Question: Which flower has the greatest number of recognized species, Barkeria or Arum?

Context paragraphs:
Arum: Arum is a genus of flowering plants in the family Araceae, native to Europe, northern Africa, and western and central Asia, with the highest species diversity in the Mediterranean region.  Frequently called "arum lilies", they are not closely related to the true lilies "Lilium".  Plants in closely related "Zantedeschia" are also called "arum lilies".

Placonotus: Placonotus is a genus of beetles in the family Laemophloeidae.  There are 40 currently recognized species, known from all continents except Antarctica.  "Placonotus" species are small (~2mm), elongate, flattened beetles, characterized by long filiform antennae, presence of a frontoclypeal suture, open anterior coxal cavities, and broadly rounded intercoxal process of abdominal ventrite III.  Males have the 8th abdominal segment modified to form claspers used during mating.  Adults and larvae are found under dead bark, where they feed on fungi.  Currently recognized species are:

Sea cucumber: They are marine animals with a leathery skin and an elongated body containing a single, branched gonad.  Sea cucumbers are found on the sea floor worldwide.  The number of holothurian ( ) species worldwide is about 1,717 with the greatest number being in the Asia Pacific region.  Many of these are gathered for human consumption and some species are cultivated in aquaculture systems.  The harvested product is variously referred to as "trepang", "bêche-de-mer" or "balate".  Sea cucumbers serve a useful role in the marine ecosystem as they help recycle nutrients, breaking down detritus and other organic matter after which bacteria can continue the degradation process.

Heleomyzidae: The Heleomyzidae are a small family of true flies in the insect order Diptera.  Over 740 described species of Heleomyzidae occur in about 76 genera and 22 tribes distributed throughout the world; the greatest number occur in the Holarctic region.  Around 100 species of Heleomyzidae are found in North America.  Larvae feed on decaying plant and animal matter, mushrooms, and various fungi.  Most of the subfamilies have been commonly recognized as families in the past, but are now included within the Heleomyzidae.  The composition and monophyly of the family continues to be controversial.  McAlpine recently combined Heleomyzidae and Sphaeroceridae into Heteromyzidae, but this arrangement has not been widely accepted.

Alismataceae: The water-plantains (Alismataceae) are a family of flowering plants, comprising 11 genera and between 85 and 95 species.  The family has a cosmopolitan distribution, with the greatest number of species in temperate regions of the Northern Hemisphere.  Most of the species are herbaceous aquatic plants growing in marshes and ponds.

Barkeria: Barkeria, abbreviated Bark in horticultural trade, is a genus of orchids.  It consists of about 17 currently recognized (May 2014) species native to Mexico and Central America.  This genus was once considered part of "Epidendrum".  Type species is "Barkeria elegans"; this is now considered a synonym of "B. uniflora" yet retains its status as type per ICN.

File sharing in Canada: File sharing in Canada relates to the distribution of digital media in that country.  Canada had the greatest number of file sharers by percentage of population in the world according to a 2004 report by the OECD.  In 2009 however it was found that Canada had only the tenth greatest number of copyright infringements in the world according to a report by BayTSP, a U.S. anti-piracy company.

Honeyguide: Honeyguides (family Indicatoridae) are near passerine bird species of the order Piciformes.  They are also known as indicator birds, or honey birds, although the latter term is also used more narrowly to refer to species of the genus "Prodotiscus".  They have an Old World tropical distribution, with the greatest number of species in Africa and two in Asia.  These birds are best known for their interaction with humans.  Honeyguides are noted and named for one or two species that will deliberately lead humans (but, contrary to popular claims, not honey badgers) directly to bee colonies, so that they can feast on the grubs and beeswax that are left behind.

Western diamondback rattlesnake: The western diamondback rattlesnake or Texas diamond-back ("Crotalus atrox") is a venomous rattlesnake species found in the southwestern United States and Mexico.  It is likely responsible for the majority of snakebite fatalities in northern Mexico and the greatest number of snakebites in the U.S. No subspecies is currently recognized.

Quinault Rainforest: The Quinault Rain Forest is a temperate rain forest, which is part of the Olympic National Park and the Olympic National Forest in the U.S. state of Washington in Grays Harbor County and Jefferson County.  The rain forest is located in the valley formed by the Quinault River and Lake Quinault.  The valley is called the "Valley of the Rain Forest Giants" because of the number of record size tree species located there.  The largest specimens of Western Red Cedar, Sitka Spruce, Western Hemlock, Alaskan Cedar and Mountain Hemlock are found in the forest as well as five of the ten largest Douglas-firs.  The forest receives an average of 12 feet of rain per year.  It is believed to be the area with the greatest number of record size giant tree species in the smallest area in the world.  It does have the largest trees in the world outside of the state of California and New Zealand.

Supporting paragraphs: Barkeria Arum
Answer: Arum