Writing in June, 1938, issue of Australian Orchid Review, the Rev. Rupp described the find: "The most remarkable orchid discovered in N.S.W. ... hails from Bulahdelah, and has not so far been recorded elsewhere.  This is not surprising, for the whole plant is subterranean.

It was found "accidentally" by Mr. E.W. Slater in 1931.  I shall always count myself exceptionally fortunate that the first specimen of this extraordinary orchid was sent to me.  Mr. Slater enclosed it as a curiosity, with some roots of Dipodium sent to Mr. F.J. Fieldsend of Maitland, and Mr. Fieldsend promptly forwarded it to me.

"Though clearly belonging to the new Orchidaceous sub-tribe which Dr. Rogers had to create for [the western Australian species] Rhizanthella [gardneri], the Bulahdelah plant would not fit into that genus, and I gave it the name Cryptanthemis slateri."

"Subsequently a grant from the Australian and New Zealand Association for the Advancement of Science enabled me to pay a visit to Bulahdelah, where, with the help of Dr. H.L. Kesteven, six plants were unearthed, and photographs were secured in situ after 'excavation'.  Shall we ever trace the causes which impelled this orchid to its underground career?"  

"In a second paper presented to the Linnean Society the Rev. Rupp described his own uncovering of Cryptanthemis slateri, with the help of Dr. H.L. Kesteven, in the vicinity of the original finding.

He describes it: "The site of the discovery of Cryptanthemis slateri is a small and obscure water channel, dry except during rain, when it discharges into a shallow gully a few yards on the south side of the old Alum Company's trolley line near the Alum dump - on the lower western slope of the Alum Mountain and  ,,, about 250 feet above sea level.  All plants of the orchid hitherto found - in number perhaps 12, but in view of the fragmentary character of the 1931-32 specimens it is difficult to be sure - have been located within a radius of about eight yards of this spot ... the ground is very stony and there is little grass or undergrowth.  It is a barren spot occupied chiefly by stringybark eucalypts, under which are carpets of fallen leaves and other debris.  The lack of undergrowth serves to make conspicuous the numerous plants of Dipodium punctatum R. Br  which are found here.

"Dr. Kesteven and myself demonstrated beyond question, not only the validity of Cryptanthemis slateri, but the fact that there is no real association between it and Dipodium punctatum at all ... we consider it likely that the mycorrhiza infesting both might be found to be identical ... .  "... all the withered flower heads were just level with the surface underneath the debris of fallen leaves, etc. ... .  One may assume that the purpose of this is to facilitate the dispersion of seed by bringing the fruiting capilula to the surface.  It is difficult to see how dispersion is effected except by rainfall.  In spite of the fact that large quantities of seeds are produced and ripened, the apparent scarcity of the plant suggests that successful germination is rare. "

The above extracts are from The Australian Orchid Review, June, 1981 by Mr. Ronald Kerr.

The Bulahdelah district held the high water mark of Rev Rupp's botanical activities, for in eighteen months Rev. Rupp had collected over 700 species of flowering plants and ferns (with very little attention to grasses and sedges).

'A botanist's paradise' is a term apt to become threadworn, and Rev. Rupp has used it before in his recollections: therefore he was almost diposed to class Bulahdelah as the botanist's seventh heaven.

The Rev. Herman Montague Rucker Rupp recorded eighty-nine species of orchids from this district (inclusive of a few not collected by himself but sent to him for indentification, and excluding two or three doubtful forms).

Among these orchids is one constituting in itself a new genus and species - which may fairly claim to be the most remarkable orchid hitherto found in New South Wales, and which the Rev. Rupp had the privilege of describing and naming as Cryptanthemis slateri - the former ('hidden flower') in allusion to its habit, and the latter in honour of its discoverer.

Including two Cymbidiums, 22 of the Bulahdelah orchids are epiphytes, the remaining 67 being dwellers upon earth.  On the Alum Mountain itself 58 of the total 89 orchids have been recorded.  One of these, a tiny Helmet Orchid, puzzled even the redoubtable Dr. Rogers when I sent him specimens; but ultimately he found that it had been discovered and named by Allan Cunningham in 1833, and thereafter lost sight of for ninety-one years!  It has since turned up on Russel Island in Moreton Bay.