KTJNGL. SV. VET. AKADEMIENS HANULINGAR. BAND 55. N:0 5. 



113 



.str 



parts the plant presents an obvious similarity to P. folycjonus, whereas spikes and 

 pistils bear closer resemblance to P. Aschersonii. In several respects it is interme- 

 diate between the two. 



The stem is little branched beneath the primary spike. From this it shoots 

 out like P. Aschersonii. In shape it is a little compressed. The anatomic diagram 

 shows an epidermis with a one-celled pseudo-hypoderma and scattered, very strong, 

 subepidermal strands, but no inter] acunar ones. The central cylinder has an oval 

 crosscut-form with the lateral bundles separated from the median ones (oblong 

 diagram). 



Peduncle somewhat compressed; its vascular bundles being 4 in number run 

 near together. Hypoderma and subepi- 

 dermal strands as in P. Aschersonii. 



The stem-leaves remind much of a 

 polygonus-leai, but are only 50 — 60 mm 

 long by 2 mm broad. The marginal 

 strand is very strong consisting of 50 

 bast-cells or more. For the rest I refer 

 to the figure. The ligules are 6 — 7- 

 fibrous in the front-field and decay in 

 the same way as in P. polygonus by 

 leaving a whorl of nerves at the base. 



As to form and size the leaves 

 nearly correspond with those of P. orien- 

 talis, which, however, has much softer 

 leaves on account of a less developed 

 sclerenchymatous tissue. 



Distribution. Brazil: Sao Paulo. 

 Campinas, 1868, S. Henschbn (lib. Stock- 

 holm, et Uppsal.). I have seen a spe- 

 cimen from »S:a Catharina, Graben am 



Itajahy unterhalb Blumenau, 1886, H. Schenk» (hb. Berolin.), which is likely to be 

 this hybrid. — The main-form now described could be named: a strictus. 



Another form of this hybrid is found at Amparo, Pro v. S:t Paulo, of Brazil. 

 It has short internodes, thence more folygonusAWs.e. Stem-leaves 80 — 90 X 2 mm, 

 3-nerved (P. Aschers.), apex rather intermediate in shape, base always tapered; la- 

 cunar part not occupying the whole space between the midnerve and the chief lateral 

 one. Ligules open, 10 — 11-nerved in the front-field (P. polyg.), with rounded tip, 

 10 mm in young state; on decaying they leave an annulus round the stem (P. ^jo- 

 lyg.). Peduncle 25 mm in length. Spike 4 — 5-verticillate. This form I will name: 



p polygoniforinis. — Caulis internodiis brevissimis (± 10 mm). Folia quoad for- 

 mam et structuram intermedia. — The specimen examined is preserved in Hb. Univ. 

 of Copenhagen. Coll. »Lindbeeg, in 1854», ace. to the label of Baagoe. 



Fig. 48. P. ttttenuatus Hagstr. A, Base {a) .intl top (&) of a 

 stem-leaf showing the form and nervation. The primary side- 

 neivos join the midvein in the very top as in I', polyt/omis, f. 

 B, Cross-section of a stem-leaf at the middle, midrib-portion {»/) 

 and margin (sir), ca. 'j". C, Pistil, n, side-view, b, inside view, c, 

 stigma from above, y. D, Cross-section of peduncle. The four 

 vascular bundles (ci), 9 subepidermal strands (sir), Y. 



K. Bt. Vet. Akad. Handl. Band 55. N;o 5. 



15 



