Angiosp : Dicot : Polypet : Thalamif] : Cistiflorae, I. III. 



CISTIFLORAE in the wider sense conveniently include a vast range of types 

 in which the fully petaloid flower attains a normal pentamerous calyx and an appar- 

 ently whorled corolla ; the androecium remains wholly indefinite, but the gynoecium 

 becomes syncarpous, either by a gamocarpous zone to constitute a new unilocular 

 ovary-chamber with parietal placcntation, or by pocket-formations to a plurilocular 

 condition with placentation axile, or ultimately basal. The carpels remain vestigial 

 as mere stigmatic lobes, or may be wholly lost. Forms with unilocular ovary and 

 parietal placentation may be conveniently taken first (cf. Cohort Parietales, Gen. 

 Plant., 1862). 



In N. Temp, flora the series is commonly approached by the small group of 

 Cistaceae (4/160) on which it was originally founded, based on the Mediterranean 

 forms of Cistiis ; and again from the specialized families of the Rhoeadineae, more 

 particularly as familiar in the special limiting cases of the Crucifer and Poppy. 



The alternative line of progression with axile placentation, familiar in Hypeii- 

 caceae, may be extended to the great tree-families of Gutiiferae, Ternstroemiaceae, 

 Dipterocarpaceae. 



The Malvales alliance may be considered separately. Probably the oldest phase 

 of the progression is to be traced in Dilleniaceae which remain predominantly apo- 

 carpous, and hence come at an early stage in older classifications \Gen. Plant., 1862). 



I. The Dilleniaceae (11/300), commemorating Dillenius, professor at Oxford, 

 1734-47, founded 1818, based on the remarkable type : — 



Dillenia indiea, a middle-sized tree of moist regions, cult., with large evergreen 

 serrated foliage-leaves, and fine solitary white flowers, 6-10 in. diam. ; sepals quin- 

 cuncial, thick and fleshy; petals 5, flimsy and fugitive ; stamens indef., all alike and 

 inarching; carpels in a single cycle, 15-20, fused along the massive conoidal recep- 

 tacle, but free laterally, essentially apocarpous, w^ith many ovules. The free white 

 styles are linear and recurve over the golden-yellow androeciuin. 



In fruit the gynoecium enlarges with the growth of the seeds (8 mm.) with little 

 change ; the massive sepals close over the carpels to give a succulent acid mass, 

 4-6 in. diam., and more than i in. thick over the enclosed carpels and seeds. Float- 

 ing on water, eaten by elephants, but essentially for xerophytic protection of seeds on 

 ground in hot season ; seeds in protective mucilage ; germination on the ground in 

 situ, assisted by ants. 



D. peutagyna, a small tree of deciduous forest, 60-70 ft. ; foliage-leaves 2-4 ft. 

 Flowering in March, April, before the leaves : flowers yellow, i in. diam., in clusters 

 from tuberous spurs on the older wood ; reduced in number of parts ; androecium of 

 indef. outer stamens, erect and extrorse, with inner series of 10 recurved anthers on 

 longer filaments. Gynoeciuin of 5 (6) carpels, free laterally, on a steeply conical 

 receptacle, ovules numerous ; styles free, long and reflexed over androecium. Fruit 

 with persistent sepals, i in., orange-yellow, taken by birds, similarly enclosing soft 

 jpdehiscent carpels, each maturing i seed. 



CL D. scabrella, \txy similar, flowers i-j in. diam.; androecium of about 100 

 stamens, outer series 90, inner 10-12 reflexed over preceding; gynoecium of 5-6 

 carpels, free laterally, but cutting in transverse section as if with axile placentation 

 owing to elongation of receptacle. Flowers give pollen only and are nototribal to 

 insects crawling over the lower extrorse anthers. 



II. Bixaceae (4/20) a smaH order separated from Cistaceae by the leaves being 

 spirally arranged instead of decussate, based on the monotype — 



Bixa Orellana, a shrub, indig. to Central America and cult. (Arnatto). Flowers 

 1-2 in. diam., white or pink, of generalized Cistifloral habit. Petals flmis)-, i in. ; 

 stamens 200-300, with slender filaments as tassel-cluster, on a distinct collar-zone 

 around the ovary. Gynoecium syncarpous, of 2 median carpels ; the ovary, 3 mm., 

 covered with emergences ; style stout, 13 mm., ovules many, on 2 parietal placentas. 



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