Question: Which is a member of the Orchid family, Arachnis or Sumac?

Context articles: Arachnis (plant)
Pterostylis recurva
Sumac
Caladenia richardsiorum
Caladenia lowanensis
Caladenia rosella
Caladenia longicauda subsp. extrema
Cryptostylis
Caladenia flavovirens
Caladenia venusta

The genus Arachnis, abbreviated as Arach in horticultural trade, (scorpion orchid,) is a member of the Orchid family (Orchidaceae), consisting of more than 20 species native to China, India, Southeast Asia, Indonesia, the Philippines, New Guinea, and the Solomon Islands.
Pterostylis recurva commonly known as the jug orchid, recurved shell orchid, antelope orchid or bull orchid, is a plant in the orchid family Orchidaceae and is endemic to the south-west of Western Australia.
 It is a relatively common orchid which has up to four jug-shaped or funnel-shaped white flowers with green and brown lines and markings.
 Non-flowering plants have a rosette of leaves on a short stalk.
Sumac (Assyrian Neo-Aramaic: ܣܘܼܡܵܩܵܐ‎ "summāqāʾ" ("red, red shift, turning red"), Arabic: سمّاق‎ ‎ "summāq"; , or ; also spelled sumach, sumaq) is any one of about 35 species of flowering plants in the genus Rhus and related genera, in the family Anacardiaceae.
 The dried and powdered fruits are used as a spice in Middle Eastern cuisine.
 Sumacs grow in subtropical and temperate regions throughout the world, especially in East Asia, Africa and North America.
Caladenia richardsiorum, commonly known as the little dip spider orchid, Richards' spider orchid or robe spider orchid, is a plant in the orchid family Orchidaceae and is endemic to South Australia.
 It is a ground orchid with a single erect, hairy leaf and usually only one yellowish-green flower.
 It is similar to the endangered Mellblom's spider orchid ("Caladenia hastata") but has a much larger leaf and the petals lack glandular tips.
Caladenia lowanensis, commonly known as Wimmera spider orchid is a plant in the orchid family Orchidaceae and is endemic to Victoria.
 It is a ground orchid with a single leaf and a single cream-coloured flower with red lines and blotches.
 The total population of this orchid was estimated in 2010 to be only about 700 plants but most are protected in reserves.
Caladenia rosella, commonly known as the rosella spider orchid is a plant in the orchid family Orchidaceae and is endemic to south-eastern Australia.
 It is a ground orchid with a single hairy leaf and a single scented pink flower.
 Although it may have had a wider distribution in the past, the total number of plants in 2000 was estimated to be 120 in four populations in Victoria.
 There is a single record from New South Wales but the orchid is classified as "extinct" in that state.
Caladenia longicauda" subsp.
 "extrema, commonly known as the late white spider orchid or Seaton Ross spider orchid is a plant in the orchid family Orchidaceae and is endemic to the south-west of Western Australia.
 It has a single hairy leaf and one or two mainly white flowers with long, mostly spreading lateral sepals and petals.
 It is a relatively rare orchid which is similar to the tangled white spider orchid (subspecies "redacta") but has larger flowers and a later flowering period.
Cryptostylis, commonly known as the tongue orchid, is a genus of flowering plants from the orchid family, Orchidaceae.
 It was first defined by the prolific Scottish botanist, Robert Brown in 1810.
 The type species has since been designated as "Cryptostylis erecta".
 Other species include "Cryptostylis hunteriana" and "Cryptostylis subulata".
 Molecular study of their DNA shows the genus lies within the tribe Diurideae within the orchid family, having previously considered part of the Cranichideae.
 Together with the genus "Coilochilus" (endemic to New Caledonia), they make up the subtribe Cryptostylidinae.
Caladenia flavovirens, commonly known as the summer spider orchid, or the Christmas spider orchid is a plant in the orchid family Orchidaceae and is endemic to Victoria in Australia.
 It is a ground orchid with a single hairy leaf and one or two pale greenish-yellow flowers.
Caladenia venusta, commonly known as the graceful spider orchid, large white spider orchid, or simply white spider orchid is a plant in the orchid family Orchidaceae and is endemic to southern Australia.
 It is a ground orchid with a single leaf and one or two white to cream-coloured flowers with drooping, brown, thread-like tips.