna, smooth senna, yellow peabush
 Senna bicapsularis - rambling senna, Christmas bush, money bush, yellow candlewood
 Senna birostris  (Vogel) H.S.Irwin & Barneby
 Senna candolleana  (Vogel) H.S.Irwin & Barneby
 Senna cardiosperma  (F.Muell.) RandellSenna cardiosperma. The Plant List.
 Senna caudata  (Standl.) H.S.Irwin & Barneby (Costa Rica, Panama)
 Senna cobanensis  (Britton & Rose) H.S.Irwin & Barneby
 Senna corymbosa - Argentine senna, Argentine wild sensitive plantSenna. Integrated Taxonomic Information System (ITIS).
 Senna covesii  (A.Gray) H.S.Irwin & Barneby - Coues' cassia, Coves' cassia, desert senna
 Senna cumingii  (Hook. & Arn.) H.S.Irwin & Barneby
 Senna didymobotrya  (Fresen.) H.S.Irwin & Barneby - candelabra-tree, peanut butter cassia, African senna
 Senna domingensis  (Spreng.) H.S.Irwin & Barneby (Cuba, Hispaniola)
 Senna fruticosa  (Mill.) H.S.Irwin & Barneby
 Senna garrettiana  (Craib) H.S.Irwin & Barneby
 Senna gaudichaudii  (Hook. & Arn.) H.S.Irwin & Barneby - climbing cassia, heuhiuhi (Pacific Islands, Queensland) 
 Senna hayesiana  (Britton & Rose) H.S.Irwin & Barneby
 Senna hebecarpa - American senna, wild senna
 Senna hirsuta  (L.) H.S.Irwin & Barneby - woolly senna, woolly wild sensitive plant
 Senna italica Mill. - Port Royal senna, dog senna, Italian senna, Spanish senna
 Senna ligustrina  (L.) H.S.Irwin & Barneby - privet senna
 Senna lindheimeriana  (Scheele) H.S.Irwin & Barneby - velvet-leaf senna, showy senna
 Senna macranthera  (Collad.) H.S.Irwin & Barneby
 Senna magnifolia  (F.Muell.) RandellSenna magnifolia. The Plant List.
 Senna marilandica  (L.) Link - Maryland senna
 Senna martiana  (Benth.) H.S.Irwin & Barneby
 Senna martiana  (Benth.) H.S.Irwin & Barneby
 Senna mexicana - Mexican senna
 Senna multiglandulosa  (Jacq.) H.S.Irwin & Barneby - glandular senna, downy senna
 Senna multijuga (Rich.) H.S.Irwin & Barneby  - false sicklepod
 Senna nicaraguensis  (Benth.) H.S.Irwin & Barneby
 Senna nitida  (Rich.) H.S. Irwin & Barneby - hediondilla
 Senna notabilis  (F.Muell.) RandellSenna notabilis. Germplasm Resources Information Network (GRIN).
 Senna obtusifolia  (L.) H.S.Irwin & Barneby - coffee-weed, java-bean, American sicklepod
 Senna occidentalis  (L.) Link - antbush, coffee-senna, negro-coffee, septicweed, stinkingweedSenna occidentalis.  Germplasm Resources Information Network (GRIN).
 Senna odorata  (R. Morris) Randall
 Senna oligoclada  (F.Muell.) RandellSenna oligoclada. The Plant List.
 Senna orcuttii  (Britton & Rose) H.S.Irwin & Barneby - Orcutt's senna, Orcutt's wild sensitive plant
 Senna pallida  (Vahl) H.S.Irwin & Barneby
 Senna papillosa  (Britton & Rose) H.S.Irwin & Barneby
 Senna pendula  (Willd.) H.S.Irwin & Barneby - Easter cassia, valamuerto
 Senna pilosior  (B.L.Rob. ex J.F.Macbr.) H.S.Irwin & Barneby Trans-Pecos senna, Trans-Pecos wild sensitive plant
 Senna pleurocarpa  (F.Muell.) Randell - stripe-pod cassiaSenna pleurocarpa.  Germplasm Resources Information Network (GRIN).
 Senna polyphylla  (Jacq.) H.S. Irwin & Barneby - retama prieta
 Senna pumilio - dwarf senna
 Senna purpusii  (Brandegee) H.S.Irwin & Barneby
 Senna racemosa  (Mill.) H.S.Irwin & Barneby - limestone senna
 Senna reticulata Willd
 Senna ripleyana H.S.Irwin & Barneby - Ripley's senna, Ripley's wild sensitive plant
 Senna roemeriana  (Scheele) H.S.Irwin & Barneby - twoleaf senna, Roemer senna
 Senna rostrata  (Mart.) H.S.Irwin & Barneby - New Mexico wild sensitive plant
 Senna rugosa  (G.Don.) H.S.Irwin & Barneby
 Senna scandens
 Senna septemtrionalis  (Viv.) H.S.Irwin & Barneby - arsenic-bush, Dooleyweed, laburnum, smooth senna
 Senna siamea (Lam.) H.S.Irwin & Barneby - kassodtree, Siamese cassia, Thai cassia, Thailand shower
 Senna socotrana
 Senna sophera - algarrobilla
 Senna spectabilis  (DC.) H.S.Irwin & Barneby - casia amarilla
 Senna splendida  (Vogel) H.S.Irwin & Barneby
 Senna surattensis  (Burm.f.) H.S.Irwin & Barneby (syn. S. speciosa Roxb.) - glossy shower
 Senna sulfurea  (Collad.) H.S.Irwin & Barneby
 Senna timoriensis  (DC.) H.S.Irwin & Barneby
 Senna tora L. - sickle wild sensitive-plant, sickle senna, foetid cassia
 Senna trolliiflora
 Senna undulata  (Vahl) H.S.Irwin & Barneby
 Senna uniflora
 Senna venusta  (F.Muell.) Randell
 Senna wislizeni - Wislizenus' senna, shrubby senna