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MEMOIRS. OF THE NEW YORK BOTANICAL GARDEN 



[VOL. 10 



Achlyphila. 



The venation of the flower of Achlyphila is relatively simple in comparison 

 with that of Abolboda. Fewer levels therefore suffice to show the principal 

 features, and are shown in figures 82-87. The pedicel, illustrated in figure 82, 

 contains two circles of bundles. The outermost of these circles departs into the 

 bases of the three sepals (fig. 83), in such a way that five traces are present in 

 each sepal (fig. 84). Successive levels (figs. 84, 85) illustrate that above the 

 level of sepal departure, the three whorls — petals, stamens, and uynoecium — 

 become separate at approximately the same point. As in Abolboda, the stamen 

 traces branch from the vein which can be demarcated as the midvein of each 

 petal. No traces indicate any vestige of three other stamens, or of staminodia, 

 which might be assumed to have been present primitively. About five traces 

 are present in each petal, although these probably originate from about three 

 traces in each petal base. The venation of the ovary is identical to that of 

 Abolboda, as a higher level (fig. 86) indicates. As in Abolboda, widening of the 

 petals is concomitant with branching of veins. Ridges, which fit into interstices 

 between the sepals, were observed on the abaxial surface of the petals, and 

 presence of these ridges alters the appearance of petal vascularization somewhat, 

 for these ridges are vascularized. The venation of the style is as in Abolboda, 

 except that no branching of the three veins takes place, as no appendages are 

 present. 



The similarities between Abolboda (e.g., A. linearifolia) and Achlyphila in 

 respect to floral venation are quite striking. The only major differences are in 

 the relative levels at which veins depart. Staminodia and ovary appendages 

 are absent in Achlyphila, and three, rather than two, sepals are present (although 

 some species of Abolboda also have three sepals). 



FLORAL HISTOLOGY 



Certain details of floral anatomy other than venation are worthy of descrip- 

 tion here because of their importance in suggesting specific and generic relation- 

 ships. Some of these have been mentioned in connection wth sepal structure. 



Corolla Lobe. 



Corolla lobes, as might be expected, are thicker in their central portion than 

 at their margins. The maximum width of corolla lobes was found to offer a 

 convenient point of comparison. The corolla lobe of Abolboda linearifolia (fig. 

 92), like those of the other species of Abolboda, has a maximum width of ap- 

 proximately four mesophyll cells. The maximum mesophyll width in corolla 

 lobes of Orectanthe sceptrum subsp. occidentalis (fig. 91) proved to be about 

 10 cell layers; these cells are much larger than those of Abolboda. In Achlyphila 

 disticha, the maximum width (excluding ridges) appeared to be about 8 layers, 

 as shown in figure 93, with a lignified sheath around veins. 



Figs. 88-90. Portions of transections of anthers. Fig. 88. Abolboda linearifolia. Fig. 

 89. Orectanthe sceptrum. Fig. 90. Achlyphila disticha. Figs. 91-93. Portions of transections 

 of corolla lobes or petals. Fig. 91. Orectanthe sceptrum. Fig. 92. Abolboda linearifolia. 

 Fig. 93. Achlyphila disticha. Scale for figures 91-93 is shown beside figure 92. All scales are 

 in 1 nun divisions. 



