804 



MACROSCOPIC AND MICROSCOPIC CHARACTERS OF PLANTS. 



width of the upper epidermal cells of the leaf at the base 

 9 ; number of stomata at the middle of the leaf on the 

 lower surface $ ; depth of the midrib bundle S on the 

 transverse section of the leaf; depth of the upper scler- 

 enchyma strands 9 , depth 9 , and width 9 = S of the 

 lower sclerenchyma strands in the transverse section of 

 the leaf, halfway between the midrib and the margin; 

 length 9 and width $ of the lower epidermal cells on the 

 anterior lobe of the labellum; length $ of the upper 

 epidermal cells of the lateral lobe of the labellum ; length 

 9 and width 9 of the inner epidermal cells of the label- 

 lum above the band ; length 9 , and width $ , of the inner 

 epidermal cells at the base of the column. (Table J 28.) 



TABLE J 28. Summary of characters of hybrid-stock as regards 

 sameness, intermediateness, excess, and deficit of development in 

 relation to parent-stocks. 



4r. MACEOSCOPIC AND MICROSCOPIC CHARACTERS OF 

 DENEOBIUM FINDLAYANUM, D. NOBILE, AND D. 

 CYBELE. 



(Plate 32, figs. 190 to 195. Tables J, 29 to 42; I, 4 and Summaries, 

 Chart F 4.) 



GENERAL DESCRIPTIONS. 



Data for the following descriptions were obtained 

 from Engler ( Pflauzenreich, iv, Th. 50, n B 21, 30, 35, 

 306), Veitch (Manual of Orchidaceous Plants, i, 43, 63, 

 87) and Sander (Orchid Guide, 70, 73). 



Dendrobium findlayanum Parish and Reichb. f. 

 (Seed Parent). Stems jointed, with yellowish-green, 

 compressed, clavate internodes, slender at the base and 

 very much swollen at the nodes. Leaves ovate lanceolate, 

 obliquely emarginate. Bracts small and triangular. 

 Flowers usually in pairs on pale lilac pedicels from short 

 racemes produced from nodes of non-leafy stems ; sepals 

 oblong lanceolate; lateral ones at their bases prolonged 

 into a short spur ; petals ovate oblong, much broader than 

 the sepals ; sepals and petals white, tipped with magenta- 

 pink; labellum clawed with a broad ovate blade that is 

 convolute ; apex acute, disk sparsely hairy, orange-yellow 

 at the base, white at the rim, magenta-pink at the extreme 

 tip; column white. 



Dendrobium nobile Landl. (Pollen Parent). Stems 

 jointed, only very slightly wider at the nodes. Leaves 

 ovate, lanceolate, obliquely emarginate. Bracts small. 

 Flowers usually in pairs on short racemes from nodes of 

 non-leafy stems; sepals oblong-lanceolate, lateral ones 

 at their bases prolonged into a short obtuse spur ; petals 

 ovate-oblong, wider than the sepals, margin wavy ; sepals 

 and petals white, tipped with pale reddish violet; label- 

 lum clawed with an obovate-oblong blade that is convo- 

 lute, apex acute, hairy above and below, deep magenta 

 at base, yellowish white at rim, pale reddish violet at 

 extreme tip ; column green. 



Dendrobium cybele (Hybrid). Stems jointed with 

 internodes that are slender at the base and slightly swol- 



len at the nodes. Leaves ovate lanceolate, obliquely 

 emarginate. Bracts small. Flowers usually in pairs on 

 short racemes from nodes of non-leafy stems; sepals 

 oblong lanceolate, lateral ones at base produced into a 

 short spur; petals ovate-oblong, broader than sepals, 

 margin faintly wavy; sepals and petals white, tipped 

 with pale reddish violet ; labellum clawed with a broadly 

 ovate blade that is convolute ; apex acute, less hairy than 

 D. nobile, deep reddish violet with a tinge of brown at 

 the base, yellowish white at the rim, pale reddish violet 

 at the extreme tip ; column green. 



COMPARISONS OF THE MACROSCOPIC CHARACTERS. 

 ROOTS. 



Practically identical in both parents and hybrid. 

 Many slender cylindrical roots are given off from the 

 base of the pseudobulbs. 



STEM. 



Stems erect or semipendulous and jointed in all three 

 plants. The joints are smooth, yellowish green, and club- 

 shaped, very slender at the base and swell out at the nodes 

 where they are slightly compressed in D. findlayanum. 

 They are deeply ridged, of a much darker green, and 

 only very slightly thicker at the nodes than at the base 

 in D. nobile. They are intermediate in color and ridged 

 in the hybrid, but in the amount of swelling at the nodes 

 more like D. nobile. The internodes are longer in D. 

 findlayanum than in D. nobile, and they are shorter in 

 the hybrid than in either parent. The narrowest part of 

 the internode is much wider in D. nobile than in D. find- 

 layanum and it is in width intermediate in the hybrid 

 but much nearer D. nobile. Measurements were made at 

 the second, third, and fourth nodes from top of growths 

 of the preceding year. 



TABLE J 29. Length and diameters of internodes and diameters of 

 nodal swellings. 



D. findlayanum: Average length of internode 4.8 cm.; diameter of 



nodal swellings 1.6 cm.; diameter of internodes, narrowest part 



0.4 cm. 

 D. nobile: Average length of internode 3.2 cm.; diameter of nodal 



swellings 1.2 cm.; diameter of internodes, narrowest part 0.9 cm. 

 D. cybele: Average length of internode 2.9 cm.; diameter of nodal 



swellings 1.2 cm.; diameter of internodes, narrowest part 0.8 cm. 



LEAF, 



The leaves arise at the nodes and consist of an ovate 

 lanceolate lamina and a sheathing petiole which is per- 

 sistent. The lamina of D. findlayanum is shorter but 

 wider than in D. nobile. It is shorter in the hybrid than 

 in either parent and of the same width as in D. nobile. 

 The petiole is slightly shorter and much narrower in 

 D. findlayanum than in D. nobile. It is shorter in the 

 hybrid than either parent and though in width between 

 the parents it is much nearer D. nobile than D. find- 

 layanum. The sizes of the laminas and petioles are 

 given in Table J 30. 



TABLE J 30. Sizes of laminas and petioles. 



D. findlayanum: Length of lamina 8.2 cm.; width 2.0 cm.; length of 



petiole 2.5 cm.; width 1.5 cm. 

 D. nobile: Length of lamina 12.1 cm.; width 2.1 cm.; length of petiole 



2.6cm.; width 2.7 cm. 

 D. cybele: Length of lamina 7.1 cm.; width 2.1 cm.; length of petiole 



2.2 cm.; width 2.4 cm. 



