Question: Which type of plant has more species:  Mentha or Calodendrum?

Context paragraphs:
Yerba buena: Yerba buena or hierba buena is the Spanish name for a number of aromatic plants, most of which belong to the mint family.  "Yerba buena" translates as "good herb".  The specific plant species regarded as "yerba buena" varies from region to region, depending on what grows wild in the surrounding landscape, or which species is customarily grown in local gardens.  Perhaps the most common variation of this plant is spearmint ("Mentha spicata").  The term has been (and is currently) used to cover a number of aromatic true mints and mint relatives of the genera "Clinopodium", "Satureja" or "Micromeria".  All plants so named have medicinal properties, and some have culinary value as herbal teas or seasonings as well.

Mentha pulegium: Mentha pulegium, commonly (European) pennyroyal, or pennyrile, also called squaw mint, mosquito plant and pudding grass, is a species of flowering plant in the Lamiaceae family, or mint family, native to Europe, North Africa, and the Middle East.  Crushed pennyroyal leaves emits a very strong fragrance similar to spearmint.  Pennyroyal is a traditional folk remedy, emmenagogue, abortifacient, and culinary herb.  European pennyroyal is related to an American species, Hedeoma pulegioides.  Though they differ in genera, they share similar chemical properties.

Mentha canadensis: Mentha canadensis (syn.  "M. arvensis" var.  "canadensis") is a species of mint commonly known as American wild mint, native to North America (from Northwest Territories to central Mexico), or known as bakha, East Asian wild mint, or Japanese Mint ("M. arvensis" var.  "piperascens") in eastern Asia (Siberia to Java) and the Northern Territory of Australia.  The flowers are bluish or a slight violet tint.  The plant is upright about 4 in to 18 in tall.  Leaves grow opposite from each other, and flower bunches appear at the upper leaf axil.  The mint grows in wet areas but not directly in water, so it will be found near sloughs, lake and river edges.  Flowers bloom from July to August.

Calodendrum: Calodendrum is a genus of medium-sized evergreen trees comprising two species from Africa. " Calodendrum capense" (Cape Chestnut) is a well known tree that is widely cultivated, while "Calodendrum eickii" is a rare forest tree from Tanzania.  The botanical name comes from Greek, "kalos" means beautiful and "dendrum" means tree.  Both species are harvested for their timber in Africa.

Galeopsis bifida: Galeopsis bifida is an annual plant native to Europe and Asia but now found in Canada and the northeastern, midwestern parts of the United States.  It has many common names such as bifid hemp-nettle, split-lip hemp-nettle, common hemp-nettle, and large-flowered hemp-nettle.  The genus name means weasel-like, referring to the corolla of the flower.  It is often confused with other species of Lamiaceae such as "Mentha arvensis", "Dracocephalum parviflorum" and "Stachys pilosa".

Peppermint: Peppermint (Mentha" × "piperita, also known as "Mentha balsamea" Willd.)  is a hybrid mint, a cross between watermint and spearmint.  Indigenous to Europe and the Middle East, the plant is now widespread in cultivation in many regions of the world.  It is occasionally found in the wild with its parent species.

Plant cover: The abundances of plant species are often measured by plant cover, i.e. the relative area covered by different plant species in a small plot.  Plant cover is not biased by the size and distributions of individuals, and is an important and often measured characteristic of the composition of plant communities.  Plant cover data may be used to classify the studied plant community into a vegetation type, to test different ecological hypothesis on plant abundance, and in gradient studies, where the effects of different environmental gradients on the abundance of specific plant species are investigated.

Mentha arvensis: Mentha arvensis corn mint, field mint or wild mint, is a species of flowering plant in the mint family Lamiaceae.  It has a circumboreal distribution, being native to the temperate regions of Europe and western and central Asia, east to the Himalaya and eastern Siberia, and North America. "Mentha canadensis, the related species," is also included in "Mentha arvensis" by some authors as two varieties, "M. arvensis" var.  "glabrata" Fernald (in reference to North American plants such as American Wild Mint) and "M. arvensis" var.  "piperascens" Malinv.  ex L. H. Bailey (in reference to eastern Asian plants such as Japanese mint).

Mentha: Mentha (also known as mint, from Greek "míntha", Linear B "mi-ta") is a genus of plants in the family Lamiaceae (mint family).  It is estimated that 13 to 18 species exist, and the exact distinction between species is still unclear.  Hybridization between some of the species occurs naturally.  Many other hybrids, as well as numerous cultivars, are known.

Thymus pulegioides: Thymus pulegioides (common names broad-leaved thyme, lemon thyme) is a species of flowering plant in the family Lamiaceae, native to Europe.  Growing to 5 - tall by 25 cm wide, it is a small spreading subshrub with strongly aromatic leaves, and lilac pink flowers in early summer.  The specific epithet "pulegioides" highlights its similarity to another species within Lamiaceae, "Mentha pulegium" (pennyroyal).

Supporting paragraphs: Mentha Calodendrum
Answer: Mentha