Groups The family currently comprises 530 species and 31 genera.
Status
References Vieira and Souza, 2008; Sharma and Bhattaharyya, 1958
Plant Cyperus esculentus
Taxonomic position
― Earlier classification The first study of the infraspecific taxonomy of Yellow Nutsedge was done by Boeckeler who reduced two American species, C. phymatodes H.L. Mi.ihl. and C. lutescens Torr. & Hook. to C. esculentus var. leptostachyus Boeckeler and var. macrostachyus Boeckeler, respectively. Moreover, he recognized a cultivated taxon, C. esculentus var. sativus Boeck. (known as earth almond, tiger nuts or chufa), which is distinguished by its large edible tubers.
― Present classification Ascherson and Graebner divided the species in 2 races: the edible, cultivated sativus, and aureus, including all wild and weedy material. De Vries proposed cv. Chufa for the cultivated taxon.
― Close alliance plants/Origin taxa
Infraspecific classification In a preliminary report on the infraspecific variation of C. esculentus in the Netherlands, Ter Borg described 4 biotypes (A — D), including data on vegetative characters.
Groups In an extensive revision of Cyperaceae, Kiikenthal reviewed the varieties mentioned and described two more, var. nervosostriatus (Turrill) Kiik. (= C. nervosostriatus Turrill) and var. cyclolepis Boeck. ex Kiik.
Status Problems in and indicated several inconsistencies exist. Difficulties establishing the taxonomic position of their material. Cluster study done on paper correlate fairly well with taxa distinguished by Kiikenthal, who recognized them at the level of varieties.
References Schippers et al., 1995
Plant Metroxylon spp
Taxonomic position
― Earlier classification In the early 1970s, Harold E. Moore, Jr., collected two groups of specimens from Samoa that he had identified as Metroxylon warburgii and M. upoluense Beccari
― Present classification Order Arecales, family Palmae, and subfamily Calamoideae. There are two recognized species of Metroxylon according to Beccari (1918): M. sagu without spines and M. rumphii with spines. Presently accepted taxonomy of Rauwerdink who merged the two species into M. sagu based on the fact that seeds from spineless palms can produce spiny seedlings.
― Close alliance plants/Origin taxa M. squarrosum Becc., which according to Rauwerdink is conspecific with M. sagu.
Infraspecific classification Schuilling gives an extensive account of local taxonomy and variability. Rauwerdink recognized four forms based on the length of the spines, proposing that spine length is controlled by a 2-allele system. The question is whether morphological markers such as presence of spines and length of spines are correlated with genetic variation, and if these markers can consequently be used in an infraspecific of M. sagu.
Groups Beccari distinguishes 2 groups among the 9 species of Metroxylon. Three of the species designated by him are both hapaxanthic (the bole ends its life by flowering and fruiting) and soboliferous (the plant tillers or suckers), i.e. sagu, rumphii and squarrosum. Rauwerdink’s, the genus contains only 5 species
Status The taxonomy of the section Coelococcus of the genus Metroxylon was recently revised by McClatchey and a new species described. McClatchey’s findings should be tested using independent molecular evidence.
References Kjaer et al., 2004; McClatchey, 1998, Flach, 1997
Plant Oxalis tuberosa
Taxonomic position
― Earlier classification
― Present classification Oxalis tuberosa belongs to the Oxalidaceae family, which includes 8 genera. The genus Oxalis includes >800 species.
― Close alliance plants/Origin taxa The wild progenitor of domesticated oca is unknown, as is the origin(s) of polyploidy.
Infraspecific classification The most recent monographic treatment of the entire genus is that of Knuth (1930).
Groups Oxalis is a large genus of >800 species, The species of the “O. tuberosa alliance” described by de Azkue and Martınez (1990) (footnote i, Table 1) belong to 4 of Knuth’s sections: Ortgieseae, Carnosae, Clematodes, and Herrerea (Knuth, 1930, 1935, 1936).
Status The many conflicting determinations of specimens in herbaria (E. Emshwiller, personal observations) indicate the need for basic work on species delimitation. This lack makes identification of specimens difficult, meaning identities of plants for which there are published chromosome counts uncertain, and has also complicated both sampling and interpretation of results of this study. Bru’her’s comment that the systematics of genus Oxalis is still at its beginning remains very much true today.
References Malice, 2009; Emshwiller and Doyle, 1998
Plant Ullucus tuberosus
Taxonomic position
― Earlier classification Moquin-Tandon described the genera in family Basellaceae.
― Present classification The genus Ullucus of the family Basellaceae is Monospecific.
― Close alliance plants/Origin taxa Tournonia forms sister taxa.
Infraspecific classification Ullucus tuberosus comprises 2 subspecies: aborigineus and tuberosus. Cultivated ulluco belongs to the sub-species tuberosus, and is cultivated for its edible tubers.
Groups Two subspecies of Ullucus are aborigineus (stolons along entire shoot) and tuberosus (stolon at base).
Status Unresolved and uncertain relationships with other species of the family.
References Eriksson, 2007
Plant Pachyrhizus erosus, P. angulatus
Taxonomic position
― Earlier classification First botanical references to the yam bean was made by Plukenet in 1696, who described a plant from Mexico as Phaseolus nevisensis. The present generic name Pachyrhizus was originally used by L.C.M. Richard. Pachyrhizus is delimited by the short hairs on the adaxial side of the ovary extending almost to the stigma, forming a “beard” along the incurved style and by the median to subterminal globular process on the adaxial side of the stigma.