ORCHIDACEiE 



8. Thrixspermum Robinsonii sp. nov. Aff. T. Vanoverberghio. 

 Radices fibratag, verrucosa^, elongatas. Caules usque ad 2.5 cm. 

 longi, complanati, foliosi. Folia disticha, non conferta, valde cori- 

 acea, carnosa, in sicco profunde rugosa, 2.5-3.5 cm. longa, 6 mm. 

 lata, ad apicem imequaliter biloba, ad marginem denticulata, 

 oblongi-lanceolata, vaginis persistentibus caulem obtegentibus. 

 Bases foliorum circiter 6 mm. longi. Pedunculi graciles, pauci- 

 bracteati, glabri, usque ad 8 cm. longi. Rhachis inflorescentiaa, 

 incrassatus, bracteis imbricantibus, confertis, triangulari-cymbi- 

 formibus, rigidis, acutis, patentibus, circiter 2 mm. longis. Flores 

 succedanei,membranacea3.Pedicellus cum ovario usque ad 5 mm. 

 longus, gracilis, bracteis multo longior. Sepala lateralia inaequali- 

 ter ovata, 5.5 mm. longa, 4 mm. lata, obtusa. Sepalum dorsale 

 elliptico-lanceolatum, subacutum, 6 mm. longum, 4 mm. latum. 

 Petala simile, 5.5 mm. longa, 3 mm. lata. Labellum breviter 

 unguiculatum, leviter saccatum, a basi trilobatum, lobis asqualis, 

 rotundatis, semi-orbicularibus, sacco obtuso, rotundato, hemi- 

 spherico, antice ad marginem sacci calli duo, complanati, mem- 

 branacei, obtusi, erecti stant, prope medium callus pubescens. 

 Lobus medius labelli pubescens. 



In the structure of the flower Thrixspermum Robinsonii is very 

 similar to T. Vanoverberghii Ames. The vegetative characters, 

 however, are a simple means for distinction. In T. Vanoverberghii 

 the leaves appear to arise more or less from the same place and 

 ascend obliquely, whereas in T. Robinsonii the leaves are dis- 

 tinctly distichous and spread horizontally. The structure of the 

 labellum in both species is similar. Whether or not the vegetative 

 distinctions are constant it is quite impossible to determine from 

 the material I have examined. 



Luzon, Laguna Province, Mount Maquiling, C. B. Robinson Bur. Sci. 

 17096, December 7, 8, 1912. Altitude 900-1000 meters. Flower white 

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