80 DENDROBIUM. 



aspect, 3 — 4 inches across ; dorsal sepal narrow-subulate, the lateral two 



lanceolate, much broader at the base than the dorsal one, yeUow 



spotted with red ; petals linear, shorter and narrower than the sepals, 



white streaked with red ; lip broadly ovate, apiculate, obscurely three- 



lobed, with two white lameihe between the side lobes that are reduced 



to slender keels on the front lobe, white with transverse red bars. 



Column yellowish. 



Dendrobiuru tetragonum, A. Cunn. Lindl. in Bot. Reg. 1839, misc. 33. Benth. Fl« 

 Austral. VI. p. 279. Bot. Mag. t. 5956.* 



Discovered by Allan Cunningham, about the year 1820, in the 



dry shady woods around Moreton Bay, and subsequently detected 



by other explorers in the neighbourhood of Rockingham Bay, on 



the banks of the Hastings or Macleay River, and in other localities 



near the east coast of Australia. It is one of the most singular 



of Dendrobes, that merits notice on account of its remarkable 



flowers and curious habit. The specific name, literally " four-angled," 



refers to the stems. 



D. thyrsifloruni. 



Eudendrobium — Calostaclujce. Stems terete, erect, 15 — 24 inches 



high, bearing near their apex 5 — 8 oval-oblong, persistent leaves, 4 — 6 



inches long and 2 inches broad. Racemes lateral, pendulous, 9 — 12 



inches long, many-flowered. Flowers 1| — 2 inches across, spirally 



arranged round the rachis ; sepals and petals of semi-transparent texture, 



white, the former ovate-oblong, acute, the latter sub-orbicular with 



denticulate margin ; lip downy with a convolute claw which causes 



the sub-orbicular, fimbriate blade to take the form of a wide-mouthed 



funnel, rich orange-yellow. 



Dendrobiurn thyrsifloruni, Illm. hort. t. 207 (1875). Kegel's Gartenfl. t. 1021. 

 Fl. Mag. n. s. t. 449. D. densiflorura, var. albo-luteum, Bot. Mag. t. 5780. The 

 Garden, XXX. (1886), t. 574. 



var. — Walkerianum. 



Stems longer; racemes longer and bearing larger flowers. 

 D. thyrsifloruni Walkerianum, Warner's Sel. Orch. III. t. 21. 

 It is more on horticultural than on scientific grounds that we 

 give specific rank to this beautiful Dendrobe, as the characters which 

 distinguish it from Dendrobiurn densiflorum, to which it has been 

 referred by Sir J. D. Hooker, are not usually considered by good 

 authorities to be of sufficient value to constitute a species even in 

 the vague sense the term has acquired in Orchidology. Almost 

 the only differences between the two forms are, that in D. thyrsi- 

 fiorum the stems are terete and not angulate ; they are also longer 



* This plate does not do justice to the flowers. 



