Family 6. BALSAMINACEAE 



By Per Axel Rydberg 



Annual or perennial, caulescent or acaulescent herbs. Stem or peduncle 

 usually succulent, turgescent, semitranslucent, often swollen at the nodes. 

 Leaves simple, thin, feather- veined, usually toothed, usually petioled and 

 without stipules. Flowers racemose, or solitary or geminate in the axils of 

 the leaves, perfect, sometimes of two kinds. The normal flowers strongly 

 zygom orphic. Sepals 3, rarely 5, imbricate ; the posterior one petaloid, 

 strongly saccate, conic, helmet-shaped, horn-like or boot-shaped, usually pro- 

 duced into a spur. Petals 5, or by union of two and two (the lateral and pos- 

 terior) only 3, of various shape. Stamens 5, alternate with the petals; fila- 

 ments usually short and inverted-subulate, distinct ; anthers short, thick, 

 united around the stigmas. Gynoecium of five united carpels ; style very short 

 or almost none ; stigmas 5, sometimes wholly united. Ovules 2-many in each 

 locule, inserted in the inner angles. Seeds pendulous, anatropous, with dorsal 

 rhaphe, without endosperm. The cleistogamous flowers, if present, smaller, 

 more regular, and more fertile. 



1. IMPATIENS L. Sp. PI. 937. 1753. 



Bahamina Gaertn. Fruct. 2: 151. 1790. 



All our species annual. Sepals in ours 3, the anterior ones lacking (whenever these 

 are present in exotic species the}' are always reduced). Lateral petals each united with the 

 adjacent posterior one. Capsule elastically dehiscent. Seeds usually many, pendulous 

 above each other in a single row. 



Type species, Impatiens Noli-tangere L. 



Flowers racemose ; pod splitting from the base upwards into spirally twisted 

 valves (in /. turrialbana unknown). 

 Leaves alternate ; flowers yellow or orange. 

 Spur present. 



Spur porrect, i. e., bent at a right angle to the sac, one fourth as long as 

 the same or less ; sac as broad as long, pale-yellow, unspotted or 

 minutely so. l. /. pallida. 



Spur strongly incurved, one third as long as the sac or more ; sac longer 

 than broad. 

 Sac at least two thirds as broad as long, abruptly contracted into the 

 spur ; flowers orange or pinkish, with large spots or rarely un- 

 spotted. 2. /. biflora. 

 Sac one half as broad as long or less, gradually tapering into the 

 spur. 

 Flowers unspotted ; sac 2 cm. long or less. 



Sac about 2 cm. long ; flowers light-yellow. 3. /. occidentalis. 



Sac about 12 mm. long ; flowers golden-yellow. 4. /. aurella. 



Flowers spotted ; sac over 2 cm. long. 



Bracts linear-lanceolate, 5 mm. long; anterior petal nearly 1 



cm. long. 6. /. Nortonii. 



Bracts subulate, minute ; anterior petal about 5 mm. long. 7. /. mexicana. 



Spur wanting. 5. /. ecalearata. 



Leaves opposite ; flowers purple. 8. I. turrialbana. 



Flowers single on the peduncles, solitary or geminate in the axils of the leaves ; 

 pods splitting from the apex into incurved, not twisted, valves ; flowers purple. 9. 1. Bahamina. 



1. Impatiens pallida Nutt. Gen. 1 : 146. 1818. 



Impatiens Noli-tangere Michx. Fl. Bor. Am. 2: 149. 1803. Not /. Noli-tangere L. 1753. 

 Impatiens aurea S. Wats. Bibl. Ind. 152, as a synonvm. 1878. Not/, aurea Muhl. 1813. 

 Impatiens pallida alba Clute, Am. Bot. 7 : 67. 1904. 



Volume 25, Part 2, 1910] 93 



