Two additions to the Asteraceae of Egypt

The novel occurrence of Helenium amarum (Raf.) H. Rock var. amarum and Pulicaria dysenterica (L.) Gaertn. (Asteraceae) in the flora of Egypt is reported. Apart from the single collection of H. amarum var. amarum in Australia, this taxon was not recorded previously outside its country of origin in South-Eastern United States and Mexico. With the recording of Pulicaria dysenterica in Egypt, Libya remains the only Mediterranean country where it has not as yet been found. Detailed description of the two species in terms of 83 characters is provided. A data matrix including the eight Pulicaria species found in Egypt and 19 of their morphological characters was compiled and a conventional key was constructed using the key-generating computer program suit DELTA.


Introduction
In the course of preparing a comprehensive data base of the Asteraceae in Egypt (El-Gazzar et al., 2019 a, b), we came across some specimens in the holdings of the herbarium of Cairo University (CAI) collected in widely separated localities in Egypt and representing two different taxa: a single specimen of Helenium amarum (Raf.) H. Rock var. amarum (kept as Helenium tenuifolium Nutt.) and three specimens of Pulicaria dysenterica (L.) Gaertn. Although the specimen of Helenium amarum (Raf.) H. Rock var. amarum was collected by M. Hassib in Sinai in April 1940, it was not until August 1972 when it was identified at Kew by C. Jeffrey. The three specimens of Pulicaria dysenterica (L.) Gaertn. were collected in different localities east of the Nile Delta during 1980 and 1981. The two taxa were overlooked in subsequent floras of Egypt (e.g. Täckholm, 1974;El-Hadidi andFayed, 1994/1995;Boulos and Hind, 2002) and in detailed floristic revisions of the family (Fayed and Mohamed, 1991;Zareh, 2005a and2005b).
The data base established by us specifically for the Asteraceae of Egypt consists of two parts. The first part (El-Gazzar et al., 2019a) is devoted entirely to the spiny taxa and consists of 51 characters recorded for 65 species belonging to 20 genera. The second part (El-Gazzar et al., 2019b) is concerned solely with the more 15 numerous spineless taxa of the family and encompasses 195 states of 83 characters recorded for each of 158 species from 77 genera.
The present article aims to add Helenium amarum (Raf.) H. Rock var. amarum and Pulicaria dysenterica (L.) Gaertn. to the spineless taxa representing the Asteraceae in the flora of Egypt and to provide detailed descriptions for them.

Materials and Methods
Collection data of the specimens located in the Cairo University Herbarium (CAI) and used in the present study as material evidence of the occurrence of two species of Asteraceae in the flora of Egypt are as follows: Helenium  (Figure 2).
Identification of the two species was verified with the help of appropriate floras (e.g. Andrews, 1956;Feinbrun-Dothan, 1977, 1978Barkley et al., 2006;Bierner, 2006), the monograph of Pulicaria by Gamal-Eldin (1981) and the flora of China (Chen and Anderberg, 2018) for Pulicaria dysenterica. Nomenclature was updated according to the two websites of The Plant List (2016) and The Missouri Botanical Garden (2017).
In order to distinguish between the eight Pulicaria species in Egypt, a conventional key was generated using a set of 19 morphological characters recorded for each of them and the key-generating program DELTA (Dallwitz et al., 1993 onwards;Dallwitz and Paine, 2005).

Results and Discussion
The following are the detailed descriptions of the two species added for the first time to the Asteraceae of Egypt as extracted from the data base established by us (El-Gazzar et al., 2019b) for the spineless representatives of the family in the local flora.    To distinguish between the two newly recorded taxa (Helenium amarum var. amarum and Pulicaria dysenterica) and the rest of genera and species representing the Asteraceae in the flora of Egypt, they have been incorporated into a computer-generated conventional key to the spineless taxa of this family (El-Gazzar et al., 2019b) based on 83 characters recorded for every taxon. With the addition of both taxa, the spineless Asteraceae are represented in Egypt by 160 species belonging to 78 genera.
The occurrence of Helenium amarum var. amarum in the mountainous area of southern Sinai is a new generic and specific record in the flora of Egypt. It also seems to be the only record of this taxon outside its country of origin in South-Eastern United States and Mexico and a single locality in Australia.
Helenium amarum (Raf.) H. Rock var. amarum is widespread in the south-eastern United States and California (USDA, 2018) and Mexico. The two specimens of this taxon cited by Bean (2015) indicate that they were collected in 1953 and 2007 from one location in Lowood District, Mount Tarampa aerodrome in the Lockyer Valley of Queensland, Australia, where it was reported to be poisonous to livestock and competes with pasture and native vegetation. This is so far the only record of this species and its variety outside the Americas. Bean (2015) also reported that Mount Tarampa aerodrome was used by the United States Air Force during World War II, which might explain the accidental introduction of this exclusively American species into Australia. Ecologically, H. amarum var. amarum prefers open fields, roadsides and disturbed areas in subhumid, warm temperate and subtropical areas in USA and Australia where annual rainfall is less than 1000 mm and the soil are calcareous, sandy, loam or clay loam (Anonymous, 2016). Such environmental conditions are closely similar to those prevailing in the valleys of the central and southern parts of the Sinai Peninsula, Egypt, where the only collection of the species was made. It is interesting to note that this locality is part of the passage of a continuous stream of religious tourism to St. Catherine Monastery in southern Sinai, which might have accidentally brought this taxon to this otherwise uninhabited spot.

Conclusions
Despite the continuous efforts of the amateur and professional botanists who studied the flora of Egypt for more than 250 years, this flora is so dynamic that new records can still be made. While the predominantly Mediterranean species Pulicaria dysenterica may be regarded as native, the almost exclusively American taxon Helenium amarum var. amarum is decidedly alien in Egypt.