SYSTEMATIC POSITION OF M1THASTEMON. 201 



whether the said characters necessarily prevent it from being taken into the 

 same family, or in other words whether the differences are such as separate 

 genus from genus or family from family. 



So far as I am aware, a discussion of this kind 011 Mitrastemon has 

 never been undertaken. Moreover, there is no work on the anatomy of the 

 intramatrical tissue, the flower-peduncle, or the structure of the ovules, 

 which collectively make up a group of characters which are as important as 

 any other floral characters for the determination of a systematic position. 

 In this paper, I shall first consider the morphology of the plant both external 

 and internal, especially so far as is necessary for the present descussion 

 and then in its bearings on the systematic position of the plant itself. 



n. External Morphology of Mitrastemon, especially with 

 regard to its systematic Position. 



*The plants are leafless, uubranching, single flowered parasites growing 

 on exposed roots of Quercus cuspid dn. Roots over 1 cm. in diameter frequent- 

 ly bear numbers of these plants. The volva is always in colony, separate, 

 or confluent below, short, globose, erect, sessile, dark fulvous. Peduncles 

 simple, thick, straight or sometimes slightly curved, terete or subcompressed- 

 ly terete, smooth on surface, provided with scales. Scales opposite in 5 or 

 6 pairs, imbricate, decussate, concave, margin adnate to the peduncles at the 

 base, forming tubes in the basal portions, where honey -like fluids are secret- 

 ed in abundance.** Scales are more or less shining owing to a small quanti- 

 ty of a fluid secreted on the surface, especially when the flowers are in bloom. 

 Flowers are always hermaphrodite and usually regular, but sometimes more 

 or less diclinous, especially in the ealier stage of flower-development. Of 

 the four primordial leaves which compose the perianth, the front and back 

 ones are usually broader than the lateral pair. In many cases, they, in a 



* The reader is requested to refer to the original description of Mitrastemon Yamamotoi MK. 

 <xmtributed by Mr. T. MAKIXO to the Tokyo Bot. Mag. XXV. p. 252, T. VII. and M. Kawasa- 

 sakil HAY. in the same journal, XXVI. p. 112. 



** In the flowering season, this honey attracts large numbers of a bird resembling a Japanese 

 white eye, (Zosterops juponica T. et Z.). 



