Megathyrsus maximus(Jacq.) B.K.Simon & S.W.L.Jacobs

guineagrass

WFO wfo-0000878966 Accepted WFO 2026-06 8 photographs CC BY

Plate 1 figs. a–h · 8 separate observations

Megathyrsus maximus, photographed by 五色鳥
fig. a 五色鳥, CC BY 4.0 / 2022-06-07 / obs. 204024713

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

The specimen a real sheet, in a real collection

Herbarium
The New York Botanical Garden
Accession
00866239
Filed as
Megathyrsus maximus (Jacq.) B.K.Simon & S.W.L.Jacobs
Det. by
M. A. V. Heyliger 2008-03-22
Collected
S. A. Mori 2006-08-11
Origin
BQ
The sheet
View the digitised specimen (CC BY 4.0)

A real pressed plant, in a real collection, under the accession number above. Not an illustration of one. The holding institution does not serve this sheet’s image to third parties, so there is no photograph here. The record is real and the link goes to it. Where we hold no openly licensed sheet for a species this section is simply absent, and where a sheet never recorded who determined it, that field stays empty rather than being filled in. Roughly half of all herbarium sheets never recorded a determiner, which is ordinary.

Native range 53 botanical countries

Regions where Megathyrsus maximus is native: Aldabra, Angola, Benin, Botswana, Burkina, Burundi, Cameroon, Cape Provinces, Central African Republic, Chad, Comoros, Congo, DR Congo, Eritrea, Eswatini, Ethiopia, Free State, Gabon, Gambia, Ghana, Guinea, Guinea-Bissau, Gulf of Guinea Is., Ivory Coast, Kenya, KwaZulu-Natal, Liberia, Madagascar, Malawi, Mauritius, Mozambique, Mozambique Channel Is., Namibia, Nigeria, Northern Provinces, Réunion, Rodrigues, Rwanda, Senegal, Seychelles, Sierra Leone, Socotra, Somalia, Sudan-South Sudan, Tanzania, Togo, Uganda, Zambia, Zimbabwe, Gulf States, Oman, Saudi Arabia, Yemen AngolaBeninBotswanaBurkinaBurundiCameroonCape ProvincesCentral African RepublicChadCongoDR CongoEritreaEswatiniEthiopiaFree StateGabonGambiaGhanaGuineaGuinea-BissauGulf of Guinea Is.Ivory CoastKenyaKwaZulu-NatalLiberiaMadagascarMalawiMozambiqueNamibiaNigeriaNorthern ProvincesRwandaSenegalSierra LeoneSomaliaSudan-South SudanTanzaniaTogoUgandaZambiaZimbabweGulf StatesOmanSaudi ArabiaYemen AldabraComorosMauritiusMozambique Channel Is.RéunionRodriguesSeychelles
Native distribution of Megathyrsus maximus, after Kew’s World Checklist of Vascular Plants. Introduced, extinct and doubtful records are excluded, so this is where the plant is from, not everywhere it now grows. Regions too small to draw at this scale are marked with a dot.
RegionTDWG codeContinent
Aldabra ALD AFRICA
Angola ANG
Benin BEN
Botswana BOT
Burkina BKN
Burundi BUR
Cameroon CMN
Cape Provinces CPP
Central African Republic CAF
Chad CHA
Comoros COM
Congo CON
DR Congo ZAI
Eritrea ERI
Eswatini SWZ
Ethiopia ETH
Free State OFS
Gabon GAB
Gambia GAM
Ghana GHA
Guinea GUI
Guinea-Bissau GNB
Gulf of Guinea Is. GGI
Ivory Coast IVO
Kenya KEN
KwaZulu-Natal NAT
Liberia LBR
Madagascar MDG
Malawi MLW
Mauritius MAU
Mozambique MOZ
Mozambique Channel Is. MCI
Namibia NAM
Nigeria NGA
Northern Provinces TVL
Réunion REU
Rodrigues ROD
Rwanda RWA
Senegal SEN
Seychelles SEY
Sierra Leone SIE
Socotra SOC
Somalia SOM
Sudan-South Sudan SUD
Tanzania TAN
Togo TOG
Uganda UGA
Zambia ZAM
Zimbabwe ZIM
Gulf States GST ASIA-TEMPERATE
Oman OMA
Saudi Arabia SAU
Yemen YEM

Not drawn on the map: Socotra. We hold no public-domain boundary for this region, so it is listed rather than guessed at.

Region boundaries approximated from Natural Earth (public domain) and mapped to TDWG World Geographical Scheme for Recording Plant Distributions (WGSRPD) level-3 botanical countries (Brummitt 2001). Indicative, not the official WGSRPD geometry.

Flowering 356 in flower of 660 examined

Proportion of examined Megathyrsus maximus in flower, by month
Month In flower Examined Share 95% interval
Jan 11 32 34% 20% to 52%
Feb 8 28 29% 15% to 47%
Mar 22 43 51% 37% to 65%
Apr 44 92 48% 38% to 58%
May 37 62 60% 47% to 71%
Jun 41 80 51% 40% to 62%
Jul 42 67 63% 51% to 73%
Aug 32 58 55% 42% to 67%
Sep 39 59 66% 53% to 77%
Oct 44 64 69% 57% to 79%
Nov 17 35 49% 33% to 64%
Dec 19 40 48% 33% to 63%

Peak flowering in Oct. Each bar is the share of Megathyrsus maximus observations in which someone actually recorded the reproductive state and found the plant in flower, not the raw number of flowering records. That distinction matters: people observe plants far more in spring than in winter, so a bare count of flowering records partly measures when people go outside. Dividing by the number examined removes that. 356 of 660 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. This is still a global aggregate and not a forecast for your garden: the same species flowers on different dates in different hemispheres. Where a species has fewer than 30 flowering records we do not draw this chart at all. Computed from 10.15468/dl.cgje2x.

Where it actually grows measured, from 1,999 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low 7.0 °C 13.7 °C 21.6 °C
Warmest month, mean daily high 24.9 °C 29.3 °C 35.1 °C
Annual rainfall 623 mm 1,301 mm 3,180 mm
Rainfall in the driest quarter 47 mm 122 mm 537 mm

It is barely found anywhere that freezes. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 1,999 research-grade observations of Megathyrsus maximus that carry a coordinate, and this is the range those places actually span. The 5th and 95th percentiles are used rather than the minimum and maximum, because a single cultivated specimen in a heated conservatory should not widen a tropical plant's range to the Arctic.

This is not a hardiness zone. A USDA zone is the average annual extreme minimum temperature. The figure above is the mean daily minimum of the coldest month, which is a different quantity and is typically far warmer. Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one. Climate from CHELSA V2.1 (Karger et al. 2017); occurrences from 10.15468/dl.cgje2x.

Named cultivars 2 recorded

Selections of Megathyrsus maximus that somebody named and propagated. A cultivar is not a botanical taxon: it is governed by the cultivated-plant code rather than the botanical one, so it appears in no taxonomic backbone, and it has no native range and no wild population of its own. These get no page here, because a cultivar has no photographs, no range and no flowering data of its own, and a page with none of those is not a page.

From Wikidata (CC0), joined to this species on its World Flora Online identifier, so the link to the parent is exact rather than a name match. This list is what is recorded in an openly licensed register; it is not every cultivar that exists, and for many genera it is not close. Why, and how far short it falls.

Also published as 45 synonyms

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

  • Megathyrsus bivonanus (Brullo, Miniss., Scelsi & Spamp.) Verloove
  • Megathyrsus maximus var. coloratus (C.T.White) B.K.Simon & S.W.L.Jacobs
  • Megathyrsus maximus var. pubiglumis (K.Schum.) B.K.Simon & S.W.L.Jacobs
  • Milium arundinaceum J.Koenig ex Steud.
  • Panicum airoides Flüggé ex Nees
  • Panicum bivonanum Brullo, Miniss., Scelsi & Spamp.
  • Panicum compressum Biv.
  • Panicum confine Hochst. ex A.Rich.
  • Panicum eburneum Trin.
  • Panicum giganteum Mez
  • Panicum heynii Roth
  • Panicum hirsutissimum Steud.
  • Panicum jumentorum Pers.
  • Panicum laeve Lam.
  • Panicum mahafalense A.Camus
  • Panicum mananarense A.Camus
  • Panicum maximum Jacq.
  • Panicum maximum subsp. commune (Nees) Peter
  • Panicum maximum subsp. pubescens M.Sharma
  • Panicum maximum var. altissimum Kuntze
  • Panicum maximum var. coloratum C.T.White
  • Panicum maximum var. commune Nees
  • Panicum maximum var. confine Chiov.
  • Panicum maximum var. effusum A.Camus

and 21 more.

Sourcesevery claim on this page

  1. World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
  2. iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
  3. USDA PLANTS Database. common name, checklist symbol URMA3. public domain. Retrieved 2026-07-13.
  4. Kew, World Checklist of Vascular Plants (WCVP v16). native distribution by TDWG level-3 botanical country, and life form. CC BY 3.0. Retrieved 2026-06-04.

We publish what we can source and we say so when we cannot. This page has no care advice and no toxicity claim, because we do not yet have those from a source we can cite.