no 



ANGIOSPERMAE—DICOTYLEDONES 



584. Hockinia Gardn. 



1922. H. montana Gardn. (Gilg, Ber. D. bot. Ges., Berlin, xiii, 1895.)— Gilg 

 describes the flowers of this species as pleomorphous. Knoblauch (op. cit., xiii, 

 1895) refers all Gilg's forms to two only, so that it is only a case of dimorphism. 



585. Halenia Borckh. 



1923. H. Rothrockii A. Gray. (Gilg, op. cit.) — Gilg states that this species 

 bears cleistogamous flowers of two kinds, in addition to the chasmogamous ones. 



1924. H. multiflora Benth., and 1925. H. parviflora G. Don (=Exadenus 

 viridiflorus Benih). — The relations are similar to those found in H. Rothrockii. 



1926. H. elliptica D. Don ; 1927. H. sibirica Borckh. ; 1928. H. Perrottetii 

 Griseb. ; 1929. H. deflexa Griseb. ; 1930. H. Schiedeana Griseb. ; 1931. H. 

 brevicornis G. Don; and 1932. H. Pavoniana G. Don. ( = H. asclepiadea 

 Griseb.). — Gilg (op. cit.) found cleistogamous flowers in all these species. 



LXIX. ORDER POLEMONIACEAE LINDL. 



Literature. — A. Peter, ' Polemoniaceae,' in Engler and Prand's 'D. nat. 

 Pflanzenfam.,' IV, 3 a, p. 43. 



586. Polemonium L. 



Flowers vary from class C to class Hb. Nectar secreted at the base of the 

 ovary. Occasional gynomonoecism. 



1933. P. caeruleum L. (Sprengel, 'Entd. Geh.,' p. 109 ; Axell, 'Om Anord. 



for Fanerog. Vaxt. Be- 

 frukt.,' p. 33 ; Herm. 

 Muller, ' Alpenblumen,' 

 pp. 257-9, ' Weit. Beob.,' 

 Ill, pp. 8-9; Kerner, 

 'Nat. Hist. PI.,' Eng. 

 Ed. I, II, p. 175; Knuth, 

 ' Bloemenbiol. Bijdra- 

 gen.') — In this species 

 about twenty blue or 

 white flowers, 30 mm. or 

 more in diameter, are 

 borne in a terminal panicle, so that the plant is conspicuous from a distance. 

 In garden plants examined by me at Kiel streaks in the base of the flower serve 

 as nectar-guides, but these would not appear to be constant, for Hermann Muller 

 only figures the whitish base of the corolla as serving this purpose in flowers 

 cultivated at Lippstadt. 



Nectar is secreted at the base of the ovary by a green, fleshy, annular swelling 

 with a wavy edge. It is stored up in the corolla-tube (about 2 mm. deep), and 

 this is closed by woolly hairs, so that only the more intelligent guests, such as 



Fig. 207. PoUmoninnt caerideii-m, L. (from nature). A. Flower in the 

 first (male) stage, seen directly from tfie front. B. Do., in the second 

 (hermaphrodite) stage, seen as before, a. anthers; J, stigmas. 



