Phitosia

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Description

Caespitose perennial with a branched woody caudex, forming large, dense clumps or mats from which the flowering stems emerge. Perennial shoots short, bearing rosulate leaves producing innovations from their axils and surrounded by the remnants of persisting brownish leaf bases. Annual stems terminal to these shoots, almost scapiform, erect, slender, up to 40(-45) cm, not or sparingly branched. Rosular leaves several, (3-)7-15 x 0.2- 0.5 cm, linear or linear-lanceolate, entire (rarely with 1-2 triangular-acuminate, up- or downcurved teeth or lobules in their middle part), glaucous, glabrous; stem leaves few and distant, resembling the basal ones but smaller, the lowermost often producing axillary innovations in the fall, the upper narrowly linear. Capitula erect, 9-15-flowered, at the end of long (up to 15 cm) peduncles which are gradually thickened upward then suddenly constricted at the base of the flower heads. Involucre 8-11 x 6-8 mm, obconical-campanulate to narrowly campanulate, sparsely appressed-canescent with simple, crispate-interwoven, uniseriate, pluricellular hairs, neither setose nor glandular. Outer phyllaries up to 10, unequal, less than ½ as long as the inner ones, linear, dark green; inner phyllaries 8-10, lanceolate, acute, glabrous on their ventral surface. Receptacle non-areolate, glabrous and naked, with only the scars of the central cypsela strands visible after fruit abscission. Corolla 9-13(-15) mm; tube glabrous; ligules up to 2.5(-3) mm wide,yellow. Cypselas 5-7 mm, smooth, yellowish brown, fusiform, with c. 20 longitudinal striae or weak ribs; gradually attenuate toward the apex then expanded into a pappus disk; carpopodium of (3-)5 ± irregularly semilunar calli surrounding a cavity with a central sclerenchyma strand to which the cypsela is attached. Pappus 5-7 mm long, 2-seriate, dirty yellowish; setae unequal, rather rigid, the larger compressed dorsiventrally in their lower part, scabrid all round with asperities that increase in density towards the base, breaking away singly from a basal coronula capping the pappus disk.

from: Kamari & Greuter in Bot. Chron. 13: 14-15. 2000.

Distribution

Europe: Greece (Greecenative)

Systematics

Phitosia is a genus established by Kamari & Greuter (2000) to accommodate the single species formerly treated as Crepis crocifolia. The species has a localised distribution in the SE Peloponnes (Kamari & al. 2011) and was apparently misplaced in Crepis. It differs from that genus, most strikingly, because of its chromosome number of 2n = 18 (Kamari & Greuter 2000: 18, fig. 3a-b, 4a-b), which is not known from the entire subtribe Crepidinae, its achene and pappus micromorphology (Kamari & Greuter 2000: 18-20, fig. 5-12) and its growth form as a cushion forming rosette shrub (Kamari & Greuter 2000: 17-18, fig. 1).

Kamari & Greuter (2000) assumed Phitosia to represent an isolated branch that arose from the common anchestral stock of the morphologically weakly differentiated crepidioid subtribes. Lack (2006) treated Phitosia as a member of subtribe Crepidinae. Essentially confirming the separation of Phitosia from Crepis, the ITS phylogeny of the tribe Cichorieae by Gemeinholzer & al. (in Kilian & al. 2009) showed Phitosia in a clade with the genera Chondrilla and Willemetia, but whereas the sister-group relationship of Chondrilla and Willemetia received strong statistical support, there was no statistical support for the more comprehensive clade with Phitosia. The placement of Phitosia along with Chondrilla and Willemetia in the subtribe Chondrillinae is therefore tentative and in need of confirmation.


References


Bremer K. 1994: Asteraceae. Cladistics and classification. – Portland: Timber.

Kamari G., Kyriakopoulos C. & Kofinas G. 2011 ["2010"]: New finding of Phitosia crocifolia (Compositae) in E Peloponnisos. – Fl. Medit. 20: 235-238.

Kilian N., Gemeinholzer B. & Lack H. W. 2009: Tribe Cichorieae. – In: Funk V. A., Susanna A., Stuessy T. & Bayer R. (ed.), Systematics, evolution, and biogeography of the Compositae. – Vienna: IAPT.

Kamari G. & Greuter W. 2000: Phitosia, a new genus for Crepis crocifolia (Compositae, Cichorieae), a local endemic of Mount Taigetos (Greece). – Bot. Chron. (Patras) 13: 11-36.

Lack H. W. 2006 ["2007"]: Tribe Cichorieae Lam. & DC. – Pp. 180-199 in: Kadereit J. W. & Jeffrey C. (ed.), The families and genera of vascular plants 8. – Berlin: Springer.

Chromosome numbers

Diploid, x = 9.A

Bibliography

A. Kamari & Greuter, Phitosia, a new genus for Crepis crocifolia (Compositae, Cichorieae), a local endemic of Mount Taigetos (Greece) in Bot. Chron. (Patras) 13