.'582 



LEGUMINOS^E. CCXXIII. MIMOSA. 



heads. Leaves usually sensible to the touch, as in the common 

 sensitive plant. 



SECT. I. EUMIMOSA (from en, well, and Mimosa ; genuine 

 species). D. C. legum. mem. xii. prod. 2. p. 425. Legumes 

 compressed, moniliform, particularly with the ribs contracted at 

 the articulations. Flowers rose-coloured. 



1 . Sensitives. Leaves with 1 pair of pinna?, and with 2 pairs 

 of leaflets on each pinna, the inner pair smaller than the outer 

 pair. Stamens 4, rarely 5. Leaves in most of the species sen- 

 sible to the toucli, 



1 M. DE'BILIS (Humb. et Bonpl. in Willd. spec. 4. p. 1029.) 

 stem herbaceous, simple, rather prickly, glabrous, unarmed at 

 the base of the petioles, but hairy ; leaflets obovate, mucronate, 

 clothed on both surfaces with impressed pubescence ; heads of 

 flowers elliptic, solitary. Q. S. Native of South America, 

 near Caripe. H. B. et Kunth, nov. gen. amer. 6. p. 248. 

 Flowers rose-coloured. Pods unknown. 



Weak Sensitive-plant. PI. 1 to 2 feet. 



2 M. A'LBIDA (Humb. et Bonpl. in Willd. spec. 4. p. 1030.) 

 branches clothed with canescent pubescence, prickly ; leaflets 

 dimidiately-oblong, acute, pubescent ; petioles unarmed ; heads 

 of flowers twin. Tj . S. Native of Peru, near Moche, in sand 

 by the sea-side. A creeping shrub, very nearly allied to M. scn- 

 sitiva. Legume hispid, 4-celled, hardly constricted between 

 the seeds. Flowers rose-coloured. Kunth, mim. p. 2. t. 1. 



Whitish Sensitive-plant. Shrub creeping. 



3 M. SENSITIVA (Lin. spec. 1501.) stem and petioles prickly ; 

 leaflets ovate, acute, clothed with adpressed pili beneath, but 

 glabrous above. Jj . S. Native of Brazil. Flowers rose-co- 

 loured and tctrandrous, as in the preceding species, however, 

 Linnaeus's plant is said to have pentandrous flowers. Trew. 

 ehr. t. 95. Ker. bot. reg. 25. Lindl. bot. reg. Flowers purple. 

 Leaflets broad, but not so sensible to the touch as those of M. 

 pudlca. 



Sensitive-plant. Fl. April, Sept. Clt. 1648. Sh. 3 to 6 ft. 



4 M. OBTUSIFOLIA (Willd. enum. p. 1047.) stem and petioles 

 prickly ; leaflets dimidiately cordate, ovate, obtuse, glabrous. 

 I? . S. Native of Brazil. Flowers red. Very like M. sensi- 

 tiva, but more prickly and glabrous. 



Blunt-leafletted Sensitive-plant. Fl. June, July. Clt. 1816. 

 Shrub 2 to 4 feet. 



5 M. STRIGOSA (Willd. spec. 4. p. 1030.) branchlets and pe- 

 tioles beset with stiff hairs and prickles; leaflets rather dimidiate, 

 ovate-oblong, acute, strigose on both surfaces ; heads of flowers 

 usually solitary. Tj . S. Native of South America, at the Ori- 

 noco and of Mexico. H. B. et Kunth, nov. gen. amer. 6. p. 248. 

 Flowers purple. Perhaps the same as M, strigosa of Pers, ench. 

 9.. p. 263. 



Strigose Sensitive-plant. Fl. June, Jul. Clt. 1818. Sh. 1 ft. 



6 M. ADH.<E RENS (H. B. et Kunth, nov. gen. amer. 6. p. 249.) 

 branches hairy and prickly ; petioles villous, unarmed ; leaflets 

 dimidiately-obovate, mucronate, clothed above with adpressed 

 pili, and with silky and somewhat strigose hairs beneath ; heads 

 of flowers solitary. fy , S. Native of South America, at the 

 Orinoco. Flowers red. Legume unknown. 



Adhering Sensitive-plant. Shrub 3 to 4 feet. 



7 M. F!ORIBU'NDA (H. B. et Kunth, nov. gen. amer. 6. p. 

 250.) branches and petioles pubescently-pilose and very prickly; 

 leaflets 2-pairs, somewhat dimidiately ovate, acute, clothed with 

 strigose hairs beneath, but glabrous above ; heads of flowers 

 twin or tern. Pj . S. Native of South America, near Cumana, 

 and of Mexico, near Jalapa. Flowers red. 



Far. ft, Willdenonii (D. C. prod. 2. p. 426.) heads of flowers 

 disposed in a terminal panicle. M. floribunda, Willd. spec. 4. 

 p. 1031. M. Willdenowii, Poir. suppl. 1. p. 50. 

 8 



Bundle-Jlowered Sensitive-plant. Fl. June, July. Clt. 1824. 

 Shrub 1 to 1| foot. 



$ 2. Pudicce (pudicus, chaste ; in reference to the sensitive 

 qualities of the leaves). Leaves with 1 or more pairs of pinnae ; 

 when the last is the case, they are disposed in a digitate manner 

 at the top of the common petiole, each pinna bearing many pairs 

 of leaflets, which are about equal in size and shape. Stamens 4, 

 rarely 5. Leaves itsually sensible to the touch. 



8 M. PISTACI.SFOLIA (Willd. spec. 4. p. 1028.) unarmed; 

 leaves with 1 pair of pinnae, each pinna bearing 3 pairs of elliptic, 

 obtuse leaflets, with a gland between the terminal pair. Tj . S. 

 Native of Caraccas. Flowers red. Legume linear, sinuated, 6-7 

 inches long. Perhaps belonging to a different division of the 

 genus. 



Pistachio-leaved Humble-plant. Tree 10 to 15 feet. 



9 M. VIVA (Lin. spec. 1500.) plant unarmed, herbaceous; 

 leaves with 1 pair of pinnae, each pinna bearing 4 pairs of roundish 

 leaflets; legume with only one joint. l/.S. Native of Jamaica, 

 in meadows. Sloan, hist. 2. t. 182. f. 7. Flowers purple. 



Lively Humble-plant. Fl. July, Aug. Clt. 1739. PI. 1 ft. 



10 M. PECTINA'TA (Kunth, mim. p. 5. t. 2. nov. gen. amer. 6. 

 p. 25.) branches prickly, and beset with stiff villi ; leaves con- 

 jugately pinnate ; common petiole rather shorter than the prickles ; 

 leaflets many pairs, approximate, linear, acute, with strigosely 

 ciliated margins. Jj . S. Native of the Andes of Quito, in 

 hot places. Flowers red. Fruit unknown. 



Pectinate-leaved Humble-plant, Shrub. 



11 M. POLYCA'RPA (Kunth, mim. p. 8. t. 3. nov. gen. amer. 6. 

 p. 25.) branches prickly, striated, pilose ; leaves conjugately 

 pinnate ; petioles much longer than the prickles ; leaflets many 

 pairs, oblong-linear, acute, glabrous above, but clothed with 

 adpressed pili beneath as well as on the margins. fj . S. Na- 

 tive of Peru, in sandy places. Heads of flowers solitary. 

 Flowers red. Legumes pilose, with very hispid margins. 



Many-fruited Humble-plant. Shrub 1 to 2 feet. 



12 M. PUDI'CA (Lin. spec. 1501.) stem herbaceous, prickly, 

 with the petioles and peduncles more or less beset with stiff hairs 

 or bristles ; leaves somewhat digitately pinnate, with 4 pinnae, 

 each pinna bearing many pairs of linear leaflets. O- S. Native 

 of Brazil. Andr. bot. rep. t. 544. Flowers red. Legumes gla- 

 brous in the middle, but with the margins beset with stiff bristles. 

 Superior leaves sometimes the same as the inferior ones. This 

 plant is commonly grown in gardens, under the name of the 

 sensitive plant, the leaves falling on the slightest touch. Sen- 

 sitive plants were not unknown to the ancients. Theophrastus 

 speaks of the Aur-^wo/itrr), as growing about Memphis in Egypt, 

 and Pliny of the JEschynomcne, so called from its contracting 

 the leaves at the approach of the hand. It is thus characterized 

 in the flowery poetry of Darwin : 



" Weak with nice sense the chaste Mimosa stands, 

 From each rude touch withdraws her timid hands ; 

 Oft as light clouds o'erpass the summer glade, 

 Alarm'd she trembles at the moving shade, 

 And feels alive through all her tender form 

 The whisper'd murmurs of the gathering storm ; 

 Shuts her sweet eye-lids to approaching night, 

 And hails with freshen'd charms the rising light." 



The cause of the well-known motion of the leaves of the sensi-' 

 live and humble plants has been the subject of many ingenious 

 explanations ; but it has not been treated by any botanist with 

 so much ingenuity as by Dr. Dutrochet, whose theory we give as 

 explained in the Botanical Register. 



M. Dutrochet states, that having ascertained hot nitric acid 

 to possess the power of separating and reducing to its simplest 



